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Epson 4051N Printer User Manual

1. SERVICE MANUAL KOHLER COMMAND cu18 745 HORIZONTAL CRANKSHAFT KOHLER lm US CH18 745 Section 1 Safety and General Information Safety Precautions To ensure safe operation please read the following statements and understand their meaning Also refer to your equipment manufacturer s manual for other important safety information This manual contains safety precautions which are explained below Please read carefully A WARNING Warning is used to indicate the presence of a hazard that can cause severe personal injury death or substantial property damage if the warning is ignored A CAUTION Caution is used to indicate the presence of a hazard that will or can cause minor personal injury or property damage if the caution is ignored NOTE Note is used to notify people of installation operation or maintenance information that is important but not hazard related For Your Safety These precautions should be followed at all times Failure to follow these precautions could result in injury to yourself and others amp WARNING A WARNING AA WARNING adi Accidental Starts can cause Rotating Parts can cause severe Hot Parts can cause severe burns severe injury or death injury Do not touch engine while operating Disconnect and ground spark plug Stay away while engine is in or just after stopping leads before servicing operation Accidental Starts Rotating Parts Hot Parts Disabli
2. 41 kg 90 Ib GEHZ9 CH2Z6 CU 7302145 xii aoe ache kee onc ddd aed eee E 43 kg 94 Ib Oil Capacity with filter CH18 CH20 CH22 23 CH25 CH26 CH730 745 esses 1 9 L 2 0 U S qt Angle of Operation Maximum At Full Oil Level All Directions esses 25 Blower Housing and Sheet Metal MS Fasteners Lee m T Tad E E 4 0 N m 35 in Ib WIG EN TOUS ae em 6 8 N m 60 in Ib Rectifier Regulator Fastener Torque nennen nennen 4 0 N m 35 in Ib Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 1 8 Section 1 Safety and General Information Camshaft rid EVER On eem PD E 0 076 0 127 mm 0 0030 0 0050 in D Running CIC ALAN C EE 0 025 0 063 mm 0 0010 0 0025 in Bore I D pr EN 20 000 20 025 mm 0 7874 0 7884 in Max Near M 20 038 mm 0 7889 in Camshaft Bearing Surface O D MI EE 19 962 19 975 mm 0 7859 0 7864 in Max Wear IM 19 959 mm 0 7858 in Carburetor and Intake Manifold Intake Manifold Mounting Fastener Torque Torque IN TWO Ee EE initially to 7 4 N m 66 in Ib finally to 9 9 N m 88 in Ib Carburetor Mounting Screw Torque M 6 2 7 3 N m 55 65 in Ib Adapter for Heavy Duty Air Cleaner Mounting Fastener Torque 7 3 N m 65 in Ib Connecting Rod Cap Fas
3. Section 5B EFI Fuel System Fuel Components Fuel Pump External Internal Figure 5B 26 Fuel Pump Styles General An electric fuel pump is used to transfer fuel in the EFI system Depending on the application the pump may be inside the fuel tank or in the fuel line near the tank The pumps are rated for a minimum output of 25 liters per hour at 39 psi The pumps have an internal 60 micron filter In addition the in tank style pumps will have a pre filter attached to the inlet In line pump systems may also have a filter ahead of the pump on the pick up low pressure side The final filter is covered separately on page 5B 22 When the key switch is turned on and all safety switch requirements are met the ECU through the relay activates the fuel pump which pressurizes the system for start up If the key switch is not promptly turned to the start position the engine fails to start or the engine is stopped with the key switch on as in the case of an accident the ECU switches off the pump preventing the continued delivery of fuel In this situation the MIL will go on but it will go back off after 4 cranking revolutions if system function is OK Once the engine is running the fuel pump remains on Service The fuel pumps are non serviceable and must be replaced if determined to be faulty If a fuel delivery problem is suspected make certain the pump is being activated through the relay all electrical conn
4. Figure 11 48 Installing Spark Plugs Install Ignition Modules 1 Rotate the flywheel to position the magnet away from the ignition module bosses 11 14 Figure 11 49 Installing Ignition Module 2 On engines equipped with SMART SPARK both modules are installed the same way with the two tabs out See Figure 11 55 On engines are not equipped with SMART SPARK the modules are installed with the spark plug lead wire from module always away from the cylinder On 1 cylinder the single kill tab should be towards you See Figure 11 54 On 2 cylinder the single kill tab should be away from you in Install each ignition module to the crankcase bosses with the two screws hex flange or allen head based on model Slide the modules up as far away from the flywheel as possible and snug the screws to hold them in that position Rotate the flywheel to position the magnet directly under one ignition module Insert a 0 30 mm 0 012 in flat feeler gauge between the magnet and the ignition module See Figure 11 50 Loosen the screws enough to allow the magnet to pull the module down against the feeler gauge Section 11 Reassembly Figure 11 52 Sealant Applied to Terminals 6 Torque the screws to 4 0 N m 35 in Ib NOTE If the wires were disconnected from the ignition modules on engines with SMART 7 Repeat steps 4 through 6 for the other ignition SPARK reattach the leads and seal the module
5. Intermittent 5 volt source from ECU pin circuit 14 5B 37 Section 5B EFI Fuel System 3 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pincircuits 4 8 and or 18 damaged wiring connectors b Pin circuits 4 8 and or 18 routed near noisy electrical signal coils alternator c Intermittent 5 volt source from ECU pin circuit 18 4 ECU Harness Related a ECU to harness connection problem Code 23 Source ECU Explanation ECU is unable to recognize or process signals from its memory Expected Engine Response Engine will not run Possible Causes 1 ECU internal memory problem a Diagnosable only through the elimination of all other system component faults Code 24 Will not blink out Source Engine Speed Sensor Explanation No tooth signal from speed sensor MIL light will not go out when cranking Expected Engine Response None engine will not start or run as ECU is unable to estimate speed Possible Causes 1 Engine Speed Sensor Related a Sensor connector or wiring b Sensor loose or air gap incorrect 2 Speed Sensor Wheel Related a Damaged teeth b Gap section not registering 3 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin s 3 and or 21 for 35 Pin MA 1 7 Metal Cased ECU Pin s 9 and or 10 for 24 Pin MSE 1 0 Plastic Cased ECU Pin s 9 and or 10 for 32 Pin MSE 1 1 Plastic Cased ECU 4
6. 32 Pin MSE 1 1 Plastic Cased ECU Circuits circuits 9 and 10 30 31 65 66 relay and relay circuit 30 3 Speed sensor toothed wheel air gap 5 ECU grounds 4 Toothed wheel 6 ECU 5 Flywheel key sheared 6 ECU Diagnostic Aid 8 FUEL SYSTEM ELECTRICAL no fuel delivery Diagnostic Aid 5 FUEL PUMP fuel pump not turning on Possible causes 1 No fuel Possible causes 2 Airin fuel rail 1 Fuel pump fuse 3 Fuel valve shut off 2 Fuel pump circuit problem 4 Fuel filter line plugged 35 Pin MA 1 7 Metal Cased ECU Circuits 5 Injector circuit s 43 44 and relay 35 Pin MA 1 7 Metal Cased ECU Circuits 24 Pin MSE 1 0 Plastic Cased ECU Circuits 35 35A 45 and 45A 30 87 and relay 24 Pin MSE 1 0 Plastic Cased ECU Circuits 32 Pin MSE 1 1 Plastic Cased ECU Circuits 16 17 45 and 45A 30 87 and relay 32 Pin MSE 1 1 Plastic Cased ECU Circuits 3 Fuel pump 14 15 and 45 6 Injector Diagnostic Aid 6 RELAY relay not operating 7 ECU grounds 8 ECU Possible causes 1 Safety switches circuit s problem Diagnostic Aid 9 FUEL SYSTEM fuel pressure 35 Pin MA 1 7 Metal Cased ECU Circuits 41 and 41A Possible causes for low fuel system pressure 24 Pin MSE 1 0 Plastic Cased ECU Circuit 1 Low fuel 3 2 Fuel filter plugged 32 Pin MSE 1 1 Plastic Cased ECU Circuit 3 Fuel supply line plugged 25 4 Pressure regulator 2 Relay circuit s proble
7. Section 8 Electrical System and Components Style B Drive Service 1 The rubber dust cover has a molded lip on the inside that snaps into a groove in the dust cover spacer see Figure 8 31 Turn the drive pinion clockwise until it reaches the fully extended position While holding it in the extended position grasp the tip of the dust cover with a pliers or vise grip and pull it free from the spacer Retaining Ring Anti Drift Sprin P pring S Dust Cover De Spacer Drive Pinion P A Drive Nu O Collar Figure 8 31 Drive Components Bonded Inertia Drive Starter 2 Disassemble the snap ring removal tool SPX Part No KO1049 formerly Kohler Part No 25 761 18 S 3 Again referring to Figure 8 31 grasp the spring retainer and push it toward the starter compressing the anti drift spring and exposing the retaining ring 4 Holding the spring retainer in the retracted position assemble the inner halves of the removal tool around the armature shaft with the retaining ring in the inner groove see Figure 8 32 Slide the collar over the inner halves to hold them in position 8 24 Figure 8 32 Assembling Inner Half of Tool Around Armature Shaft and Retaining Ring D Thread the center screw into the removal tool until you feel resistance Use a wrench 1 1 8 or adjustable to hold the base of the removal tool Use another wrench or socket 1 2 or 13 mm to turn the center screw
8. Disassembly A WARNING Accidental Starts Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery General Clean all parts thoroughly as the engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Typical Disassembly Sequence The following sequence is suggested for complete engine disassembly The sequence can be varied to accommodate options or special equipment Disconnect spark plug leads Shut off fuel supply Drain oil from crankcase and remove oil filter Hemove muffler Remove air cleaner assembly Remove control panel if so equipped Remove fuel pump Remove throttle controls Remove external governor controls 10 Remove carburetor 11 Remove electric starter motor 12 Remove outer baffles and blower housing 13 Remove Oil Sentry if so equipped 14
9. Section 3 Troubleshooting To test the crankcase vacuum with the manometer 1s Insert the stopper hose into the oil fill hole Leave the other tube of manometer open to atmosphere Make sure the shut off clamp is closed Start the engine and run at no load high speed 3200 to 3750 RPM Open the clamp and note the water level in the tube The level in the engine side should be a minimum of 10 2 cm 4 in above the level in the open side If the level in the engine side is less than specified low no vacuum or the level in the engine side is lower than the level in the open side pressure check for the conditions in the table on page 3 4 Close the shut off clamp before stopping the engine To test the crankcase vacuum with the Vacuum Pressure Gauge Kit SPX Part No KO3223 1 2 Remove the dipstick or oil fill plug cap Install the adapter into the oil fill dipstick tube opening upside down over the end of a small diameter dipstick tube or directly into engine if a tube is not used Push the barbed fitting on the gauge solidly into the hole in the adapter Start the engine and bring it up to operating speed 3200 3600 RPM Check the reading on the gauge If the reading is to the left of O on the gauge vacuum or negative pressure is indicated If the reading is to the right of O on the gauge positive pressure is present Crankcase vacuum should be 4 10 inches of water If the r
10. Torx Head Screw Vac Lock Diaphragm Assembly 11 Vac Lock Spring Figure 5A 20 17 18 19 20 21 Secondary Lever Assembly Adjustment Screw Pan Head Screw Expansion Plug Diaphragm Gasket Split Lock Washer Nikki Regulator Primary Chamber See Figure 5A 21 The primary chamber reduces the high pressure fuel flow from the tank and vaporizer down to approximately 4 psi Fuel flowing from the vaporizer enters the inlet of the regulator under approximately 76 kPa 11 psi of pressure There it is delivered to the primary chamber 3 through the clearance between the primary valve 1 and valve seat 2 As fuel continues to flow and the primary chamber approaches 29 kPa 4 psi the primary diaphragm 4 overcomes the tension of the diaphragm spring 5 As the diaphragm 4 and contact button 6 move up the primary lever spring 8 pushes the primary lever 7 up in turn closing the primary valve 1 and stopping the flow of fuel As fuel is consumed and the pressure in the primary chamber drops below 29 kPa 4 psi the diaphragm spring 5 tension will be greater than the fuel pressure causing the primary diaphragm 4 to be pushed down This causes the contact button 6 to push the primary lever 7 down in turn opening the primary valve 1 and admitting more fuel In this manner the pressure within the primary chamber is maintained at a relatively constant 29 kPa 4 psi To Secondary Chamber 1 Primary
11. Year Year 1991 2000 1992 2001 1993 2002 1994 2003 1995 2004 1996 2005 1997 1998 1999 Figure 1 2 Explanation of Engine Identification Numbers 1 3 Section 1 Safety and General Information Oil Recommendations Fuel Recommendations Using the proper type and weight of oil in the crankcase is extremely important So is checking oil daily and A WARNING Explosive Fuel changing oil regularly Failure to use the correct oil or Gasoline is extremely flammable and its vapors can using dirty oil causes premature engine wear and failure explode if ignited Before servicing the fuel system make sure there are no sparks open flames or other Oil Type sources of ignition nearby as these can ignite gasoline Use high quality detergent oil of API American vapors Disconnect and ground the spark plug leads to Petroleum Institute Service Class SG SH SJ or prevent the possibility of sparks from the ignition higher Select the viscosity based on the air temperature system at the time of operation as shown in the following table General Recommendations Purchase gasoline in small quantities and store in clean approved containers A container with a capacity of 2 gallons or less with a pouring spout is 2W 20 9W 30 recommended Such a container is easier to handle RECOMMENDED SAE VISCOSITY GRADES and helps eliminate spillage during refueling Kohler Command DS 1 Do not use gasoline left over from the previous
12. flange screws or hex flange nuts and washers on studs Do not interchange or mix components as the cylinder heads may have different machining unique to each fastening method Remove the four hex flange screws or hex nuts and washers securing each cylinder head See Figure 9 46 Discard the screws or nuts and washers once removed Do not reuse Studs if present should only be removed if damaged or if cylinder reconditioning is necessary Once removed they must be replaced Hex Flange Screw Hex Flange Nut and Washer Figure 9 46 Removing Cylinder Head Fasteners 2 Markthe position of the push rods as either intake or exhaust and cylinder 1 or 2 Push rods should always be reinstalled in the same positions 3 Carefully remove the push rods cylinder heads and head gaskets See Figure 9 47 Figure 9 47 Removing Cylinder Head Assembly 4 Remove the lifters from the lifter bores Use Hydraulic Lifter Tool SPX Part No KO1044 Do not use a magnet to remove lifters Mark the lifters by location as either intake or exhaust and cylinder 1 or 2 Hydraulic lifters should always be reinstalled in the same position See Figures 9 48 and 9 49 NOTE The exhaust lifters are located on the output shaft side of the engine while the intake lifters are located on the fan side of the engine The cylinder head number is embossed on the outside of each cylinder head See Figure 9 50 Section 9 Disassembly N f d
13. 0 2559 in Guide I D 7 038 7 058 mm 0 2771 0 2779 in 7 038 7 058 mm 0 2771 0 2779 in Valve Head Diameter 33 37 33 63 mm 1 3138 1 3240 in 29 37 29 63 mm 1 1563 1 1665 in Valve Face Angle 45 45 Valve Margin Min 1 5 mm 0 0591 in 1 5 mm 0 0591 in Valve Stem Diameter 6 982 7 000 mm 0 2749 0 2756 in 6 970 6 988 mm 0 2744 0 2751 in Figure 10 6 Valve Details A B C D E F G H Hard starting or loss of power accompanied by high Then carefully inspect each valve for defects such as fuel consumption may be symptoms of faulty valves a warped head excessive corrosion or a worn stem Although these symptoms could also be attributed to end Replace valves found to be in bad condition A worn rings remove and check the valves first After normal valve and valves in bad condition are shown in removal clean the valve heads faces and stems with the accompanying illustrations a power wire brush 10 5 Section 10 Inspection and Reconditioning Normal Even after long hours of operation a valve Leakage A poor grind on face or seat of valve will can be reconditioned and reused if the face and allow leakage resulting in a burned valve on one side margin are in good shape If a valve is worn to where only the margin is less than 1 32 do not reuse it The valve shown was in operation for almost 1000 hours under controlled test conditions Bad Condition The valve depicted here should be Cokin
14. 5 Cla 3601 3800 4 Clear 3451 3600 3 Clear sch MM C ROO Governor idle Hole 39013450 2 Geer povemor 31013800 4 Pupe O 2951234000 3 Pupe dH 1 J1 am 3755 Clear 596 Regulation others Tem 11 23 Section 11 Reassembly 8 mm Governor Lever and Hole Position RPM Charts z 4 S 3 Governor Lever o a 1 O00 CH18 Engines B Intended Non Accelerator Accelerator Governor Shaft High ate RPM Pump Carburetor Pump Carburetor Configuration Spring Color Hole No Spring Color Hole No Lm m owe 5 o N Standard Parent Material pn n cd4c P zb zk PN GO CO CO CH20 740 Engines Intended Non Accelerator Accelerator Governor Shaft High ate RPM Pump Carburetor Pump Carburetor Configuration Spring Color Hole No Spring Color Hole No el m sw Jig J Standard Parent Material N M zk M bi GO GO GO P zk zk PN PK LO GO W CH26 CH745 EFI Engines Governor Shaft Maximum RPM Configuration High Idle WOT Spring Color Hole No Standard Parent Material 3 3 3 2 2 1 1 1 11 24 Section 11 Reassembly Description Bracket speed control Clamp cable some applications Kill Switch some applications Lever choke top position Lever throttle control middle Linkage choke control Lever throttle actuator bottom Screw M5x0 8x20 Was
15. Check oil cooler fins cean as necessary if equipped SES 6 Every 500 Hours e Have solenoid shift starter disassembled and cleaned Section 8 Perform these maintenance procedures more frequently under extremely dusty dirty conditions Have a Kohler Engine Service Dealer perform this service Cleanout Kits 25 755 20 S black or 25 755 21 S gold allow cooling areas to be cleaned without removing shrouds Storage If the engine will be out of service for two months or more use the following storage procedure 1 Clean the exterior surfaces of the engine On Electronic Fuel Injected EFI engines avoid spraying water at the wiring harness or any of the electrical components 2 Change the oil and oil filter while the engine is still warm from operation See Change Oil and Oil Filter in Section 6 3 he fuel system must be completely emptied or the gasoline must be treated with a stabilizer to prevent deterioration If you choose to use a stabilizer follow the manufacturer s recommendations and add the correct amount for the capacity of the fuel system Fill the fuel tank with clean fresh gasoline Run the engine for 2 to 3 minutes to get stabilized fuel into the rest of the system Close the fuel shut off valve when the unit is being stored or transported To empty the system run the engine until the tank and the system are empty Remove the spark plugs and add one tablespoon of engine oil into each
16. Figure 5B 11 Oxygen Sensor Service General Like the other sensors already discussed the oxygen The oxygen sensor functions like a small battery sensor is a non serviceable component Complete generating a voltage signal to the ECU based upon replacement is required if it is faulty The sensor and the difference in oxygen content between the exhaust wiring harness can be checked as follows gas and the ambient air NOTE All tests should be conducted with a good quality high impedance digital VOA meter for accurate results 5B 11 Section 5B EFI Fuel System 1 Oxygen sensor must be hot minimum of 400 C 25 F Run engine for about 5 minutes With the engine running disconnect the oxygen sensor lead from the wiring harness Set VOA meter for DC volts and connect the red lead to the disconnected sensor lead and the black lead to the sensor shell Check for a voltage reading between 0 2 v 1 0 v a If voltage is in the specified range go to Step 2 b If the voltage is not in the specified range reconnect the oxygen sensor lead With the lead connected probe or connect the sensor connection with the red VOA meter lead Attach the black VOA meter lead to a known good ground location Start and run the engine at 3 4 throttle and note the voltage output The reading should cycle between 0 2 v 1 0 v which indicates the oxygen sensor is functioning normally and also the fuel delivery controlled by the ECU is within
17. Phillips Head Screws d m Figure 8 41 Removing Solenoid Screws 3 Ifthe solenoid was mounted with Phillips head screws separate the solenoid and plunger spring from the drive end cap If the solenoid was mounted with external Torx head screws the plunger is part of the solenoid unhook the plunger pin from the drive lever Remove the gasket from the recess in the housing See Figures 8 42 and 8 43 Figure 8 43 Removing Plunger 4 Remove the two thru larger bolts See Figure 8 44 8 29 Section 8 Electrical System and Components 7 Remove the drive lever pivot bushing and backing plate from the end cap See Figure 8 47 Figure 8 44 Removing Thru Bolts 5 Remove the commutator end plate assembly l containing the brush holder brushes springs and Figure 8 47 locking caps Remove the thrust washer from inside the commutator end See Figure 8 45 8 Take out the drive lever and pull the armature out of the drive end cap See Figure 8 48 9 Remove the thrust washer from the armature shaft See Figure 8 48 Figure 8 45 Removing Commwutator End Plate Assembly 6 Remove the frame from the armature and drive end cap See Figure 8 46 Figure 8 48 Armature and Lever Removed 10 Push the stop collar down to expose the retaining ring See Figure 8 49 Figure 8 46 Starter Frame Removed 8 30 Section 8 Electrical System and Components Figure 8 49 Retaining Ring Detail Fi
18. T 7 Paper Element Service Standard Type Every 100 hours of operation more often under extremely dusty or dirty conditions replace the paper element Follow these steps 1 Unhook the latches or loosen the retaining knob and remove the cover Remove the wing nut element cover and paper element with precleaner if so equipped Remove the precleaner if so equipped from the paper element Service the precleaner as described in Precleaner Service Do not wash the paper element or use pressurized air as this will damage the element Replace a dirty bent or damaged element with a genuine Kohler element Handle new elements carefully do not use if the sealing surfaces are bent or damaged Section 4 Air Cleaner and Air Intake System 5 Checkthe seal for any damage or deterioration 7 Reinstall the air cleaner cover and secure with the Replace as necessary See Figure 4 7 latches or the retaining knob 6 Reinstall the seal paper element precleaner NOTE Make sure the correct depth air cleaner element cover and wing nut element and rubber seal are used for the engine spec involved Some engines use a deeper or extra capacity air cleaner and a longer rubber seal Cover Knob ur Air Cleaner C Ge Anon Cover Ae T ASKEL Air Cleaner aici Cover Spring Lever 5 Latch Nut Latch Lever u Pin ce Inner Air Cleaner Cover Precleaner 5 2 Element c l
19. and Black negative ohmmeter lead to 4 pin terminal 32 Pin MSE 1 1 Plastic Cased ECU Red positive ohmmeter lead to 8 pin terminal and Black negative ohmmeter lead to 4 pin terminal Mounted Throttle wa Position Sensor E Hold the throttle closed and check the resistance It should be 800 1200 Q Figure 5B 7 TPS Location 5B 7 Section 5B EFI Fuel System 4 Leave the leads connected to the pin terminals as described in step 3 Rotate the throttle shaft slowly counterclockwise to the full throttle position Monitor the dial during rotation for indication of any momentary short or open circuits Note the resistance at the full throttle position It should be 1800 3000 Q 5 Disconnect the main wiring harness connector from the TPS leaving the TPS assembled to the manifold Refer to the chart below and perform the resistance checks indicated between the terminals in the TPS switch with the throttle in the positions specified Throttle Between Resistance 800 1200 1800 3000 1800 3000 800 1200 1600 2500 If the resistance values in steps 3 4 and 5 are within specifications go to step 6 If the resistance values are not within specifications or a momentary short or open circuit was detected during rotation step 4 the TPS needs to be replaced go to step 7 6 Check the TPS circuits input ground between the TPS plug and the main harness connector for continuity damage etc See
20. connections are not location specific 4 Connect the remaining black lead from the tester to one of the outer AC terminals on the rectifier regulator See Figure 8 25 Pa lt Figure 8 23 a If the OK green light comes on and stays steady the part is good and may be used b If any other light is displayed the rectifier regulator is faulty and should not be used Figure 8 25 NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure 5 Plug the tester into a 110 volt AC outlet and turn on the power switch The POWER light should be illuminated and one of the four status lights may be on as well See Figure 8 22 This does not represent the condition of the part 8 17 Section 8 Electrical System and Components 6 Press the TEST button until a click is heard and then release See Figure 8 23 Momentarily one of the four lights will illuminate indicating the partial condition of the part a Ifthe OK green light comes on disconnect the tester black lead attached to one AC terminal and reconnect it to the other AC terminal Repeat the test If the OK green light comes on again the part is good and may be used b If any other light is displayed in either of the tests the rectifier regulator is faulty and should not be used NOTE A flashing LOW light can al
21. holder See Figure 5B 31 Figure 5B 31 Internal Regulator and Base Holder 5 Always use new O Rings and hose clamps when installing a regulator A new replacement regulator will have new O Rings already installed Lubricate the O Rings external regulator with light grease or oil amp Install the new regulator by carefully pushing and rotating it slightly into the base or housing b External Regulators with Square Base Housing Only Install a new O Ring between the regulator and the mounting bracket Set the mounting bracket into position c Secure the regulator in base with the original retaining ring or screws Be careful not to dent or damage the body of the regulator as operating performance can be affected Heassemble any parts removed in step 3 5B 21 Section 5B EFI Fuel System 8 Reconnect the negative battery cable 9 Recheck regulated system pressure at fuel rail test valve Fuel Filter EFI engines use a high volume high pressure 10 15 micron in line fuel filter Figure 5B 32 In Line Fuel Filter Service Fuel filter replacement is recommended every 1500 hours of operation or more frequently under extremely dusty or dirty conditions Use only the specified filter and install it according to the directional arrows Do not use a substitute filter as operating performance and safety can be affected Relieve system pressure through the safety valve in the fuel rail before s
22. the gauge reading and listen for escaping air at the carburetor intake exhaust outlet and crankcase breather Check your test results against the following table Section 3 Troubleshooting Leakdown Test Results Air escaping from crankcase breather sesssesnnnnserrrsrnrrernnreerrrrnrnnene Defective rings or worn cylinder Air escaping from exhaust system sees Defective exhaust valve Air escaping from carburetor enne Defective intake valve Gauge reading in low green zone cccccseeeeceseseeeeeeeeeseeeeessaeeeeens Piston rings and cylinder in good condition Gauge reading in moderate yellow zone esses Engine is still usable but there is some wear present Customer should start planning for overhaul or replacement Gauge reading in high red zone Rings and or cylinder have considerable wear Engine should be reconditioned or replaced 3 5 Section 3 Troubleshooting 3 6 CH18 745 Section 4 Air Cleaner and Air Intake System Air Cleaners General Most engines are equipped with a replaceable high density paper air cleaner element surrounded by an oiled foam precleaner and housed under a flat outer cover This is typically referred to as the standard air cleaner assembly See Figures 4 1 and 4 4 Some engines utilize a heavy duty style air cleaner as shown in Figure 4 12 Figure 4 1 Standard Air Cl
23. 10 for lifter preparation bleed down procedures 2 Apply camshaft lubricant Kohler Part No 25 357 14 S to the bottom surface of each lifter See Figure 11 34 Lubricate the hydraulic lifters and the lifter bores in the crankcase with engine oil 11 10 H Figure 11 36 Match Numbers on Cylinder Barrel and Head Figure 11 37 Intake Valve Seal Location Valve Stem Seals These engines use valve stem seals on the intake valves and occasionally on the exhaust valves Always use a new seal whenever the valve is removed or if the seal is deteriorated or damaged in any way Never reuse an old seal Figure 11 37 Assemble Cylinder Heads Prior to installation lubricate all components with engine oil paying particular attention to the lip of the valve stem seal valve stems and valve guides Install the following items in the order listed below using a valve spring compressor See Figures 11 38 and 11 39 e Intake and exhaust valves e Valve spring caps Valve springs Valve spring retainers e Valve spring keepers Section 11 Reassembly Figure 11 39 Installing Valves with Valve Spring Compressor Install Cylinder Heads NOTE Oylinder heads must be attached with the original type of mounting hardware using either hex flange screws or mounting studs with nuts and washers The heads are machined differently for studs than for Screws so the fastening method cannot be altered unless the heads ar
24. 408 1 MOUNTING e THRU MOUNTING HOLES HOLE A 7 250 Figure 1 5 Typical Engine Dimensions CH EFI Series with Heavy Duty Air Cleaner 1 7 Section 1 Safety and General Information General Specifications Power 3600 RPM corrected to SAE J1995 ORO a R E a enc cs cetemne be E acces 13 4 kW 18 HP CORZO ED M E 14 9 kW 20 HP S eo 16 4 kW 22 HP Sim S KEE D MIT 18 4 kW 25 HP E t Her 19 4 kW 26 HP erc ETE UND 20 1 kW 27 HP ORTA 20 9 kW 28 HP Peak Torque CHIS 2200 EE 44 4 N m 32 8 ft Ib Sia 2600 RPM 44 2 N m 32 6 ft Ib 0H22 23 2200 EE 51 7 N m 38 2 ft Ib OH25 OH730 s 9 2900 E 54 1 N m 39 9 ft Ib GHZ6 2800 AP My EE 54 2 N m 40 0 ft Ib CH740 3000RPM 57 9 N m 42 7 ft Ib OHTA5 G Medis ecc 60 7 N m 44 8 ft Ib Bore Qual Xe IM LN ePm 77 mm 3 03 in H22 23 67 EE 80 mm 3 15 in OH25 RER OH790X749 E 83 mm 3 27 in SPOKE NT TERN 67 mm 2 64 in Displacement CHTS GH20 GH22 624 EE 624 cc 38 cu in Qu E Cr 674 cc 41 cu in GH29 GHZ6 GA bein e EE 725 cc 44 cu in Compression Ratio CHTS GH20 RE 8 5 1 20H25 OH26 OH790 74D EE 9 0 1 Dry Weight GAS CH20 eL ULc
25. Air Cleaner Element S P Ch Air Cleaner Bracket e Air Cleaner Base Air Cleaner Bracket coupe me EE Air Cleaner Base Gasket Intake z Y GE 7 rNing Intake Manifold ON Gasket T o X Screw Manifold Plastic Intake Manifold Figure 4 8 Exploded View of Standard Air Intake System Components 4 3 Section 4 Air Cleaner and Air Intake System Rear Mounting Screws nY Figure 4 10 Rear Mounting Screws Used with Plastic Intake Manifold L E Figure 4 11 Breather Tube Air Cleaner Components Whenever the air cleaner cover is removed or the paper element or precleaner are serviced check the following 4 4 Air Cleaner Element Cover and Seal Make sure element cover is not bent or damaged Make sure the wing nut and seal are in place to ensure the element is sealed against leakage Air Cleaner Base Make sure the base is secured tightly to the carburetor and not cracked or damaged Breather Tube Make sure the tube is attached to both the air cleaner base and the breather cover NOTE Damaged worn or loose air cleaner components can allow unfiltered air into the engine causing premature wear and failure Tighten or replace all loose or damaged components Complete Disassembly and Reassembly Standard Type If the base plate on the standard type has to be removed proceed as follows 1 Remove air cleaner components as described earlier 2 R
26. Bleeding the Lifters To prevent a possible bent push rod or broken rocker arm it is important to bleed any excess oil out of the lifters before they are installed 1 Cut a 50 75 mm 2 3 in piece from the end of an old push rod and chuck it in a drill press 2 Lay arag or shop towel on the table of the drill press and place the lifter open end up on the towel 3 Lower the chucked push rod until it contacts the plunger in the lifter Slowly pump the plunger two or three times to force the oil out of the feed hole in the side of the lifter Closure Plate Assembly Inspection 10 Inspect the oil seal in the closure plate and remove it if it is worn or damaged Refer to Install Closure Plate Oil Seal in Section 11 for new oil seal installation Inspect the main bearing surface for wear or damage refer to Section 1 Specifications Tolerances and Special Torque Values Replace the closure plate assembly if required Governor Gear Assembly Inspection Inspect the governor gear teeth Replace the gear if it is worn chipped or if any teeth are missing Inspect the governor weights They should move freely in the governor gear 10 11 Section 10 Inspection and Reconditioning Disassembly The governor gear must be replaced once it is removed from the closure plate NOTE The governor gear is held onto the shaft by small molded tabs in the gear When the gear is removed from the shaft these tab
27. Clean dirt and debris from exterior of carburetor 4 Remove the four screws holding the two carburetor halves together Carefully lift the upper body off the carburetor body and disconnect choke linkage Figure 5 6 Carburetor Detail 5 Hold the carburetor upper body so that the float assembly hangs vertically and rests lightly against the fuel inlet needle The fuel inlet needle should be fully seated but the needle tip should not be depressed See Figure 5 7 NOTE The fuel inlet needle tip is spring loaded Make sure the float assembly rests against the fuel inlet needle without depressing the tip 6 The correct float height adjustment is 22 mm 0 86 in measured from the float bottom to the air horn casting Adjust the float height by carefully bending the tab NOTE Be sure to measure from the casting surface not the rubber gasket surface 7 If proper float height adjustment cannot be achieved check to see if the fuel inlet needle is dirty obstructed or worn Remove the brass screw and float assembly to remove the fuel inlet needle Section 5 Fuel System and Governor Figure 5 7 Carburetor Float Adjustment 8 Once the proper float height is obtained carefully lower the carburetor air horn assembly onto the carburetor body connecting the choke linkage Install the four screws Torque the screws to 1 7 N m 15 in Ib See Figure 5 6 9 Connect the fuel line 10 Install the breather hose a
28. For example a starting problem could be caused by an empty fuel tank Some general common causes of engine troubles are listed below Use these to locate the causing factors Refer to the specific section s within this service manual for more detailed information Engine Cranks But Will Not Start Empty fuel tank Fuel shut off valve closed Poor fuel dirt or water in the fuel system Clogged fuel line opark plug lead s disconnected Key switch or kill switch in off position Faulty spark plugs Faulty ignition module s SMART SPARK malfunction applicable models 10 Carburetor solenoid malfunction OOo LO Los Ies 11 Diode in wiring harness failed in open circuit mode 12 Vacuum fuel pump malfunction or oil in vacuum hose 13 Vacuum hose to fuel pump leaking cracked 14 Battery connected backwards Engine Starts But Does Not Keep Running 1 Restricted fuel tank cap vent 2 Poorfuel dirt or water in the fuel system 3 Faulty or misadjusted choke or throttle controls 4 Loose wires or connections that short the kill terminal of ignition module to ground Faulty cylinder head gasket Faulty carburetor Vacuum fuel pump malfunction or oil in vacuum hose 8 Leaking cracked vacuum hose to fuel pump 9 Intake system leak N OO 10 Diode in wiring harness failed in open circuit mode Engine Starts Hard C SOOO Ud QU ae ae D e PTO drive is engaged Dirt or water in the fuel sy
29. Hold the pulley firmly and untie the slipknot Allow the pulley to rotate slowly as the spring tension is released 5 When all spring tension on the starter pulley is released remove the rope from the pulley 6 Tie a single knot in one end of the new rope 7 Rotate the pulley counterclockwise when viewed from pawl side of pulley until the spring is tight approximately 6 full turns of pulley 8 Rotate the pulley clockwise until the rope hole in the pulley is aligned with the rope guide bushing of the starter housing NOTE Do not allow the pulley spring to unwind Enlist the aid of a helper if necessary or use a C clamp to hold the pulley in position 9 Insert the new rope through the rope hole in the starter pulley and the rope guide bushing of the housing See Figure 7 3 7 2 Rope Guide Bushing Rope Hole Figure 7 3 Installing Rope 10 11 12 Tie a slipknot approximately 12 in from the free end of rope Hold the pulley firmly and allow it to rotate slowly until the slipknot reaches the guide bushing of the housing Slip the handle and rope retainer onto the rope Tie a single knot at the end of the rope Install the rope retainer into the starter handle Untie the slipknot and pull on the handle until the rope is fully extended Slowly retract the rope into the starter When the spring is properly tensioned the rope will retract fully and the handle will stop against the starter hou
30. If detrimental wear or damage is found in any of the parts the carburetor should be replaced Figure 5A 7 5A 5 Section 5A LPG Fuel Systems LPG Carburetor Reassembly Impco Carburetor 1 Slide the venturi into the carburetor body aligning the position mark made prior to removal Correctly installed the discharge holes should not be visible from the top 2 Secure with the venturi retaining screw Torque the screw to 4 0 N m 36 in Ib 3 Install a new adapter gasket and mount the air cleaner adapter onto the carburetor with the four screws Torque the screws to 4 0 N m 36 in Ib 4 Install a new carburetor gasket onto the intake manifold adapter followed by the carburetor Install and finger tighten the mounting fasteners 5 Connect the Z end of the throttle linkage and the dampening spring to the throttle clamp bracket on the throttle shaft Attach the opposite end of linkage and spring to the governor lever NOTE The clamp brackets and stop collar mounted on the throttle shaft should still be in their original positions See Figure 5A 2 and not require any readjustment resetting Continue with steps 6 and 7 If the mounted position of any one of these was affected or changed it will be necessary to check and reset the position of each before proceeding Follow the complete instructions listed after step 7 then continue with steps 6 and 7 6 Manually move the governor lever toward the carbu
31. O Ring style cover with integral spacers 9 9 N m 88 in Ib Figure 11 85 Valve Cover Fastener Torque Sequence NOTE Fastener 2 may secure fuel pump bracket on earlier models Figure 11 86 Tightening Valve Cover Screws Install Air Cleaner Assembly Hefer to Section 4 for air cleaner reassembly procedure 1 Attach the rubber breather hose to the breather cover Connect the fuel inlet line to the carburetor and secure with a clamp See Figure 11 87 Section 11 Reassembly 3 Secure the air cleaner base and bracket using the hex flange screws Position the bracket with the hole toward the breather hose Be careful not to drop screws into the carburetor If a rear air cleaner bracket is used install the two M5 screws through the rear of the base Torque the three M6 screws to 6 2 7 3 N m 55 65 in Ib and the two rear M5 mounting screws when applicable to 4 0 N m 35 in Ib See Figures 11 90 and 11 91 Figure 11 87 Connecting Fuel Inlet Line 2 Position a new gasket and the air cleaner base while carefully pulling the loose end of the rubber breather hose through the base until properly seated collars sealed against each side of base See Figure 11 88 Figure 11 88 Pulling Breather Hose through Base NOTE Route the fuel line in the contour as shown in Figure 11 89 to avoid restriction Some Models DI Figure 11 91 Tightening Rear Base Bracket Screws 4 Instal
32. O Rings Refer to the parts manual for the correct kit number Fuel Shut off Solenoid Most carburetors are equipped with a fuel shut off solenoid The solenoid is attached in place of the fixed main jet screw on the flywheel side of the carburetor See Figure 5 3 The solenoid has a spring loaded pin that retracts when 12 volts is applied to the lead allowing fuel flow through the main jet Section 5 Fuel System and Governor When current is removed the pin extends blocking the main fuel jet and preventing fuel from entering the carburetor y Fuel Shut off Solenoid ecd Figure 5 3 Fuel Shut off Solenoid Below is a simple test made with the engine off that can determine if the solenoid is functioning properly 1 Shut off fuel and remove the solenoid from the carburetor When the solenoid is loosened and removed gas will leak out of the carburetor Have a container ready to catch the fuel 2 Wipe the tip of the solenoid with a shop towel or blow it off with compressed air to remove any remaining fuel Take the solenoid to a location with good ventilation and no fuel vapors present You will also need a 12 volt power source that can be switched on and off 3 Besure the power source is switched off Connect the positive power source lead to the red lead of the solenoid Connect the negative power source lead to the solenoid bracket 4 Turn the power source on and observe the pin in the center of the sol
33. Replace stator 1 Make sure lights are not burned out 1 Replace burned out lights 2 Disconnect the lighting lead from the wiring 2 f voltage is 15 volts or more stator is OK harness Check for loose connections or shorts in wiring harness With engine running at 3000 RPM measure No voltage from lighting lead to ground using an If voltage is less than 15 volts test stator using Lights AC voltmeter an ohmmeter Test 3 3 With engine stopped measure the resistance 3 If resistance is approximately 0 4 ohms of stator from lighting lead to ground using an stator is OK ohmmeter If resistance is 0 ohms stator is shorted Replace stator If resistance is infinity ohms stator or lighting lead is open Replace stator 8 21 Section 8 Electrical System and Components Electric Starting Motors Some engines in this series use inertia drive starting motors while most use solenoid shift starters The inertia drive types are covered first and the solenoid shift types following Starting Motor Precautions NOTE Do not crank the engine continuously for more than 10 seconds at a time If the engine does not start allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn out the starter motor NOTE If the engine develops sufficient speed to disengage the starter but does not keep running a false start the engine rotation must be allowed to come to a complete stop
34. Replace the brush holder in the frame and place the brushes in the brush holder Reinstall the springs 8 28 Starter Service Every 500 hours of operation or annually whichever comes first solenoid shift starters must be disassembled cleaned and relubricated Apply starter lubricant Kohler Part No 52 357 02 S to the lever and shaft Failure to do so could result in an accumulation of dirt or debris that might prevent the engine from starting and could cause damage to the starter or the flywheel Service may be necessary more frequently under dusty or dirty conditions Starter Reassembly 1 Insert the rear stop collar on the armature shaft 2 Place the retainer in the groove on the armature shaft NOTE Always use a new retainer Tighten the retainer in the groove to secure 3 Fit the front stop collar over the shaft and bring the front and the rear stop collars together over the retainer Using two pairs of pliers apply even force to the two collars until they snap over the retainer and nest into one another 4 Reassemble the remaining components of the starter in reverse order from disassembly Delco Remy Starters Figure 8 40 Completed Delco Remy Starter Starter Disassembly 1 Remove the hex nut and disconnect the positive brush lead bracket from the solenoid terminal 2 Remove the three screws securing the solenoid to the starter See Figure 8 41 Section 8 Electrical System and Components
35. Rotate the pulley clockwise 2 full turns This will ensure the spring is disengaged from the starter housing 6 Hold the pulley in the starter housing Invert the pulley housing so the pulley is away from your face and away from others in the area 7 Rotate the pulley slightly from side to side and carefully separate the pulley from the housing See Figure 7 6 If the pulley and the housing do not separate easily the spring could be engaged in the starter housing or there is still tension on the spring Return the pulley to the housing and repeat step 5 before separating the pulley and housing Housing Figure 7 6 Removing Pulley from Housing 7 3 Section 7 Retractable Starter 8 Note the position of the spring and keeper assembly in the pulley See Figure 7 7 Remove the spring and keeper assembly from the pulley as a package A WARNING Spring Under Tension Do not remove the spring from the keeper Severe personal injury could result from the sudden uncoiling of the spring Rope Hole Figure 7 7 Position of Spring and Keeper in Pulley Inspection and Service 1 Carefully inspect the rope pawls housing center screw and other components for wear or damage 2 Replace all worn or damaged components Use only genuine Kohler replacement parts as specified in the Parts Manual All components shown in Figure 7 1 are available as service parts Do not use nonstandard parts 3 Do not attempt to r
36. S A 1PTP 2428 B 6 A LI 4
37. See Figure 9 71 Figure 9 71 Pulling Governor Cross Shaft Remove Flywheel End Oil Seal 1 Remove oil seal from crankcase See Figure 9 72 Figure 9 72 Removing Oil Seal CH18 745 Section 10 Inspection and Reconditioning This section covers the operation inspection and repair reconditioning of major internal engine components The following components are not covered in this section They are covered in sections of their own Air Cleaner Section 4 Carburetor amp External Governor Section 5 Ignition Charging amp Electric Starter Section 8 Clean all parts thoroughly Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Use an aerosol gasket remove paint stripper or lacquer thinner to remove any old sealant Apply the solvent allow time for it to work and then brush the surface with a brass wire brush After the old sealant is removed clean the surface with isopropyl alcohol lacquer thinner or aerosol electrical contact cleaner Do not scrape the surfaces
38. Shaft M 5 975 6 012 mm 0 2352 0 2367 in Max Wear ER eE Ee 5 962 mm 0 2347 in 8 mm Shaft wd LEE 7 949 8 000 mm 0 3129 3149 in Max Wear Bn DE 7 936 mm 0 3124 in Governor Gear Shaft to Governor Gear Running Clearance 0 015 0 140 mm 0 0006 0 0055 in Governor Gear Shaft O D P mE E eee eer eee ee eee nee ener 5 990 6 000 mm 0 2358 0 2362 in Max Wear I a eee eee ec ee nr Rm 5 977 mm 0 2353 in Governor Lever Nut Toroue nennen 6 8 N m 60 in Ib Ignition Spark Plug Type Champion or Equivalent sssssssss RC12YC or Platinum 3071 Park le EE e EE 0 76 mm 0 030 in Spark Plug EIB 24 4 29 8 N m 18 22 ft Ib Ignition Module AIF Gab EE 0 28 0 33 mm 0 011 0 013 in Ignition Module Fastener Torque c cscccccceeseeeeeeceesaeeeeeeseeeeeeeeseeeaees 4 0 6 2 N m 35 55 in Ib Speed Sensor Air Gap EFI engines ccccccccessseeeeeseeseeeeeseaseeeeeees 1 250 1 750 mm 0 049 0 068 in Section 1 Safety and General Information Muffler Muffler Retaining Nut Toroue 24 4 N m 216 in Ib Oil Filter zie eO DT 10 4 12 7 N m 90 110 in Ib Oil Cooler Oil Cooler Adapter Nipple Torque cccccsscceceeeeeeeceseeeeeeeeeseeeeeesanes 27 N m 20 ft Ib Piston Piston Rings and Piston Pin Piston to Piston Pin Running Clearance sssessesneeseesnrrrrrersrerrrresse 0 006 0 017 mm 0 0002 0 0007 i
39. Starter A WARNING Spring Under Tension Retractable starters contain a powerful recoil spring that is under tension Always wear safety goggles when servicing retractable starters and carefully follow instructions in this section for relieving spring tension To Remove Starter 1 Remove the five hex flange screws securing the starter to the blower housing Hex e Starter Housing Flange Screws 02 N Handle with SEK Rope Retainer 2 Remove the starter To Install Starter 1 Install the retractable starter onto the blower housing leaving the five hex flange screws slightly loose 2 Pull the starter handle out until the pawls engage Pulley in the drive cup Hold the handle in this position m i Springs and tighten the screws securely JS Pawls Brake Washer f O Rope Replacement Brake Spring Pts Pawl Retainer The rope can be replaced without complete starter disassembly 3 Plain Washer 1 Removethe starter from the blower housing Center Screw ges 2 Pull the rope out approximately 12 in and tie a uio temporary slip knot in it to keep it from retracting We Drive Cup into the starter See Figure 7 2 Figure 7 1 Retractable Starter Exploded View 7 1 Section 7 Retractable Starter Slipknot Knot Rope Retainer Figure 7 2 Removing Starter Handle 3 Remove the rope retainer from inside the starter handle Untie the single knot and remove the rope retainer and handle 4
40. Temperatures high enough to do this are created by friction which is usually attributed to improper lubrication and or overheating of the engine Normally very little wear takes place in the piston boss piston pin area If the original piston and connecting rod can be reused after new rings are installed the original pin can also be reused but new piston pin retainers are required The piston pin is included as part of the piston assembly if the pin boss in the piston or the pin are worn or damaged a new piston assembly is required Ring failure is usually indicated by excessive oil consumption and blue exhaust smoke When rings fail oil is allowed to enter the combustion chamber where it is burned along with the fuel High oil consumption can also occur when the piston ring end gap is incorrect because the ring cannot properly conform to the cylinder wall under this condition Oil control is also lost when ring gaps are not staggered during installation When cylinder temperatures get too high lacquer and varnish collect on pistons causing rings to stick which results in rapid wear A worn ring usually takes on a shiny or bright appearance Scratches on rings and pistons are caused by abrasive material such as carbon dirt or pieces of hard metal Overheated or Deteriorated Oil Figure 10 8 Common Types of Piston Damage Section 10 Inspection and Reconditioning Detonation damage occurs when a portion of the fuel c
41. The first style is easily identified by its metal case with large 35 pin connector block and also as MA 1 7 See Figure 5B 1 The second and third styles have plastic cases but are smaller in overall size These have either a 24 pin or 32 pin connector block and identified as MSE 1 0 or MSE 1 1 respectively See Figures 5B 2 and 5B 3 Basic function and operating control remains the same between the three however due to differences in the internal circuitry as well as the wiring harness none of the ECU s are interchangeable Certain individual service troubleshooting procedures also apply where applicable they are covered individually as 35 Pin MA 1 7 Metal Cased ECU 24 Pin MSE 1 0 Plastic Cased ECU or 32 Pin MSE 1 1 Plastic Cased ECU General The ECU is the brain or central processing computer of the entire EFI fuel ignition management system During operation sensors continuously gather data which is relayed through the wiring harness to input circuits within the ECU Signals to the ECU include ignition on off crankshaft position and speed RPM throttle position oil temperature exhaust oxygen levels and battery voltage The ECU compares the input signals to the programmed maps in its memory to determine the appropriate fuel and spark requirements for the immediate operating conditions The ECU then sends output signals to set the injector duration and ignition timing The ECU continually performs a diagn
42. Valve 6 Contact Button 2 Primary Valve Seat 7 Primary Valve Lever 3 Primary Chamber 8 Primary Lever Spring 4 Primary Diaphragm 9 Primary Pressure 5 Primary Diaphragm Spring Adjustment Figure 5A 21 Primary Chamber Section 5A LPG Fuel Systems Nikki Regulator Secondary Chamber See Figure 5A 22 The secondary chamber further reduces the fuel pressure from the 29 kPa 4 psi of the primary chamber to near 0 kPa 0 psi pressure to prevent excessive fuel flow to the carburetor Fuel enters the secondary chamber 13 through the clearance between the secondary valve 11 and the valve seat 12 While the engine is operating and fuel is being drawn from the secondary chamber the secondary diaphragm 14 is raised by atmospheric pressure simultaneously lifting the secondary valve lever 16 opening the secondary valve 11 allowing fuel to flow When the engine is running at idle there may not be enough vacuum created in the carburetor venturi to overcome the tension of the secondary diaphragm spring 15 and the secondary diaphragm cannot open the valve Under those conditions the idle adjusting screw 18 and balance spring 19 are used to apply just enough pressure on the diaphragm 14 to maintain sufficient fuel flow for idle operation The vacuum lock off mechanism is located in the secondary chamber When the engine is running manifold vacuum above the diaphragm 17 draws it up so the secondary valve
43. absolutely required by fault code diagnosis or throttle shaft service If the TPS is loosened or repositioned the appropriate TPS Initialization Procedure pages 5B 8 5B 10 must be performed to reestablish the baseline relationship between the ECU and the TPS 5B Service The TPS is a sealed non serviceable assembly If diagnosis indicates a bad sensor complete replacement is necessary If a blink code indicates a problem with the TPS it can be tested as follows 1 Counting the number of turns back out the idle speed adjusting screw counterclockwise until 1 Throttle Valve Shaft the throttle plates can be closed completely 2 Resistor Track 3 Wiper Arm w Wiper 2 Disconnect the main harness connector from the 4 Electrical Connection ECU but leave the TPS mounted to the throttle body manifold Figure 5B 6 Throttle Position Sensor Details 3 Connect the ohmmeter leads as follows General See chart on pages 5B 28 5B 31 or 5B 32 The throttle position sensor TPS is used to indicate throttle plate angle to the ECU Since the throttle by way of the governor reacts to engine load the angle of the throttle plate is directly proportional to the load on the engine 35 Pin MA 1 7 Metal Cased ECU Red positive ohmmeter lead to 12 pin terminal and Black negative ohmmeter lead to 27 pin terminal 24 Pin MSE 1 0 Plastic Cased ECU Red positive ohmmeter lead to 8 pin terminal
44. activate and continuity should exist circuit made between the 30 and 87 terminals Repeat the test several times If at any time the relay fails to activate the circuit replace the relay Fuel Injectors Figure 5B 16 Style 1 Fuel Injector Figure 5B 17 Style 2 Fuel Injector General The fuel injectors mount into the intake manifold and the fuel rail attaches to them at the top end Replaceable O Rings on both ends of the injector prevent external fuel leakage and also insulate it from heat and vibration A special clip connects each injector to the fuel rail retaining it in place Section 5B EFI Fuel System When the key switch is on and the relay is closed the Service fuel rail is pressurized and voltage is present at the Injector problems typically fall into three general injector At the proper instant the ECU completes the categories electrical dirty clogged or leakage An ground circuit energizing the injector The valve needle electrical problem usually causes one or both of the in the injector is opened electromagnetically and the injectors to stop functioning Several methods may be pressure in the fuel rail forces fuel down through the used to check if the injectors are operating inside The director plate at the tip of the injector see inset contains a series of calibrated openings which 1 With the engine running at idle feel for directs the fuel into the manifold in a cone shaped operational vi
45. and other sources of ignition away from the area Follow the cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent 1 2 Carbon Monoxide can cause severe nausea fainting or death Do not operate engine in closed or confined area Lethal Exhaust Gases Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled Avoid inhaling exhaust fumes and never run the engine in a closed building or confined area AA WARNING Uncoiling Spring can cause severe injury Wear safety goggles or face protection when servicing retractable starter Spring Under Tension Retractable starters contain a powerful recoil spring that is under tension Always wear safety goggles when servicing retractable starters and carefully follow instructions in the Retractable Starter Section 7 for relieving spring tension Explosive Gas can cause fires and severe acid burns Charge battery only in a well ventilated area Keep sources of ignition away Explosive Gas Batteries produce explosive hydrogen gas while being charged To prevent a fire or explosion charge batteries only in well ventilated areas Keep sparks open flames and other sources of ignition away from the battery at all times Keep batteries out of the reach of chilaren Remove all jewelry when servicing batteries Before dis
46. any other light is displayed in either of the tests the rectifier regulator is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure 4 Amp Unregulated Rectifiers 1 Connectthe tester ground lead with spring clamp to the body of rectifier being tested 2 Connect the red tester lead to the B center terminal of the rectifier and the two black tester leads to the two AC outside terminals See Figure 8 28 Section 8 Electrical System and Components 4 Press the TEST button until a click is heard and then release See Figure 8 23 Momentarily either the HIGH LOW or SHORT light will flash a If the HIGH light flashes on off the part is good and may be used b If any other light is displayed the rectifier is faulty and should not be used NOTE A flashing LOW light can also occur as a result of an inadequate ground lead connection Make certain connection location Figure 8 28 is clean and clamp is secure 3 Plug the tester into a 110 volt AC outlet and turn on the power switch The POWER light should be illuminated and one of the four status lights may be on as well See Figure 8 22 This does not represent the condition of the part Rectifier Regulator Flywheel Stator Ammeter Battery Figure 8 29 Connections for Testing Char
47. base of the terminal connectors with GE Novaguard G661 Kohler Part No 8 Rotate the flywheel back and forth checking for 25 357 11 S or Fel Pro Lubri Sel dielectric clearance between the magnet and ignition compound The beads should overlap modules Make sure the magnet does not strike between the terminals to form a solid bridge the modules Check the gap with a feeler gauge of compound See Figure 11 52 Do not put and readjust if necessary Final Air Gap any compound inside the terminals 0 280 0 330 mm 0 011 0 013 in The 24 584 15 S ignition modules have a Install Intake Manifold separator barrier between the terminals On these 1 Install the intake manifold and new gaskets or modules seal the base of the terminals but it is O Rings plastic manifold with wiring harness not necessary to have overlapping beads of attached to the cylinder heads Slide any wiring sealant between the connections harness clips onto the appropriate bolts before installing Make sure the gaskets are in the proper orientation Torque the four screws in two stages first to 7 4 N m 66 in Ib then to 9 9 N m 88 in Ib using the sequence shown in Figure 11 51 Figure 11 51 Intake Manifold Torque Sequence Figure 11 53 Routing of Wiring Harness 2 Connect the kill lead to the tab terminal on standard ignition modules See Figure 11 54 11 15 Section 11 Reassembly Figure 11 54 Connecting Kill Leads on Standard Fig
48. brush holder assembly down into Brush Holder Assembly place around the commutator install the positive brush lead grommet in the cutout of a Carefully unhook the retaining caps from over the frame See Figure 8 66 each of the brush assemblies Do not lose the springs 8 35 Section 8 Electrical System and Components Figure 8 66 Installing Brush Holder Assembly using Tool with Extension 11 Install the end cap onto the armature and frame aligning the thin raised rib in the end cap with the corresponding slot in the grommet of the positive brush lead 12 Install the two thru bolts and the two brush holder mounting screws Torque the thru bolts to 5 6 9 0 N m 49 79 in Ib Torque the brush holder mounting screws to 2 5 3 3 N m 22 29 in Ib See Figures 8 67 and 8 68 Figure 8 67 Torquing Thru Bolts 8 36 Figure 8 68 Torquing Brush Holder Screws 13 Hook the plunger behind the upper end of the drive lever and install the spring into the solenoid Insert the three mounting screws through the holes in the drive end cap Use these to hold the solenoid gasket in position then mount the solenoid Torque the screws to 4 0 6 0 N m 35 53 in Ib 14 Connect the positive brush lead bracket to the solenoid and secure with the hex nut Torque the nut to 8 11 N m 71 97 in Ib Do not overtighten See Figure 8 69 Figure 8 69 Positive Brush Lead Connection CH18 745 Section 9
49. car engines 6 1 Section 6 Lubrication System Checking Oil Level The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized Check oil BEFORE EACH USE as follows 1 Make sure the engine is stopped level and is cool so the oil has had time to drain into the sump 2 Clean the area around the dipstick before removing it This will help to keep dirt grass clippings etc out of the engine 3 Remove the dipstick wipe oil off Reinsert the dipstick into the tube until fully seated See Figure 6 2 Oil Fill Cap Figure 6 2 Location of Oil Fill Cap and Dipstick 4 Remove dipstick and check oil level The level should be between the F and L marks If low add oil of the proper type up to the F mark Reinstall oil fill cap and dipstick Operating Range Figure 6 3 Oil Level Marks on Dipstick 6 2 NOTE To prevent extensive engine wear or damage always maintain the proper oil level in the crankcase Never operate the engine with the oil level below the L mark or above the F mark on the dipstick Changing Oil and Oil Filter Changing Oil Change the oil after every 100 hours of operation more frequently under severe conditions Refill with service class SG SH SJ or higher oil as specified in the Viscosity Grades table on page 6 1 Change the oil while the engine is still warm The oil will flow more freely and carry away more
50. clockwise see Figure 8 33 The resistance against the center screw will tell you when the retaining ring has popped out of the groove in the armature shaft Screw Clockwise to Remove Retaining Ring 6 Remove the drive components from the armature shaft paying attention to the sequence If the splines are dirty clean them with solvent The splines should have a light film of lubricant Relubricate as necessary with Kohler bendix starter lubricant Part No 52 357 01 S Reinstall or replace the drive components assembling them in the reverse order they were removed Retaining Ring Installation 1 Position the retaining ring in the groove in one of the inner halves Assemble the other half over the top and slide on the outer collar Be certain the drive components are installed in correct sequence onto the armature shaft Slip the tool over the end of the armature shaft so the retaining ring inside is resting on the end of the shaft Hold the tool with one hand exerting slight pressure toward the starter Tap the top of the tool with a hammer until you feel the retaining ring snap into the groove Disassemble and remove the tool Squeeze the retaining ring with a pliers to compress it into the groove Assemble the inner halves with the larger cavity around the spring retainer see Figure 8 34 Slide the collar over them and thread the center screw in until resistance is felt Figure 8 34 Assembling Lar
51. flange screws securing each valve cover Note the position of any attached brackets or lifting straps 2 Remove the valve covers valve cover gaskets or O Rings and any brackets or lifting straps Note which side of the engine has the oil fill and or fuel pump valve cover See Figure 9 40 Figure 9 40 Removing Valve Covers Section 9 Disassembly Remove Ignition Modules 3 Leave the wiring harness attached to the 1 Disconnect the lead s from each ignition manifold module See Figure 9 41 Modules for non SMART SPARK ignition systems have only one Aluminum kill lead Intake Manifold Aa ct Figure 9 41 Disconnecting Leads from Ignition Modules 2 Rotate the flywheel so the magnet is away from the modules 3 Remove the mounting screws and ignition modules Note the position of ignition modules Figure 9 42 Position of SMART SPARK Ignition Module Remove Intake Manifold 1 Remove the four hex flange screws securing the intake manifold to the cylinder heads Note which screws hold the wiring clamps 2 Remove the intake manifold and the intake manifold gaskets aluminum intake manifolds or O Rings plastic intake manifolds See Figure 9 43 9 11 Section 9 Disassembly Remove Spark Plugs 1 Remove the spark plug from each cylinder head Figure 9 45 Removing Spark Plugs Remove Cylinder Heads and Hydraulic Lifters NOTE Oylinder heads are retained using either hex 9 12
52. gasket D on the new filter Figure 6 5 Removing Oil Fill Cap GE 7 Install the new oil filter to the filter adapter Hand tighten the filter clockwise until the rubber gasket contacts the adapter then tighten the filter an additional 2 3 1 turn Changing Oil Filter Replace the oil filter at least every other oil change every 200 hours of operation Always use a genuine Kohler oil filter Change the filter as follows See Figure 6 6 8 Remove the oil fill cap and fill the engine with the proper oil to the F mark on the dipstick Always check the oil level with the dipstick before adding more oil 9 Reinstall the oil fill cap and dipstick 10 Start the engine and check for oil leaks Stop the engine correct any leaks and allow a minute for the oil to drain down then recheck the level on the dipstick Cil Drain Plug Figure 6 6 Oil Drain Plug and Oil Filter engine with oil cooler 6 3 Section 6 Lubrication System Service Oil Cooler Some engines are equipped with an oil cooler One style of oil cooler mounts on the engine crankcase and has the oil filter on it The other style of oil cooler is mounted on the blower housing separate from the oil filter See Figure 6 7 Crankcase Mounted Oil Cooler Blower Housing Mounted Oil oda Figure 6 7 Oil Coolers Inspect and clean the oil cooler every 100 hours of operation more frequently under severe conditions In order to
53. ground Lamp missing 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 29 to lamp open or shorted 3 Vehicle Wiring Harness Related a Broken or shorted wire in harness Power lead to MIL open or shorted 4 ECU Related a Circuit controlling lamp damaged 5B 41 Section 5B EFI Fuel System Code 56 32 Pin MSE 1 1 Plastic Cased ECU only Source Fuel pump relay circuit open shorted to ground or shorted to battery Fuel pump ignition coils and fuel injectors will not function because the fuel pump relay circuit is either open shorted to ground or may be on continuously if shorted to battery Expected Engine Response Engine will not run or fuel pump will continue to run when switch is off Explanation Possible Causes 1 Fuel Pump Relay Related a Bad fuel pump relay Primary side open or shorted 2 Fuel Pump Related a Fuel pump open or shorted internally 3 Engine Wiring Harness Related a Fuel pump fuse F1 open b Broken or shorted wire in harness ECU pin 28 to fuel pump relay pin 86 Ignition switch to fuel pump relay pin 85 4 ECU Related a Circuit controlling fuel pump relay damaged 5B 42 Code 61 Source Explanation Denotes the end of fault codes If signaled first no other fault codes are present Troubleshooting Flow Chart The following flow chart on page 5B 43 provides an alternative method of troubleshooting
54. heavy black lead see Figure 5B 5 Viewing the connector as shown dual aligning rails on top test the resistance between the terminals indicated A reading of 750 1000 Q should again be obtained Dual Aligning Rails Corresponds To 3 Metal Cased ECU or 10 Plastic Cased ECU In Main Connector Plastic Cased ECU In Main Connector Test Terminals Figure 5B 5 Speed Sensor Connector 7 a Ifthe resistance is incorrect remove the screw securing the sensor to the mounting bracket and replace the sensor b If the resistance in step 5 was incorrect but the resistance of the sensor alone was correct test the main harness circuits between the sensor connector terminals and the corresponding pin terminals in the main connector Correct any observed problem reconnect the sensor and perform step 5 again Section 5B EFI Fuel System Throttle Position Sensor TPS Mounted on the throttle body intake manifold and operated directly off the end of the throttle shaft the TPS works like a rheostat varying the voltage signal to the ECU in direct correlation to the angle of the throttle plate This signal along with the other sensor signals is processed by the ECU and compared to the internal preprogrammed maps to determine the required fuel and ignition settings for the amount of load The correct position of the TPS is established and set at the factory Do not loosen the TPS or alter the mounting position unless
55. lint free cloth Do not use emery cloth If the commutator is badly worn or grooved turn it down on a lathe or replace the armature Starter Reassembly 1 Place the thrust washer if so equipped over the drive shaft of the armature 8 26 Insert the armature into the starter frame Make sure the magnets are closer to the drive shaft end of armature The magnets will hold the armature inside the frame Install the drive end cap over the drive shaft Make sure the match marks on the end cap and starter frame are aligned See Figure 8 37 Figure 8 37 Starter Assembly Match Marks For Style A Commutator End Caps Install the brush holder tool to keep the brushes in the pockets of the commutator end cap 5 Align the match marks on the commutator end cap and the starter frame Hold the drive end and the commutator end caps firmly to the starter frame Remove the brush holder tool For Style B Commutator End Caps If the brush assembly is not being replaced position the brushes in their pockets in the carrier Move them to the retracted position and install carton staples to retain them See Figure 8 38 5 Align the terminal stud block with the notch in the starter frame and slide the brush carrier assembly into the frame The commutator will push the carton staples out as the brush assembly is installed Position the end cap over the brush assembly so the holes for the thru bolts are aligned wi
56. lobes of the camshaft for wear or damage See Section 1 for minimum lift specifications Inspect the cam gear for badly worn chipped or missing teeth Replacement of the camshaft will be necessary if any of these conditions exist Crankshaft Inspection and Service Inspect the gear teeth of the crankshaft If the teeth are badly worn chipped or some are missing replacement of the crankshaft will be necessary 10 1 Section 10 Inspection and Reconditioning Inspect the crankshaft bearing surfaces for scoring grooving etc Some engines have bearing inserts in the crankshaft bore of the closure plate and or crankcase Do not replace bearings unless they show signs of damage or are out of running clearance specifications If the crankshaft turns easily and noiselessly and there is no evidence of scoring grooving etc on the races or bearing surfaces the bearings can be reused Inspect the crankshaft keyways If they are worn or chipped replacement of the crankshaft will be necessary Inspect the crankpin for score marks or metallic pickup Slight score marks can be cleaned with crocus cloth soaked in oil If the wear limits as stated in Specifications and Tolerances are exceeded it will be necessary to either replace the crankshaft or regrind the crankpin to 0 25 mm 0 010 in undersize If reground a 0 25 mm 0 010 in undersize connecting rod big end must then be used to achieve proper running clearance Measure
57. lock If the engine has a metal screen it will be installed later Figure 11 31 Installing Plastic Grass Screen 11 9 Section 11 Reassembly Install Supports for the Metal Grass Screen 1 lf a metal grass screen is used with threaded individual supports install a spacer washer on the external threads Apply blue Loctite No 242 removable onto the threads Install the four supports as shown in Figure 11 32 Figure 11 34 Applying Camshaft Lubricant to Bottom of Lifters 3 Note the mark or tag identifying the hydraulic lifters as either intake or exhaust and cylinder 1 or cylinder 2 Install the hydraulic lifters into their i appropriate location in the crankcase Do not use Figure 11 32 Installing Supports for Metal Grass a magnet See Figure 11 35 Screen NOTE Hydraulic lifters should always be 2 Tighten the supports with a torque wrench to installed in the same position as before 9 9 N m 88 in Ib See Figure 11 33 The grass disassembly The exhaust lifters are screen will be installed to the supports after the located on the output shaft side of the blower housing is in place engine while the intake lifters are located on the fan side of the engine The cylinder numbers are embossed on the top of the crankcase and each cylinder head See Figure 11 36 Figure 11 33 Torquing Supports for Metal Screen Some Models Install Hydraulic Lifters 1 See Servicing Hydraulic Lifters in Section
58. marks the old piston may be reused 3 Remove the old rings and clean up the grooves Never reuse old rings 4 Before installing the new rings on the piston place the top two rings each in turn in its running area in the cylinder bore and check the end gap See Figure 10 9 Compare the ring gap to the specifications listed in Section 1 Figure 10 9 Measuring Piston Ring End Gap 5 After installing the new compression top and middle rings on the piston check the piston to ring side clearance Compare the clearance to specifications listed in Section 1 If the side clearance is greater than specified a new piston must be used Refer to Figure 10 10 10 10 Figure 10 10 Measuring Piston Ring Side Clearance Install New Piston Rings To install new piston rings proceed as follows NOTE Rings must be installed correctly Ring installation instructions are usually included with new ring sets Follow instructions carefully Use a piston ring expander to install rings see Figure 10 11 Install the bottom oil control ring first and the top compression ring last Refer to Figure 10 12 Piston Ring Piston Ring M gt Expander m Figure 10 11 Installing Piston Rings Piston Ring End Hae Identification Mark Piston CA Va T ge Up M E Oil Control Ring Three piece Expander Figure 10 12 Piston Ring Installation 1 Oil Control Ring Bottom Groove Install the
59. misfiring loss of speed and power linkage to ensure choke is operating properly governor hunting or excessive Low idle fuel mixture is improperly adjusted Adjust low idle fuel throttle opening needle some models Float level is set too high Separate carburetor air horn from carburetor body adjust float according to steps 4 and 5 on page 5 7 Dirt under the fuel inlet needle Remove needle clean needle and seat and blow with compressed air Bowl vent or air bleeds plugged Remove low idle fuel adjusting needle Clean vent ports and air bleeds Blow out all passages with compressed air Leaky cracked or damaged float Submerge float to check for leaks Engine runs lean indicated by Low idle fuel mixture is improperly adjusted Adjust low idle fuel misfiring loss of speed and power needle some models governor hunting or excessive Float level is set too low Separate carburetor air horn from throttle opening carburetor body adjust float according to steps 4 and 5 on page 9 7 Idle holes plugged dirt in fuel delivery channels Remove low idle fuel adjusting needle Clean main fuel jet and all passages blow out with compressed air 4 Fuelleaks from carburetor Float level set too high See Remedy 2d Dirt under fuel inlet needle See Remedy 2e Bowl vents plugged Blow out with compressed air Carburetor bowl gasket leaks Replace gasket 5 4 Troubleshooting Checklist When the engine starts hard runs ro
60. open shorted to ground or shorted to battery Explanation Injector 2 is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run very poorly with only one cylinder functioning Possible Causes 1 Injector Related a Injector coil shorted or opened Section 5B EFI Fuel System 2 Engine Wiring Harness Related a b Broken or shorted wire in harness ECU pin 15 to injector pin 2 ECU pin 28 to fuel pump relay pin 86 Note after key off then key on code 56 would be set also Fuel pump relay pin 87 to injector pin 1 Opened main fuse F1 3 Fuel Pump Relay Related a Bad fuel pump relay Primary side functional but pin 30 to pin 87 remains open Primary side pin 85 to pin 86 is open or shorted during engine operation Note after key off then key on code 56 would be set also 4 ECU Related a Circuit controlling injector 2 damaged b Circuit controlling fuel pump relay damaged Code 55 32 Pin MSE 1 1 Plastic Cased ECU only Source MIL Diagnostic lamp circuit open shorted to ground or shorted to battery Explanation MIL is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Response Engine will run normally if no other errors are present Possible Causes 1 MIL diagnostic lamp Related a b MIL element opened or element shorted to
61. plug if necessary NOTE Do not clean spark plug in a machine using abrasive grit Some grit could remain in the spark plug and enter the engine causing extensive wear and damage 3 Check the gap using a wire feeler gauge Adjust the gap to 0 76 mm 0 030 in by carefully bending the ground electrode See Figure 8 1 Wire Gauge Spark Plug Ground Electrode 0 76 mm 0 030 in Gap Figure 8 1 Servicing Spark Plug 4 Reinstall the spark plug into the cylinder head and torque to 24 4 29 8 N m 18 22 ft Ib Inspection Inspect each spark plug as it is removed from the cylinder head The deposits on the tip are an indication of the general condition of the piston rings valves and carburetor Normal and fouled plugs are shown in the following photos 8 1 Section 8 Electrical System and Components Normal A plug taken from an engine operating under normal conditions will have light tan or gray colored deposits If the center electrode is not worn a plug in this condition could be set to the proper gap and reused Carbon Fouled Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich carburetion weak ignition or poor compression Worn On a worn plug the center electrode will be rounded and the gap will be greater than the specified gap Replace a worn spark plug immediately 8 2 Wet Fouled A wet plug is caused by excess fue
62. regulator Testing may be performed with the rectifier regulator mounted or loose The figures show the part removed from the engine for clarity Repeat the applicable test procedure two or three times to determine the condition of the part 15 Amp Rectifier Regulators 1 Connect the tester ground lead with spring clamp to the body of the rectifier regulator being tested 2 Connect the tester red lead to the B terminal of the rectifier regulator and the two black tester leads to the two AC terminals See Figure 8 21 Figure 8 21 Section 8 Electrical System and Components 3 Plugthe tester into a 110 volt AC outlet supply 20 25 Amp Rectifier Regulators and turn on the power switch See Figure 8 22 1 Connect the single lead adapter in between the The POWER light should be illuminated and B center terminal of rectifier regulator being one of the four status lights may be on as well tested and the squared single end of the tandem This does not represent the condition of the part adapter lead See Figure 8 24 Figure 8 22 Figure 8 24 4 Press the TEST button until a click is heard 2 Connect the tester ground lead with spring and then release See Figure 8 23 Momentarily clamp to the body of the rectifier regulator one of the four lights will illuminate indicating the condition of the part 3 Connect the red lead and one of the black leads to the pair of terminals on the open end of the tandem adapter lead
63. screw 87 and pin 15 Resistance should be 4 15 Q attaching the rectifier regulator ground lead for each circuit Remove the blower housing 5B 16 10 11 12 13 14 15 16 Thoroughly clean the area around and including the throttle body manifold and the injectors Disconnect the throttle linkage and damper spring from the throttle lever Disconnect the TPS lead from the harness Hemove the manifold mounting bolts and separate the throttle body manifold from the engine leaving the TPS fuel rail air baffle injectors and line connections intact Discard the old gaskets Position the manifold assembly over an appropriate container and turn the key switch on to activate the fuel pump and pressurize the system Do not turn switch to start position If either injector exhibits leakage of more than two to four drops per minute from the tip or shows any sign of leakage around the outer shell turn the ignition switch off and replace injector as follows Depressurize the fuel system following the procedure in the fuel warning on page 5B 2 Hemove the two fuel rail mounting screws Clean any dirt accumulation from the sealing mounting area of the faulty injector s and disconnect the electrical connector s Pull the retaining clip off the top of the injector s and remove from manifold Reverse the appropriate procedures to install the new injector s and reassemble the engine Use new O Rings a
64. screw is torqued to specifications Figure 11 28 Carefully Align Keyway to Key NOTE Make sure the flywheel key is installed properly in the keyway The flywheel can become cracked or damaged if the key is not properly installed 1 Install the woodruff key into the keyway of the crankshaft Make sure that the key is properly seated and parallel with the shaft taper 2 Install the flywheel onto the crankshaft being careful not to shift the woodruff key See Figure 11 28 3 Install the hex flange screw and washer 4 Use a flywheel strap wrench or holding tool to hold the flywheel Torque the hex flange screw securing the flywheel to the crankshaft to 66 4 N m 49 ft Ib See Figure 11 29 Figure 11 29 Installing and Torquing Flywheel Fastener Section 11 Reassembly Install Flywheel Fan 1 Install the fan onto the flywheel using the four hex flange screws NOTE Position the ears located at rear perimeter of the fan in the recesses of the flywheel See Figure 11 30 Figure 11 30 Installing Fan on Flywheel 2 Torque the screws to 9 9 N m 88 in Ib Install Plastic Grass Screen 1 Ifthe engine has a plastic grass screen snap the screen onto the fan See Figure 11 31 Due to the possibility of damaging the posts during removal install the retainers on different posts from which they were removed Start the retainers by hand then push them down with a 13 mm 1 2 socket until they
65. spark plug hole Install the spark plugs but do not connect the plug leads Crank the engine two or three revolutions On equipment with an EFI engine disconnect the battery or use a battery minder to keep the battery charged during storage Store the engine in a clean dry place 1 5 Section 1 Safety and General Information 14 77 4 582 i 60 00 AIR CLEANER 7 362 COVER REMOVAL FUE FILTER 15 70 4 142 04 92 10 5 5972 618 OIL FILTER REMOVAL HO 468 28 ON SOME MODELS 18 436 20 28 HP 456 58 S 17 976 113 20 18 HP 4 457 20 28 HP MECHANICAL Cat tc ets FUEL PUNVP 3 998 DIPSTICK 18 HP OIL FILL 9 525 375 SQ KEYWAY 20 28 HP eX OIL DRAIN PLUG 39 00 8 350 250 3 8 NPaTa INCH 4 SO KEYWAY 3 504 18 HP MOUNTING HOLE A 4 J LA Y 28 58 36 51 Wr 1 3 1 125 1 438 A r 18 HP 20 28 HP LA Wi E 287 09 i Wels Pie ie CS PT 155 58 4 ren mne Za E 025 SS i E dE 5 B 18 UNF 2B 6 125 m 38 10 1 500 DEEP d da 7 Se SUE HOT O L COOLER 7 15 20 UNF 28 4 00 1 iene Se 38 10 1 500 DEEP p i57 s Ser amp Benes x Bei 3 937 504 a Q 30 MOUNT ING 1 Sa age S e SURF ACE S x MOUNTING HOLE A Ted CS L_ I Jeers B B 16 UNC 2B INCH 17 00 0 669 DEEP Cala aa 142 88 5 6251 B C 11 888 _ IET 5m C vounge 7 25
66. specifications proceed to Step 6 6 Check the temperature sensor circuits input ground from the main harness connector to the corresponding terminal in the sensor plug for continuity damage etc 35 Pin MA 1 7 Metal Cased ECU Pin circuits 14 and 27 1 Connection Cable 5 Contact Element 2 Disc Spring 6 Sensor Housing 24 Pin MSE 1 0 Plastic Cased ECU Pin 3 Ceramic Support Tube 7 Active Ceramic Sensor circuits 6 and 4 4 Protective Sleeve 8 Protective Tube Figure 5B 12 Cutaway of Oxygen Sensor 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 6 and 4 The oxygen sensor can function only after being heated by exhaust temperatures to a minimum of Oxygen Sensor 375 C 709 F A cold oxygen sensor will require approximately 1 2 minutes at moderate engine load to warm sufficiently to generate a voltage signal Proper grounding is also critical The oxygen sensor grounds through the metal shell so a good solid unbroken ground path back through the exhaust system components engine and wiring harness is required Any disruption or break in the ground circuit can affect the output signal and trigger misleading fault codes Keep that in mind when doing any troubleshooting associated with the oxygen sensor The oxygen sensor can also be contaminated by leaded fuel certain RTV and or other silicone compounds carburetor cleaners etc Use only those products indicated as O Sensor Safe
67. terminal lead into the center position of the rectifier regulator plug and connect the plug to the rectifier regulator See Figures 11 69 and 11 70 11 19 Section 11 Reassembly b s Blower Housing Mounting Location Figure 11 71 Reinstalling SAM Module Install Electric Starter Motor 1 Install the starter motor using the two hex flange screws See Figure 11 72 Some inertia drive starters have a pinion cover and spacers on the starter bolts 2 Torque the two hex flange screws to 15 3 N m 135 in Ib Figure 11 72 Installing Electric Starter Motor 11 20 3 On models with a solenoid shift starter connect the leads to the solenoid See Figure 11 73 Figure 11 73 Connecting Leads to Starting Motor NOTE If the engine uses a side mount muffler on the starter side be sure to tie the wires close to the starter to avoid contact with hot exhaust parts Install Fuel Pump A WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel system Gasoline is extremely flammable and its vapors can explode if ignited Keep sparks and other sources of ignition away from the engine 1 Install the pulse style fuel pump and lines as an assembly Connect the pulse line to the crankcase vacuum fitting or the valve cover whichever source is used NOTE Pulse style fuel pumps may be made of metal or plastic See Figure 11 74 lfa new fuel pump is being installed make sure the ori
68. the ECU It is sealed to prevent damage to internal components Warranty is void if the case is opened or tampered with in any way All operating and control functions within the ECU are preset No internal servicing or readjustment may be performed If a problem is encountered and you determine the ECU to be faulty contact your source of supply Do not replace the ECU without factory authorization The relationship between the ECU and the throttle position sensor TPS is very critical to proper system operation If the TPS or ECU is changed or the mounting position of the TPS is altered the applicable TPS Initialization Procedure see pages 5B 8 or 5B 9 must be performed to restore the synchronization Engine Speed Sensor i E i E 9 d Si Di J 2 Ir Figure 5B 4 Engine Speed Sensor 5B 5 Section 5B EFI Fuel System General The engine speed sensor is essential to engine operation constantly monitoring the rotational speed RPM of the crankshaft A ferromagnetic 60 tooth ring gear with two consecutive teeth missing is mounted on the flywheel The inductive speed sensor is mounted 1 5 0 25 mm 0 059 0 010 in away from the ring gear During rotation an AC voltage pulse is created within the sensor for each passing tooth The ECU calculates engine speed from the time interval between the consecutive pulses The two tooth gap creates an interrupted input signal corresponding to specific crankshaft po
69. the crankpin for size taper and out of round NOTE If the crankpin is reground visually check to ensure that the fillet blends smoothly with the crankpin surface See Figure 10 1 High Point from Fillet Intersections The Fillet Must Blend Smoothly with the Bearing 45 Journal Surface Minimum Completely Smooth Figure 10 1 Crankpin Fillets The connecting rod journal can be ground one size under When grinding a crankshaft grinding stone deposits can get caught in the oil passages which could cause severe engine damage Removing the crankpin plug when the crankshaft is ground provides easy access for removing any grinding deposits that may collect in the oil passages Use the following procedure to remove and replace the plug 10 2 Procedure to Remove Crankshaft Plug 1 Drill a 3 16 hole through the plug in the crankshaft 2 Thread a 3 4 or 1 long self tapping screw with a flat washer into the drilled hole The flat washer must be large enough to seat against the shoulder of the plug bore See Figure 10 2 3 Tighten the self tapping screw until it draws the plug out of the crankshaft Procedure to Install New Plug 1 Useasingle cylinder camshaft pin Kohler Part No 47 380 09 S as a driver and tap the plug into the plug bore until it seats at the bottom of the bore Make sure the plug is tapped in evenly to prevent leakage Self Tapping Screw Flat Washer Crankshaft Figure 10 2 Removing Cr
70. the male and female terminals If any connections do not feel snug disconnect the lead lightly pinch the female terminal with a pliers and recheck the fit 7 When the integrity of all connections has been verified repeat the spark test Test 2 a lf a strong steady spark is now present both sides on a twin your problem should be corrected Go to step 4 of Test 5 b If there is still a spark problem perform all of Test 5 Test 5 Test the SAM 1 Trace the red power source lead from the SAM to the harness connection Separate the connector and connect the red lead of a DC voltmeter to the harness terminal Trace the ground lead from the SAM black on singles green on twins to the grounding screw Connect the black voltmeter lead to the eyelet terminal of the ground lead or the ground screw bolt Check the voltage with the key switch in both the START and RUN positions A minimum of 7 25 volts must be present a If correct voltage is not measured connect black voltmeter lead directly to the negative post of the battery and test voltage again in both key positions If correct voltage is now indicated check the ground circuit connections If the ground screw bolt or any other fasteners in the ground circuit are black oxide coated replace them with zinc plated silver colored fasteners b If correct voltage is still not indicated check the harness connector terminal for a good connection and cri
71. use of gasket remover solvent paint remover is recommended 1 If using the gasket or sealant type cover prepare the sealing surfaces of the cylinder head and cover as directed in Service Bulletin 252 Refer to Section 2 for approved sealants Always use fresh sealant using outdated sealant could result in leakage With O Ring type covers make sure the sealing surfaces are clean 2 Make sure there are no nicks or burrs on the sealing surfaces 3 Forcovers requiring RTV sealant apply a 1 5 mm 1 16 in bead to the sealing surface of both cylinder heads install a new valve cover gasket on each then apply a second bead of sealant on the top surface of the gaskets For O Ring type covers install a new O Ring in the groove of the covers Do not use gaskets or RTV sealant 4 Locate the cover with the oil fill neck on the same side as removed and install the lifting strap in the original position With O Ring type covers position the cover on the cylinder head If loose spacers were used insert a spacer in each of the screw holes On both types install the four hex flange screws in each cover and finger tighten 5 Torque the valve cover fasteners to the proper specification using the sequence shown in Figure 11 85 11 26 Gasket RTV style cover 3 4 N m 30 in Ib Black O Ring style cover with shoulder screws 5 6 N m 50 in Ib with screws and spacers 9 9 N m 88 in Ib Brown
72. 0 421 01 16 575 302 58 11 913 3 626 a r 14 7 582 ALTERNATE OIL FILL LOCATION 470 86 18 538 SOLENOID SHIFT STARTER 4X 10 30 I 406 THRU MOUNTING HOLES ENGINE SPARK ADVANCE MODULE STANDARD S Dimensions in millimeters Inch equivalents shown in LIFTING SIRAP PILOT 177 80 7 006 77 lO gt 14 JNC 2B INCH 21 00 0 B27 DEEF 1965 85 7 7500 B C Figure 1 4 Typical Engine Dimensions CH Series with Standard Flat Air Cleaner 1 6 Section 1 Safety and General Information Dimensions in millimeters Inch equivalents shown in 441 45 17 380 o 17 00 M meme E Dr D PE 5 000 9 016 BU DO mmm 80 00 i 3 00 3 156 2 382 312 9 118 i 2 319 de SPARK PLUG i zg i M e ALTERNATE OI P FILL LOCATION IGNITION COIlL N daB eacus 184 SPARK PLUG 672 00 26 457 ENS ID SHIFT STARTER 5 5e2 3 62 G ENGINE OIL FILTER Y REMOVAL ae GE Ee 4X 010 30 L
73. 000 000000000900 0 Section 5B EFI Fuel System hr i cri SO 35 Sani is oan di paprity Perey d adatti mpi oi pense ning 21415 impar 2 di agy drj ban oq ars pr wd s p und pam gt rus paper g 98 H poanbzu st drip Eatspac e pem si of dip e p B JON apr rer aot ue i Pia A LII OSTIA HL soap mpqiar H LLL aL LS aiv ey buius o4 passiv JI SONS vIQ 3 310N NhnO9 3135 HOLJ3NNO2 T cel F LEE JL osups JOSU8S 03395 3NION3 C c Wong PE Z WO123 NI 8O123PNI ipd E L apos pedals p e en voL 9 d m ha rly e pueg sud s orsa ap Dutt Six TE al b l SAME eu a Sd PUNO prs WEE simam LU GN psi se OLY umdo spii a d Zi DATA el L T Fp Uog Gdl 901 9 JOBEXZJ 9077 bt S Ume VO auuoo Sy Uess ucgsod auong ayl zl XE ei in CIE m T Ad ln aD Eos Buus Den E yum of G apg 015 sBEgaa Bugeraco jeunes 11 zx M m es E ei qed up peum susqo 0g Ajemeurxcdddk Jo Juzrpred E Aba 3p perm eq ugi 037 eu nord e 8 a Qc amp jguondg dui weosspuouny gy QJAZ E eq ues p duae soppy uorbunjiey D m Ee LUTE LEI Yi PST E aq g aig Ce pues sui ssimiosuse pasde m L Ln Burquega Bump uongrsdo rg sur uinusun aq qur eB yon Geier sur unie gs umg c fuimus an gde pe zu apu Ope z po me ap usura E y eu po Seyi WSEAS umm E UE Erud Ed eu Odo ur Lu uet a JGpo9uJu023 ppa au won Agng sDEUE m sahud L ONOI VE Dean je pened srna sre e d Dm av HOLYJIONI N
74. 25 CH26 CH730 745 sss 0 94 mm 0 037 in Piston Thrust Face O D New CH18 CH20 CH22 624 ech 76 967 76 985 mm 3 0302 3 0309 in New GH22 23 674 ER 79 963 79 979 mm 3 1481 3 1488 in New CH25 CH26 CH Z20 245 82 986 mm 3 3194 in Max Wear Limit CH18 CH20 CH22 624 CC 76 840 mm 3 0252 in Max Wear Limit CH22 674 el 79 831 mm 3 1430 in Max Wear Limit CH25 CH26 CH730 745 sess 82 841 mm 3 3136 in Measure 6 mm 0 236 in above the bottom of the piston skirt at right angles to the piston pin 1 12 Section 1 Safety and General Information Piston Piston Rings and Piston Pin cont Piston Thrust Face to Cylinder Bore Running Clearance New CH18 CH20 CH22 624 ec 0 014 0 057 mm 0 0005 0 0022 in New GH22 23 674 CC EE 0 021 0 062 mm 0 0008 0 0024 in New CH25 CH26 CH 20 24 0 001 0 045 mm 0 039 0 0018 in Speed Control Bracket Segel el 7 3 10 7 N m 65 95 in Ib Starter Assembly Thru Bolt Torque UTE Johnson Electric Eaton Inertia Drive 4 5 5 7 N m 40 50 in Ib Nippondenso Solenoid huit 4 5 7 5 N m 40 84 in Ib Delco Remy Solenoid hm 5 6 9 0 N m 49 79 in lb Mounting Screw Torque AU 15 3 N m 135 in Ib Brush Holder Mounting Screw Torque Delco Remy e 2 5 3 3 N m 22 29 in lb Solenoid Starter Mounting Hardware Torque Nippondenso Start
75. 3 Hand tighten the filter until the rubber gasket contacts the adapter then tighten the filter an additional 2 3 1 turn See Figure 11 94 11 28 Section 11 Reassembly Prepare the Engine for Operation The engine is now completely reassembled Before starting or operating the engine be sure to do the following 1 Make sure all hardware is tightened securely 2 Make sure the oil drain plugs oil sentry pressure switch and a new oil filter are installed 3 Fill the crankcase with the correct amount weight and type of oil Refer to oil recommendations and procedures in the Safety and General Information and Lubrication System sections Figure 11 96 Reinstall the Dipstick in Tube 4 Adjust the carburetor idle fuel needle or idle speed adjusting screw as necessary Refer to Section 5 the Fuel System and Governor 6 Make sure the O Ring is in place then reinstall the oil fill cap on the valve cover See Figure 11 97 Testing the Engine It is recommended that the engine be operated on a test stand or bench prior to installation in the piece of equipment 1 Set the engine up on a test stand Install an oil pressure gauge Start the engine and check to be certain that oil pressure 20 psi or more is present Run the engine at idle for 2 3 minutes then 5 6 minutes more between idle and midrange Adjust the carburetor mixture settings as necessary as available Figure 11 97 Reinstalling Oil Fill C
76. 5 fb 45 nnd G7 ond systen volinge CA D PF the igattion amp w tch controls o powered clecult e lights horn It hk recommended that a relay be uted to Control the power 3 To prevent signal errars load clecults le born llght amp shall not be powered fron the EFT engin or wre chasis harness 4 amp resistive spark px with efther a resistive spark plug eee or boot must be used ts prevent electrical system ris Di Tt amp recommend thot the ECU mousing be mounted vertikale ett the wins bundle down or herizentelly with the wenther paul connector owe 6 14 ls recomended thot the U not be mounted Ki She engine But be attached Ht or isolator plate or or br cket that can keep the whrations wthn the EDU specs T when not in operation the battery sust moltai a minium system voltage of 7 volts with a current draw of Bat to matum the adaptie mancr y m During start the battery Aust maitni 7 volts minimum For the ECU operatione during crark Di hese catherwika zpecitled All ares ore LAW H Inductee pickup wires in ond ID nre to be a testen pair with 1 twist per inch Lk Dagrosis losp is to be a DV L b incondescent lamp 123 Normal Operotioral Vito ix J vnc Svaur With nu cold cranxing dc voltage oF TWalts 133 TPS conection shown is For counter cipckwise rotation a tee TPS Diockwise rotoioe requres svttching wires to TFS pins lke 5B 30 Section 5B EFI Fuel System 24 Pin MSE 1 0 Plastic Cased ECU Systems Functio
77. 8 Electrical System and Components 7 Install the backup washer followed by the rubber grommet into the matching recess of the drive end cap The molded recesses in the grommet should be out matching and aligned with those in the end cap See Figure 8 60 Figure 8 58 Installing Thrust Washer 4 Apply a small amount of oil to the bearing in the drive end cap and install the armature with the drive pinion Hs 5 Lubricate the fork end and center pivot of the Figure 8 60 Installing Backup Washer and drive lever with drive lubricant Kohler Part No Grommet 52 357 02 S Position the fork end into the space between the captured washer and the rear of the 8 Install the frame with the small notch forward pinion onto the armature and drive end cap Align the notch with the corresponding section in the rubber 6 Slide the armature into the drive end cap and at grommet Install the drain tube in the rear cutout the same time seat the drive lever into the if it was removed previously See Figure 8 61 housing NOTE Correctly installed the center pivot section of the drive lever will be flush or below the machined surface of the housing which receives the backup washer See Figure 8 59 Figure 8 61 Installing Frame and Drain Tube 9 Install the flat thrust washer onto the commutator end of the armature shaft See Figure 8 62 Figure 8 59 Installing Armature and Pivot Lever 8 34 Section 8 Electrical S
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79. 9 b If during the procedure with the engine running the MIL stays on continuously for more than 15 seconds turn off the ignition Then initiate the fault code sequence by doing three consecutive key on key off cycles leaving the key on in the last sequence each key on key off sequence must be less than 2 5 seconds long The fault detected must be corrected before the auto learn function can be re initiated The PC based diagnostic tool and software may be used to read out the fault code and assist with the troubleshooting and repair 5B 10 Engine Oil Temperature Sensor Figure 5B 10 Engine Oil Temperature Sensor General The engine oil temperature sensor Figure 5B 10 is used by the system to help determine fuel requirements for starting a cold engine needs more fuel than one at or near operating temperature Mounted in the oil filter adapter housing it has a temperature sensitive resistor that extends into the oil flow The resistance changes with oil temperature altering the voltage sent to the ECU Using a table stored in its memory the ECU correlates the voltage drop to a specific temperature Using the fuel delivery maps the ECU then knows how much fuel is required for starting at that temperature Service The temperature sensor is a sealed non serviceable assembly A faulty sensor must be replaced If a blink code indicates a problem with the temperature sensor it can be tested as foll
80. 9 17 1 Disconnect the fuel lines at the pump outlet and at the in line fuel filter 2 The fuel pump will be removed with the valve cover Refer to the valve cover removal procedure NL P Figure 9 18 Removing Control Bracket 9 5 Section 9 Disassembly Remove External Governor Controls 1 Loosen the hex flange nut and remove the governor lever from the cross shaft See Figure 9 22 Leave lever attached to the throttle linkage and lay assembly on the top of the crankcase Figure 9 19 Rear Air Cleaner Bracket Some Models 2 Markthe spring hole locations and disconnect the spring from the governor lever See Figure 9 20 Figure 9 22 Removing Governor Lever Remove Carburetor A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent Figure 9 20 Disconnecting Spring from Bracket 1 Disconnect the fuel shut off solenoid lead if so equipped 3 Remove the choke linkage from the choke actuator lever and carburetor See Figure 9 21 2 Remove the two carburetor mounting screws See Figure 9 23 Figure
81. 9 21 Disconnecting Choke Linkage from Actuator Lever Screws 9 6 Section 9 Disassembly 3 Remove the carburetor throttle linkage and Remove Electric Starter Motor governor lever as an assembly See Figure 9 24 1 Disconnect the leads from the starter 2 Remove the two hex flange screws See Figure 9 26 Figure 9 24 Removing Carburetor Assembly with Governor Lever Attached 4 Remove the carburetor gasket Figure 9 26 Removing Electric Starter Motor 5 f necessary the carburetor throttle linkage and 3 Remove the starter assembly and any spacers if governor lever can be separated Reattach the used bushings to the linkage following separation to avoid losing them Remove Outer Baffles and Blower Housing f Se 1 Disconnect the plug from the rectifier regulator on Remove Oil Sentry If So Equipped the blower housing See Figure 9 27 1 Disconnect the lead from the Oil Sentry switch 2 Remove the Oil Sentry switch from the breather cover See Figure 9 25 Figure 9 27 Disconnecting Plug from Rectifier Regulator et 2 Use the tip of the dipstick or a similar small flat Figure 9 25 Removing Oil Sentry Switch from tool to bend the locking tang then remove the B Breather Cover center lead from the terminal plug as shown in Figure 9 28 This will allow the blower housing to be removed without disturbing the wiring harness 9 7 Section 9 Disassembly Figure 9 28 Remove B Le
82. Cased ECU Check between terminal 87 and pin 22 for coil 1 Repeat the test between terminal 87 and pin 23 for coil 2 32 Pin MSE 1 1 Plastic Cased ECU Check between terminal 87 and pin 30 for coil 1 Repeat the test between terminal 87 and pin 31 for coil 2 A reading of 1 8 4 0 Q in each test indicates that the wiring and coil primary circuits are OK a If reading s are not within specified range check and clean connections and retest b If reading s are still not within the specified range test the coils separately from main harness as follows 1 Disconnect the red and black primary leads from the coil terminals 2 Connect an ohmmeter set on the Rx1 scale to the primary terminals Primary resistance should be 1 8 2 5 Q 3 Disconnect the secondary lead from the spark plug Connect an ohmmeter set on the Rx10K scale between the spark plug boot terminal and the red primary terminal Secondary resistance should be 13 000 17 500 Q 5B 18 4 Ifthe secondary resistance is not within the specified range unscrew the spark plug lead nut from the coil secondary tower and remove the plug lead Repeat step b 3 testing from the secondary tower terminal to the red primary terminal If resistance is now correct the coil is good but the spark plug lead is faulty replace the lead If step b 2 resistance was incorrect and or the secondary resistance is still incorrect the coil is faulty and needs
83. Components The typical liquid withdrawal LPG fuel system consists of the following components e LPG Fuel Tank Liquid Withdrawal Electric Lock Off Filter Assembly e Vaporizer e LPG Regulator Combination Primary Secondary Vacuum Lock Off e LPG Carburetor High Pressure Fuel Line s e Vacuum Line Fuel Line Vaporizer CENE Vacuum Line Lock Off Filter ke pr Assembly ri 3 P ue BE t Em tM TW LI eg LPG Regulator Figure 5A 1 5A 1 Section 5A LPG Fuel Systems Operation In a liquid withdrawal system the Liquefied Petroleum Gas LPG is released from the bottom of the supply tank under high pressure Upon opening the shut off valve on the tank liquid fuel travels out through the high pressure line to the electric lock off filter assembly The lock off opens internally when the key switch is turned on permitting filtered fuel to flow to the vaporizer The vaporizer is mounted in the flow of the discharged cooling air It absorbs heat from the cooling air and transfers it to the fuel changing the liquefied petroleum to a vapor or gaseous state while partially stepping down the fuel pressure The gas vapor flows under this decreased pressure to the regulator where it is further reduced to a usable regulated pressure The regulator activated by intake manifold vacuum controls fuel flow to the carburetor In the venturi of the carburetor the fuel vapor is mixed with incoming air fr
84. D New CH18 CH20 CH22 624 cc seeeseeeeeeeeeees 77 000 77 025 mm 3 0315 3 0325 in New GH22 23 674 EE 80 000 80 025 mm 3 1496 3 1506 in New CH25 CH26 CH730 745 eessseeeesseeeenen nenne 82 988 83 013 mm 3 2672 3 2682 in Max Wear Limit CH18 CH20 CH22 624 co 77 063 mm 3 0340 in Max Wear Limit CH22 23 IG 4cc 80 065 mm 3 1522 in Max Wear Limit CH25 CH26 CH730 745 sssuse 83 051 mm 3 2697 in Max OUO BOLD uo rire ed deae ii mre tt 0 12 mm 0 0047 in Max ANS Ce m ET 0 05 mm 0 0020 in 1 10 Section 1 Safety and General Information Cylinder Head Cylinder Head Fastener Torque Hex Flange Nut Torque in Two Stages ccccecseeeeeeeeeeeeeeeeeeeeaees initially to 16 9 N m 150 in Ib D finally to 33 9 N m 300 in Ib Head Bolt Torque in Two Stages eseeeeeeeeeeeeen initially to 22 6 N m 200 in Ib finally to 41 8 N m 370 in Ib Max EREM 0 076 mm 0 003 in Rocker Arm Screw Toroue nennen 11 3 N m 100 in Ib Fan Flywheel Fan Fastener TOrque ee 9 9 N m 88 in Ib Flywheel Retaining Screw Torque no0nnnnonnnnnenennnnnneennnnsennnnnnennenes 66 4 N m 49 ft Ib Governor Governor Cross Shaft to Crankcase Running Clearance OT ebat ee 0 013 0 075 mm 0 0005 0 0030 in OMIT OMAN eege been 0 025 0 126 mm 0 0009 0 0049 in Governor Cross Shaft O D 6 mm
85. DT m e SE 11 Code 21 Engine Speed Synchronization Code 22 Throttle Position Sensor TPS Code 23 Engine Control Unit ECU Code 31 Oxygen Sensor Code 32 Oxygen Sensor Code 33 Fuel System temporary adaptation factor Code 34 Fuel System permanent adaptation factor Code 42 Engine Cil Temperature Sensor Code 43 TPS Auto Learn Initialization Function Below Min Limit 32 Pin MSE 1 1 Plastic Cased ECU only Code 44 TPS Auto Learn Initialization Function Above Max Limit 32 Pin MSE 1 1 Plastic Cased ECU only Code 51 Injector 1 32 Pin MSE 1 1 Plastic Cased ECU only 5B 44 12 13 14 15 Code 52 Injector 2 32 Pin MSE 1 1 Plastic Cased ECU only Code 55 MIL Light 32 Pin MSE 1 1 Plastic Cased ECU only Code 56 Pump Relay 32 Pin MSE 1 1 Plastic Cased ECU only Code 61 End of Fault Blink Code Transmission Diagnostic Aid 3 RUN ON MIL remains on while engine is running Possible causes 1 3 Fault codes which turn on MIL when engine is running Code 21 Engine Speed Synchronization Code 22 Throttle Position Sensor TPS Code 23 Engine Control Unit ECU Code 31 Oxygen Sensor shorted Code 34 Fuel System permanent adaptation at limit Code 42 Engine Cil Temperature Sensor g Code 43 TPS Auto Learn Initialization Function Below Min Limit 32 Pin MSE 1 1 Plastic Cased EC
86. E Z Bend Control Cable Throttle Control Cable Kill Switch Adjusting Screw Dual Control High Speed Lever Stop Screw Do Not Remove High Speed Adjusting Screw High Speed Control Lever Figure 5 11 Governor Control Connections Electronic Governor General The electronic governor regulates engine speed at varying loads It consists of a governor control unit digital linear actuator and linkage P Governor Control Unit 5 Figure 5 13 Electronic Governor Assembly Digital Linear Actuator DLA Energizing the bi directional digital linear actuator coils in the proper sequence causes the threaded shaft to move out of or back into the rotor in precise linear ren increments When power is removed the actuator Figure 5 12 Electronic Governor Assembly shaft remains in position The DLA must initialize fully extend to move the throttle plate to the closed 1 Digital Linear Actuator position and partially open for starting Correct 2 Throttle Linkage adjustment of the DLA is critical to achieve the full 3 Linkage Spring range of throttle plate movement See Adjustment 4 Choke Linkage Procedure 5 Throttle Lever Adapter 5 12 Section 5 Fuel System and Governor Governor Control Unit GCU senses engine speed by Adjustment Procedure pulse voltage inputs from the ignition modules The The DLA must be in the fully retracted position during GCU regulates the engine speed by variable input
87. ECU Harness Related a ECU to harness connection problem 5B 38 Code 31 Source Fuel Mixture or Oxygen Sensor Explanation System too lean Oxygen sensor not sending expected voltage to ECU Expected Engine Response System operates under open loop control only Until fault is detected and registered by ECU engine will run rich if oxygen sensor is shorted to ground or lean if it is shorted to battery voltage After fault is detected performance can vary depending on cause If performance is pretty good the problem is probably with the oxygen sensor wiring or connectors If the engine is still running rich laboring short on power or lean popping or misfiring the fuel mixture is suspect probably incorrect TPS initialization or low fuel pressure Possible Causes 1 TPS Initialization Incorrect a Lean condition check oxygen sensor signal with VOA and see Oxygen Sensor section 2 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 3 Low Fuel Pressure 4 Oxygen Sensor Related a Sensor connector or wiring problem b Exhaust leak c Poor ground path to engine sensor is case grounded 5 Poor system ground from ECU to engine causing rich running while indicating lean Code 32 Source Oxygen Sensor Explanation No chan
88. Figure 9 50 Match Marks on Cylinder Barrel and Heads 9 13 Section 9 Disassembly Disassemble Cylinder Heads 3 Once the valve spring is compressed remove the 1 Remove the two hex flange screws rocker arm following items See Figures 9 53 and 9 54 pivots and rocker arms from the cylinder head See Figure 9 51 e Valve spring keepers e Valve spring retainers e Valve springs e Valve spring caps e Intake and exhaust valves mark position e Valve stem seals intake valve only Figure 9 51 Removing Rocker Arms 2 Compress the valve springs using a valve spring compressor See Figure 9 52 Figure 9 54 Intake Valve Seal Location NOTE These engines use valve stem seals on the intake valves Use a new seal whenever valve is removed or if the seal is deteriorated in any way Never reuse an old seal 4 Repeat the above procedure for the other cylinder head Do not interchange parts from one cylinder head to the other Remove Grass Screen and Fan 1 Small metal retainers are typically attached on three of the seven mounting posts for positive retention of the plastic grass screen Use a hook end tool next to the post and pull outward to separate each of the small metal retainers Then unsnap the fan from the remaining mounting posts See Figure 9 55 Figure 9 52 Removing Valves with Valve Spring Compressor Keepers Retainer Figure 9 53 Valve Train Components 9 14 Section 9 Disass
89. Functional Test The electric lock off can be easily tested to verify that it is functional Remove it from the system for testing Using a 12 volt power supply or battery connect one wire lead to the positive lead of power supply and touch remaining wire lead to negative lead of power supply When connection is made an audible click should be heard indicating the opening of the lock off While energized blow compressed air through it to determine if it is blocked or restricted Figure 5A 15 Figure 5A 16 Electric Lock Off Filter Assembly Filter Service The filter inside the lock off assembly should be replaced every 500 hours of operation or if it becomes blocked or restricted Cleaning of the filter element is not recommended Order a replacement filter element by the appropriate Kohler part number Vaporizer Assembly The outer surface of the vaporizer should be kept free of dirt and debris accumulation which will cause a loss of vaporization efficiency Visual inspection and necessary cleaning should be performed on a regular basis more frequently under dusty or dirty conditions The vaporizer should be disassembled cleaned and serviced using a rebuild kit every 1500 hours or if a problem is encountered Figure 5A 17 LPG Regulator The regulator controls both the pressure and flow of fuel within the LP system It is comprised of both a primary and secondary chamber which are dependent upon one ano
90. MT 5 Se g anui p easel nu l 1189 uo131uB i T I FI Ri EET m L l 3 B 1 2 DIL I LI III Bd yupds Le Spu1fn dm Appen TY ILR uid SE 5B 29 Ke uL T LA V Lh V See Genaral Mate IO he ye an Pe ee a 5 ell EFI Fuel System Section 5B Connector JI ER FUT D Battery S iPenmanent Ei Switched lor eon Et Saftey SZeltch 43 TRS amp Temp Ground EM Het Ligen 63 Hotere Tesp input T5 Spore A D Inout B TPS iaut Di WR Input is 10 YR Input 3 Hr Larios Input 12 Lmmhds Ground OF need Hk K Line ER TPS Supelv Woltoge ID Battery Ground 163 injector 1 Dutnut AEN 7 Dei vin 155 Ding Lasts veer Bit Tach Output ED Spore output EM ieee utp ou ga wh TFS set La instruction attached te engine block prar starder The sengor grounds te the engine via the mf Pla Ir ren Lesged genge is ued pin 12 is joren ground I asi Joint is weed grounding strap a required attached to ch zziz Attached to engi block opge to the rod General System Installation Motes D The ignition switch must polton a constunt voltage to circults 84 BH ond JI 2 as the Hey ik swept Fron Cup postion te prevent an ECU reset during starting B3 The voltoge an circuits B4 B5 JS and J i must remain f 02 volts GE each other r ess of syster current draw ta prevent differences between ootustor volteges elrcults 6 amp
91. OUOND TW 4 F wta UT FERUEI BIN MERES I auiDue 83 woy pare mod eqaou ELE LSA N Woy SU sanum peaj sous ue aad ol e Jamod eu pauco A pesnegAapu E IE pepuseu Dos si Buoy SD ai eon pausa ecd E gogo user LUE mj CL Ln seges uias pus 46 pur ep no sd UNS Safe SEE us SIS ESOU bb Jus gud oy a EJp Man UE S 10 Sep Jays USES pe ISS oun uiui vnu n pue r 1p P 65 pg sinas uo BE ayj z BU Buunp ra rn ed apuenigod ur qat EE ug use SE siis aursE g Lp pug og pg SINE OL abe gon ESO UE gemi youms Mogul ayy E GE ON KERGER ELSA KC KEEN SE D se ir d HOLIMS e is A134vV5 AH3LL vH Pi x T Hon iaiia se ei TX DAY gi modia omy A v 3LON gt 2 ORNICRPIOHO e 335 T D r i Gul O NnONO AN311vH 29 IT Te OLLIND Les c d c HOLIMS SH d o HK lt 2 Ca A P PPP ia d xD I Ge 5B 33 6 ON JON 1vH3N39 335 Section 5B EFI Fuel System Fuel System A WARNING Fuel System Under Pressure The fuel system operates under high pressure System pressure must be relieved through the test valve in the fuel rail prior to servicing or removing any fuel system components Do not smoke or work near heaters or other fire hazards Have a fire extinguisher handy and work only in a well ventilated area The function of the fuel system is to provide sufficient delivery of fuel at the system o
92. PARK PLUG Yes INSTALL IN LINE PRESSURE GAUGE AND KEY ON FUEL PRESSURE IN SPECIFICATION No REFER TO DIAGNOSTIC AID 8 FUEL SYSTEM ELECTRICAL DN e REFER TO DIAGNOSTIC AID 9 FUEL SYSTEM REFER TO DIAGNOSTIC AID 10 Yes BASE ENGINE Operate for an appropriate period of time based upon original fault codes Figure 5B 44 5B 43 Section 5B EFI Fuel System Flow Chart Diagnostic Aids Diagnostic Aid 1 SYSTEM POWER MIL does not illuminate when key is turned on Possible causes 1 2 3 4 8 9 Battery Main system fuse MIL light bulb burned out MIL electrical circuit problem 35 Pin MA 1 7 Metal Cased ECU Pin circuits 31 and 31A 24 Pin MSE 1 0 Plastic Cased ECU Pin circuits 19 and 84 32 Pin MSE 1 1 Plastic Cased ECU Pin circuits 29 and 84 Ignition switch Permanent ECU power circuit problem 35 Pin MA 1 7 Metal Cased ECU Pin circuit 16 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 1 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 1 Switched ECU power circuit problem 35 Pin MA 1 7 Metal Cased ECU Pin circuit 17 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 2 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 2 ECU grounds ECU Diagnostic Aid 2 FAULT CODES Refer to detailed fault code listing before flow chart and servicing information for the respective components P
93. Remove inner baffles and breather cover 15 Remove valve covers 16 Remove ignition modules 17 Remove intake manifold 18 Remove spark plugs oo oe ee e 19 Remove cylinder heads and hydraulic lifters 20 Remove grass screen and fan 21 Remove flywheel 22 Remove stator and backing plates 23 Remove closure plate assembly 24 Remove camshaft 25 Remove connecting rods with pistons and rings 26 Remove crankshaft 2 7 Remove governor cross shaft Disconnect Spark Plug Leads 1 Disconnect the leads from the spark plugs See Figure 9 1 NOTE Pull on boot only to prevent damage to spark plug lead Figure 9 1 Disconnect Both Spark Plug Leads Shut Off Fuel Supply Drain Oil from Crankcase and Remove Oil Filter 1 Remove the oil fill cap and dipstick and one of the oil drain plugs 9 1 Section 9 Disassembly 3 Remove and discard the oil filter See Figure 9 5 Figure 9 4 Removing Oil Drain Plug Figure 9 6 Removing Oil Filter Adapter Nipple 2 Allow ample time for the oil to drain from the crankcase and oil filter 9 2 Figure 9 7 Removing Oil Cooler 4 Anoil cooler is standard equipment on some models and an option on others It may be a cast aluminum housing part of the oil filter adapter or attached to the blower housing separated from the oil filter adapter If so equipped remove the adapter and the cooler See Figures 9 6 and 9 7 Remove Muffler 1 Remove t
94. U only h Code 44 TPS Auto Learn Initialization Function Above Max Limit 32 Pin MSE 1 1 Plastic Cased ECU only i Code 51 Injector 1 32 Pin MSE 1 1 Plastic Cased ECU only j Code 52 Injector 2 32 Pin MSE 1 1 Plastic Cased ECU only k Code 55 MIL Light 32 Pin MSE 1 1 Plastic Cased ECU only l Code 56 Pump Relay 32 Pin MSE 1 1 Plastic Cased ECU only MIL circuit grounded between light and ECU 35 Pin MA 1 7 Metal Cased ECU Pin circuit 31 24 Pin MSE 1 0 Plastic Cased ECU Pin circuit 19 32 Pin MSE 1 1 Plastic Cased ECU Pin circuit 29 ECU GK h NOTE MIL in Metal Cased ECU systems is an LED The MIL in Plastic Cased ECU systems must be a 1 4 watt incandescent lamp Section 5B EFI Fuel System Diagnostic Aid 4 SPEED SENSOR MIL does not Diagnostic Aid 7 IGNITION SYSTEM no spark turn off during cranking Indicates the ECU is not receiving a signal from the speed sensor Possible causes 1 Spark plug Possible causes 2 Plug wire 1 Speed sensor 3 Coil 2 Speed sensor circuit problem 4 Coil circuit s 35 Pin MA 1 7 Metal Cased ECU Pin circuits 35 Pin MA 1 7 Metal Cased ECU Circuits 1 3 and 21 19 40 40A 43 and relay 24 Pin MSE 1 0 Plastic Cased ECU Pin 24 Pin MSE 1 0 Plastic Cased ECU Circuits circuits 9 and 10 22 23 65 66 30 and relay 32 Pin MSE 1 1 Plastic Cased ECU Pin
95. Valve Guide Reamer Size Tele e B RE DENEN SE RE TM RU RO RUE 7 048 mm 0 2775 in O25 MMO EE 7 298 mm 0 2873 in Intake Valve Minimum EE 8 07 mm 0 3177 in Exhaust Valve Minimumi libanas L Eu ae ova 8 07 mm 0 3177 in Nominal Valve Seat Angle sseesssssseseseeeeeeeen nennen 45 General Torque Values Metric Fastener Torque Recommendations for Standard Applications Tightening Torque N m in Ib or 10 Property Class Noncritical Fasteners Into Aluminum Tightening Torque N m ft Ib or 10 Property Class Noncritical Fasteners Into Aluminum 33 9 25 61 0 45 94 9 70 Section 1 Safety and General Information English Fastener Torque Recommendations for Standard Applications Tightening Torque N m in Ib or 20 Bolts Screws Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners Into G3 Aluminum Grade 2 Grade 5 Grade 8 18 7 165 22 6 200 39 6 350 Torque Conversions N m in Ib x 0 113 N m ft Ib x 1 356 in lb Nrxm x 8 85 ft Ib N xm x 0 737 Section 1 Safety and General Information 1 16 CH18 745 Section 2 Special Tools Certain quality tools are designed to help you perform specific disassembly repair and reassembly procedures By using tools designed for the job you can service engines easier faster and safer In addition you ll increase your service capabilities and customer satisfacti
96. a Pin circuits 4 6 and or 4A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem 2 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pin circuits 4 6 and or 4A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem 5B 40 3 System Related a Engine is operating above the 176 C 350 F temperature sensor limit Code 43 and 44 32 Pin MSE 1 1 Plastic Cased ECU only Source TPS Auto Learn initialization function failed throttle angle out of learning range Explanation While performing the TPS Auto Learn function the measured throttle angle was not within acceptable limits Expected Engine Response MIL illuminated Engine will continue to run but not properly Upon restart TPS Auto Learn function will run again unless voltage to ECU disconnected to clear memory Possible Causes 1 TPS Related a TPS rotated on throttle shaft assembly beyond allowable range b TPS bad 2 Engine Wiring Harness Related a Broken or shorted wire in harness ECU pin 18 to TPS pin 1 ECU pin 4 to TPS pin 2 ECU pin 8 to TPS pin 3 3 Throttle Body Related a Throttle shaft inside TPS worn broken or damaged b Throttle plate loose or misaligned c Throttle plate bent or damaged allowing extra airflow past or restricting movement 4 ECU R
97. ad from Terminal Plug 3 The rectifier regulator does not have to be detached from the blower housing If the engine is equipped with SMART SPARK the SAM module should be removed from the cylinder baffle or blower housing See Figure 9 29 The module willing hang loose as part of the wiring harness Figure 9 29 Removing the Spark Advance Module Applicable Models 9 8 Remove the three each side hex flange screws securing the outer baffles Note the location of any lifting strap and position of the two short screws one each side on bottom for reassembly See Figure 9 30 Figure 9 31 Removing Outer Baffles 5 Remove the outer baffles on both sides See Figure 9 31 On engines equipped with a metal grass screen remove the screen before removing the blower housing See Figure 9 32 Plastic grass screens can be removed after the blower housing is removed Section 9 Disassembly Figure 9 32 Removing Metal Grass Screen Figure 9 34 Removing Fasteners Holding Baffle and Breather Cover 7 Remove the lower blower housing screw and washer securing the rectifier regulator ground 2 Remove both inner baffles See Figure 9 35 lead or grounding strap 8 Remove the remaining hex flange screws and detach the blower housing See Figure 9 33 9 Disconnect the plug from the key switch in the blower housing if engine is so equipped 3 Remove the two remaining screws holding the breather cover t
98. against the crankcase See Figure 11 2 Section 11 Reassembly ng Oil Seal Figure 11 4 Installing Governor Cross Shaft Hitch Pin 6 mm Shaft Figure 11 2 Installi Install Governor Cross Shaft 1 Lubricate the governor cross shaft bearing surfaces in the crankcase with engine oil 2 Slide the small lower washer onto the governor cross shaft and install the cross shaft from the inside of the crankcase 3 6mm Governor Shaft Install the plain washer and then insert the hitch pin into the smaller lower hole of the governor cross shaft See Figures 11 3 and 11 4 8 mm Governor Shaft Install the nylon washer onto the governor cross shaft then start the push on retaining ring Hold the cross shaft up in position place a 0 50 mm 0 020 in feeler gauge on top of the nylon washer and push the retaining ring down the shaft to secure Remove the feeler gauge which will have established the proper end play See Figures 11 5 and 11 6 Figure 11 6 Setting Governor Cross Shaft End Play 8 mm Shaft Install Crankshaft 1 Carefully slide the flywheel end of the crankshaft through the main bearing in the crankcase See Figure 11 7 Figure 11 3 Installing 6 mm Governor Cross Shaft 11 2 j l L E 2 i s j Figure 11 7 Installing Crankshaft Install Connecting Rods with Pistons and Rings NOTE The cylinders are numbered on the crankcase Make sure to install the piston con
99. age the stator 8 13 Section 8 Electrical System and Components 15 20 25 amp Regulated Charging System Oil Sentry Red Key Switch Panel pm Wire Ground Remote Light Oil Pressure Switch Biue Red Wire Red Wire White Wire X Oil Sentry Kill Green Yellow Wires A Spark Plug Connector 48 155 01 ua WP m Layout To Suit Kohler R Rectifier K Key Switch 25 099 04 V M Magneto Cy Connector o Positive i P Intake Manifoid i Battery Yellow White Kill Negative 23 4 i RH 548 28 Hp J i d e s m E EE a m y ie a Relay Cranking Relay Stud LU3H A LL Yellow Accessory Terminal 4 mA sl Solenoid oe Tang i ES Alternate Ignition OU Pressure Swite Oil Sentry Kill Green Solenold Shift tarter Assembly Violet B 15 EE A EE V Violet B 25 Amp Figure 8 14 Wiring Diagram 15 20 25 amp Regulated Battery Charging System Figure 8 15 15 amp Stator and Rectifier Regulator Figure 8 16 20 amp Stator and Rectifier Regulator 8 14 Section 8 Electrical System and Components 1st Style 25 Amp Stator 2nd Style Figure 8 17 25 amp Stator and Rectifier Regulators 3 amp Unregulated Charging System Ground To Kill Lead White Ignition Modules 7 NS LA Spark Plug Spark L Plug Y Lh wen mn mme wn mm Key fm mm mm mm mm mm mm mm X Sw
100. ake manifold not fully opening to WOT stop if so equipped SO OU E DOO exo o qoc Section 5B EFI Fuel System Electrical System The EFI system is a 12 VDC negative ground system If a fault code indicates a problem with an electrical designed to operate down to a minimum of 7 0 volts If component disconnect the ECU connector and test system voltage drops below this level the operation of Tor continuity between the component connector voltage sensitive components such as the ECU fuel terminals and the corresponding terminals in the ECU pump and injectors will be intermittent or disrupted connector using an ohmmeter Little or no resistance causing erratic operation or hard starting A fully should be measured indicating that the wiring of that charged 12 volt battery with a minimum of 350 cold particular circuit is OK An illustrated listing of cranking amps is important in maintaining steady and numerical terminal locations for each style of ECU reliable system operation Battery condition and state of connector is provided on pages 5B 28 5B 31 or charge should always be checked first when 5B 32 troubleshooting an operational problem 5B 28 for 35 Pin MA 1 7 Metal Cased ECU Keep in mind that EFl related problems are more often 5B 31 for 24 Pin MSE 1 0 Plastic Cased ECU caused by the wiring harness or connections than by 0B 32 for 32 Pin MSE 1 1 Plastic Cased ECU the EFI components Even small amounts o
101. alls at idle speed de 2 Go O O mo L PG fuel tank low Vacuum line between carburetor and regulator pinched cracked or leaking Carburetor idle speed set too low should be at least 1200 RPM Carburetor idle circuit restricted Dirty restricted air cleaner Dirty restricted lock off filter Frozen malfunctioning regulator Check adjust primary pressure Excessive external load on engine Excessive internal wear Loose leaking fuel enrichment hose Impco carburetor system Irregular or inconsistent idle 1 Improper operation adjustment of regulator idle adjustment screw throttle opening and or engine governor Secondary valve in regulator not closing Readjust idle screw couterclockwise so valve can close fully against seat Loose leaking vacuum line Loose carburetor mounting and or line connections Damaged diaphragm s within regulator Debris in regulator Flush debris from drain plug or remove regulator from system disassemble body and remove debris Dirt or debris in carburetor Remove carburetor disassemble and clean service as required If venturi Impco carburetor removal is performed mark its orientation to the carburetor body for proper reinstallation Loose leaking fuel enrichment hose Impco carburetor system Engine stalls during operation SC oS E T No fuel Faulty lock off or blocked filter Improper governor setting Damaged diaphragms within regulator Vacuum l
102. alue If 8 mm straight shank type bolts are used torque in increments to 22 7 N m 200 in Ib If 8 mm step down bolts are used torque in increments to 14 7 N m 130 in Ib If 6 mm straight shank bolts are used torque in increments to 11 3 N m 100 in Ib Illustrated instructions are provided in the service rod package See Figures 11 10 and 11 11 NOTE Align the chamfer of the connecting rod with the chamfer of its mating end cap When installed the flat faces of the connecting rods should face each other The faces with the raised rib should be toward the outside 11 3 Section 11 Reassembly Torque these to 22 7 N m 200 in Ib 8 mm Straight Shank Torque these to 14 7 N m 130 in Ib 8 mm Step Down Torque these to 11 3 N m 100 in Ib Figure 11 12 Apply Camshaft Lubricant to Cam 6 mm Straight Shank Lobes 2 Position the timing mark of the crankshaft gear at the 12 o clock position 3 Turn the governor cross shaft clockwise until the lower end of the shaft contacts the cylinder Make sure the cross shaft remains in this position while installing the camshaft See Figure 11 13 Figure 11 10 Connecting Rod Bolts 4 Slide the camshaft into the bearing surface of the crankcase positioning the timing mark of the camshaft gear at the 6 o clock position Make sure that the camshaft gear and crankshaft gear mesh with both timing marks aligned See Figure 11 13 Figure 11 11 Torquing Conn
103. and Components Starter Disassembly 1 Disconnect the lead wire from the solenoid 2 Remove the hex nuts securing the solenoid and remove the solenoid from the starter assembly 3 Remove the two thru bolts 4 Remove the commutator end cap 5 Remove the insulator and the brush springs from the brush spring holder 6 Remove the armature from the frame 7 Remove the drive lever and the armature from the drive end cap NOTE When removing the lever and the armature be careful not to lose the thrust washer 8 The stop collar consists of two similar pieces held in place by being snapped over a retainer The retainer is held in place by a groove in the armature shaft To remove the stop collar the two pieces must be pried off the retainer 9 When the stop collars are removed the retainer can be removed from the armature shaft Do not reuse the retainer Brush Replacement The brushes in the starter are part of the starter frame Brush kit Kohler Part No 52 221 01 S contains four replacement brushes and springs If replacement is necessary all four brushes should be replaced 1 Remove the brushes from the brush holder and remove the brush holder from the frame 2 Cutthe brush lead wire at the edge of the post with a pair of nippers 3 File off any burrs on the post 4 The replacement brushes have a solid portion on them which should be crimped on the post 5 Solder the crimped portion to the post 6
104. and tighten securely or reinstall the main fuse Start the engine and allow it to run for several minutes The MIL should remain off if the problem was corrected and the fault codes should not reappear codes 31 32 33 and 34 may require 10 15 minutes of running to reappear The following chart lists the fault codes what they correspond to and what the visual indications will be Following the chart is a list of the individual codes with an explanation of what triggers them what symptoms might be expected and the probable causes Diagnostic Code Summary OBD2 P Code 35 Pin 24 Pin 32 Pin Applicable ID e E MA 1 7 MSE 1 0 MSE 1 1 ee i 1 SE Metal Cased Plastic Cased Plastic Cased ECU Syst ECU System ECU System ECU System S E a foes cont on next page 5B 35 Section 5B EFI Fuel System OBD2 P Code Applicable to 32 Pin Connection or Failure Description MSE 1 1 ECU Syst em Only P0132 O Sensor Circuit Shorted to Battery P0134 O Sensor Circuit No Activity Detected 2 35 Pin 24 Pin KSE MA 1 7 MSE 1 0 MSE 1 1 Metal Cased Plastic Cased Plastic Cased ECU System ECU System ECU System Blink Gne Note P0117 Temperature Sensor Circuit Shorted to Ground Temperature Sensor Circuit Open Circuit or i Short to Battery H Failure Completing Autolearn TPS Offset N A below minimum allowable limit Failure Completing Autolearn TPS offset N A S above maximu
105. ankpin Plug Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments Gasket surfaces must also be free of deep scratches or nicks Inspect the main bearing if so equipped for wear or damage refer to Section 1 Specifications Tolerances and Special Torque Values Replace the crankcase using a miniblock or short block as required Check the cylinder bore wall for scoring In severe cases unburned fuel can cause scuffing and scoring of the cylinder wall It washes the necessary lubricating oils off the piston and cylinder wall As raw fuel seeps down the cylinder wall the piston rings make metal to metal contact with the wall Scoring of the cylinder wall can also be caused by localized hot spots resulting from blocked cooling fins or from inadequate or contaminated lubrication If the cylinder bore is badly scored excessively worn tapered or out of round resizing is necessary Use an inside micrometer to determine the amount of wear refer to the Specifications Tolerances and Special Torque Values in Section 1 then select the nearest suitable oversize of either 0 25 mm 0 010 in or 0 50 mm 0 020 in Resizing to one of these oversizes will allow usage of the available oversize piston and ring assemblies Initially resize using a boring bar then use the following procedures for honing the cylinder NOTE Some CH25 26 engines feature POWER BORE cylinders a s
106. antities and store in clean approved containers A container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps eliminate spillage during refueling e Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting e Do not add oil to the gasoline e Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 or higher In countries using the Research fuel rating method it should be 90 octane minimum Unleaded gasoline is recommended as it leaves less combustion chamber deposits and reduces harmful exhaust emissions Leaded gasoline is not recommended and must not be used on EFI engines or on other models where exhaust emissions are regulated Gasoline Alcohol blends Gasohol up to 1096 ethyl alcohol 9096 unleaded gasoline by volume is approved as a fuel for Kohler engines Other gasoline alcohol blends are not approved 5 1 Section 5 Fuel System and Governor Gasoline Ether blends Fuel Filter Methyl Tertiary Butyl Ether MTBE and unleaded Most engines are equipped with an in line filter gasoline blends up to a maximum of 1596 MTBE by Visually inspect the filter periodically and replace when volume are approved as a fuel for Kohler engines dirty with a genuine Kohl
107. ap Some Models 2 Adjust the idle speed screw and high speed stop as necessary Make sure the maximum engine Connect Spark Plug Leads speed does not exceed 3750 RPM no load 1 Connect the leads to the spark plugs See Figure 11 98 EB Figure 11 98 Connect Spark Plug Leads 11 29 Section 11 Reassembly 11 30 CH18 745 Section 12 Clutch Clutch General Some engines are equipped with a wet disc type clutch See Figure 12 1 for exploded view of clutch Nameplate Shifting Lever Gasket Pin Oil Seal Ball Bearing Snap Ring Pressure Plate e eech See e Retaining Rings Pilot Bearin Release S Sleeve Assen pi Clutch Assembly Assembly Bearing Release Adjusting Assembly Lock Figure 12 1 Wet Type Clutch Exploded View 12 1 Section 12 Clutch Service 2 After adjustment is made engage clutch and On this type an oil splash type lubrication system is check to make sure rollers go over center to lock used The proper oil level must be maintained to the unit in engaged position and prevent releasing provide efficient lubrication The oil should be changed under load If trouble persists after readjustment after each 100 hours of operation When refilling use clutch reconditioning is indicated 0 47 L 1 pt of motor oil of proper viscosity See chart below Reconditioning Drain the oil remove the nameplate and use the SAE Viscosity fo
108. apacitor voltage the later the trigger pulse will occur retarding the timing accordingly Troubleshooting CD Ignition Systems The CD ignition systems are designed to be trouble free for the life of the engine Other than periodically checking replacing the spark plugs no maintenance or timing adjustments are necessary or possible Mechanical systems do occasionally fail or break down however so the following troubleshooting information is provided to help you get to the root of a reported problem A CAUTION High Energy Electric Spark The CD ignition systems produce a high energy electric spark but the spark must be discharged or damage to the system can result Do not crank or run an engine with a spark plug lead disconnected Always provide a path for the spark to discharge to ground Reported ignition problems are most often due to poor connections Before beginning the test procedure check all external wiring Be certain all ignition related wires are connected including the spark plug leads Be certain all terminal connections fit snugly Make sure the ignition switch is in the run position Section 8 Electrical System and Components NOTE The CD ignition systems are sensitive to excessive load on the kill lead If a customer complains of hard starting low power or misfire under load it may be due to excessive draw on the kill circuit Perform the appropriate test procedure Test Procedure for Standard Fixed Timin
109. ars dirty typically every other time the main element is replaced Clean the area around the base of the inner element before removing it so dirt does not get into the engine Section 4 Air Cleaner and Air Intake System Do not wash the paper element and inner element or use compressed air this will damage the elements Replace dirty bent or damaged elements with new genuine Kohler elements as required Handle the new elements carefully do not use if the sealing surfaces are bent or damaged Check all parts for wear cracks or damage Replace any damaged components Install the new inner element followed by the outer element Slide each fully into place in the air cleaner housing Reinstall the end cap so the dust ejector valve is down and secure with the two retaining clips See Figure 4 12 Removal 1 Remove the upper valve cover screws on each side securing the main bracket and loosen the hose clamp on the adapter inlet or remove the adapter mounting screws Lift the entire air cleaner assembly off the engine Disassemble or service as required Installation 1 Install the main mounting bracket with the center section up and the cutout around the carburetor aligning the mounting holes with the four upper valve cover holes Install and torque the four valve cover mounting screws to 7 9 N m 70 in Ib Reconnect the hose to the adapter and tighten the clamp or install a new adapter gasket if th
110. as any scratches nicks or burrs can result in leaks See Service Bulletin 252 for further information Refer to A Guide to Engine Rebuilding TP 2150 A for additional information Measurement Guide TP 2159 B and Engine Inspection Data Record TP 2435 are also available use these to record inspection results Automatic Compression Release ACR Some engines are equipped with the optional Automatic Compression Release ACR mechanism The ACH lowers compression at cranking speeds to make starting easier Operation The ACR mechanism consists of a flyweight spring and pivoting control pin assembly attached to the gear on the camshaft At cranking speeds 700 RPM or lower the control pin protrudes above the exhaust cam lobe This pushes the exhaust valve off its seat during the first part of the compression stroke The reduced compression results in an effective compression ratio of about 2 1 during cranking After starting engine speed increases to over 700 RPM and centrifugal force overcomes the force of the flyweight spring The flyweight moves outward pulling the arm of the control pin so it pivots into the run position The control pin no longer has any effect on the exhaust valve and the engine operates at full power When the engine is stopped the spring returns the flyweight lever and control pin assembly to the compression release position ready for the next start Camshaft Inspection and Service Check the
111. assembly The full range of throttle plate movement will voltage from a customer supplied potentiometer or a not be achieved if the DLA is partially extended when single pole single throw SPST switch assembled Loosen the two DLA mounting plate screws located on the top of the actuator plate With Potentiometer Specifications the throttle linkage centered in the U Clip at the end of Wiper Voltage Engine Speed RPM the DLA shaft slide the DLA bracket assembly back 0 1 1860 low speed endpoint until the throttle plate is fully open Torque the i 2 5 N m 22 in Ib 1 9 variable speed endpoint mounting plate screws to 2 5 N m 22 in Ib 9 16 3600 high speed endpoint Troubleshooting Procedure Kee Engine starts but will not continue to run SPST Switch Specifications Bee ur 1 Checkthe linkage connection between the DLA Switch Position Engine Speed RPM and throttle plate Open 1860 low speed endpoint Closed 3600 high speed endpoint 2 Verify the DLA initializes when power is supplied D key switch in the start or run position GCU Safety Features In the event of an engine overspeed condition the 3 Test the potentiometer wiper output voltage if GCU will shut down the engine by grounding the equipped ignition modules 4 Testthe SPST switch if equipped The GCU will shut down the engine by grounding the ignition when power to the GCU is lost 5 Check the wire harness and connections Linkage E Engine d
112. ations touch the probe to the laminations inside the screw hole as some laminations have a rust preventative coating on the surface which could alter the resistance reading a If all of the resistance values are within the ranges specified in the table go to step 5 b If any of the resistance values are not within the ranges specified in the table that module is faulty and must be replaced NOTE The resistance values apply only to modules that have been on a running engine New service modules may have higher resistance until they have been run 8 9 Section 8 Electrical System and Components Ignition Module Resistance Table 24 584 03 or 24 584 11 1 11 16 in H 24 584 15 S or 24 584 36 S 2 1 16 in H Test 24 58403 5 584 15 S 24 584 36 S Ohmmeter 1 11 16 in H From No 945 to 890 to 590 to 1 to 4 1175 ohms 1175 ohms 616 ohms From No 149 to 119 to 183 to 2 to 4 166 ohms 136 ohms 208 ohms From No 3 50 to 5600 to 8000 to 3 to 4 7000 ohms 9000 ohms 40 000 ohms 5 Check and or adjust the ignition module air gap s An air gap of 0 28 0 33 mm 0 011 0 013 in must be maintained under all three legs of the ignition module s Checking adjusting should be performed with the parts at room temperature a If the module was not loosened or replaced check that the specified air gap is present under all three legs If the gap is correct reinstall the second mounting screw removed earl
113. aulty spark plugs Old stale fuel Incorrect fuel pressure Speed sensor loose or faulty TPS offset incorrect initialization TPS faulty Engine temperature sensor faulty Faulty coils Low system voltage Faulty injectors p d 9 DU c Orco qt 5B 26 Engine starts hard or fails to start when hot Faulty spark plugs Fuel pump not running Fuel pressure low Insufficient fuel delivery TPS offset incorrect Initialization Speed sensor loose or faulty TPS faulty Engine temperature sensor faulty Faulty injectors SO OU ENDO T xoc rc Engine stalls or idles roughly cold or warm Faulty spark plugs Insufficient fuel delivery TPS offset incorrect TPS faulty Faulty engine temperature sensor Faulty injectors QUI un es Engine misses hesitates or stalls under load 1 Fuel injector s fuel filter fuel line or fuel pick up dirty restricted Dirty air cleaner Insufficient fuel pressure or fuel delivery Vacuum intake air leak Improper governor setting adjustment or operation Speed sensor malfunction 7 TPS faulty mounting problem or TPS Initialization Procedure incorrect 8 Bad coil s spark plug s or wires Ol oo T9 9o Low Power Faulty malfunctioning ignition system Dirty air filter Insufficient fuel delivery Improper governor adjustment Plugged restricted exhaust One injector not working Basic engine problem exists TPS faulty or mounting exists Throttle plates in throttle body int
114. be effective the oil cooler must be kept free of debris To service the crankcase mounted oil cooler clean off the outside fins with a brush or with compressed air To service the blower housing mounted oil cooler clean the outside of fins with a brush Remove the two screws holding the cooler unit to the blower housing Tilt the cooler downward Clean the inside of the cooler with a brush or with compressed air After cleaning reinstall the oil cooler to the blower housing with the two mounting screws 6 4 Oil Sentry General Some engines are equipped with an optional Oil Sentry oil pressure monitor switch See Figure 6 8 If the pressure drops below an acceptable level the Oil Sentry will either shut off the engine or activate a warning signal depending on the application The pressure switch is designed to break contact as the oil pressure increases above 3 5 psi and make contact as the oil pressure decreases below 3 5 psi On stationary or unattended applications pumps generators etc the pressure switch can be used to ground the ignition module to stop the engine On vehicular applications lawn tractors mowers etc the pressure switch can only be used to activate a low oil warning light or signal NOTE Make sure the oil level is checked before each use and is maintained up to the F mark on the dipstick This includes engines equipped with Oil Sentry Installation The Oil Sentry pressure switc
115. before attempting to restart the engine If the starter is engaged while the flywheel is rotating the starter pinion and flywheel ring gear may clash resulting in damage to the starter Troubleshooting Guide Starting Difficulties Problem Possible Fault NOTE If the starter does not crank the engine shut off the starter immediately Do not make further attempts to start the engine until the condition is corrected NOTE Do not drop the starter or strike the starter frame Doing so can damage the starter Starter Removal and Installation Refer to the Disassembly and Reassembly Sections for starter removal and installation procedures Inertia Drive Electric Starters This subsection covers the operation troubleshooting and repair of the inertia drive permanent magnet electric starters Correction Battery 1 Check the specific gravity of battery If low recharge or replace battery as necessary Starter Does Not Energize Starter Switch or Solenoid 1 Clean corroded connections and tighten loose connections Wiring 2 Replace wires in poor condition and with frayed or broken insulation 1 By pass the switch or solenoid with a jumper wire If starter cranks normally replace the faulty components Batter 1 Check the specific gravity of battery If low recharge or replace x battery as necessary NE i Transmission or drive The transmission must be exactly in neutral to prevent Starter E
116. binding occurs loosen the screws reposition the pump retorque the hex flange screws and recheck the movement Governor Cross Shaft Oil Seal If the governor cross shaft seal is damaged and or leaks replace it using the following procedure Remove the oil seal from the crankcase and replace it with a new one Install the new seal to the depth shown in Figure 10 18 using a seal installer Governor Cross Shaft Seal 10 13 Section 10 Inspection and Reconditioning 10 14 CH18 745 Section 11 Reassembly General NOTE Make sure the engine is assembled using all specified torque values tightening sequences and clearances Failure to observe specifications could cause severe engine wear or damage Always use new gaskets Make sure all traces of any cleaner are removed before the engine is assembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Check the closure plate crankcase cylinder heads and valve covers to be certain that all of the old RTV has been removed Use gasket remover lacquer thinner or paint remover to remove any remaining traces Clean the surfaces with isopropyl alcohol acetone lacquer thinner or electrical contact cleaner Typical Reassembly Sequence The following sequence is suggested for complete engine reassembly This procedure assumes that all components are new or have been reconditioned and all com
117. ble as Kohler Part No X 75 23 S 5A 12 Regulator Service Every 1500 hours it is recommended that disassembly cleaning and resetting of the regulator be performed using the regulator rebuilding kit available Specific instructions are included in the rebuilding kit Perform the regulator service following the instructions provided As all adjustments and settings must be reset using specific test equipment this must be performed by qualified LP personnel only Impco Beam Regulator Service Kohler repair kit 24 757 40 S should be used to service the regulator every 1500 hours or whenever cleaning and servicing is required Nikki Regulator Service Kohler repair kit 24 757 39 S should be used every 1500 hours CH26 CH745 Section 5B Electronic Fuel Injection EFI Fuel System Contents Page s Description Initial Stating Priming PFOGeGUEe E 5B 2 disais gere EU a ees 5B 2 EFI Fuel System Components EE 5B 3 ee E 5B 3 Itiportant Serviee NOIBS E 5B 4 Electrical Components Electronic Control nib E Ll EEN 5B 4 5B 5 EIERE EE TETTE m ee 5B 5 5B 6 Throttle Position Sensor TPS and Initialization Procedure cccceecseeeeeeeeeeeeeeceeeeeeeeeeaeeeeees 5B 7 5B 10 Engine Oil Temperature Sensor 66 ccccecccsecceeesccseeceecceeeeesecsceseeteccsedseseceaceseseesncosaterestasterds 5B 10 5B 11 e EE RECEN E C Om 5B 11 5B 13 zen 5B 13 5B 14 uM ec vc Uc PI 5B 14 5B 17 Velo eel SIC MEL m E 5B 17 5B 18 S
118. bled Fuel Recommendations General Recommendations Purchase gasoline in small quantities and store in clean approved containers An approved container with a capacity of 2 gallons or less with a pouring spout is recommended Such a container is easier to handle and helps prevent spillage during refueling Donotuse gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting e Do not add oil to the gasoline e Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type Do not use leaded gasoline as component damage will result Any costs damages incurred as a result of using leaded fuel will not be warranted Use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 or higher In countries using the Research method it should be 90 octane minimum Gasoline Alcohol blends Gasohol up to 1096 ethyl alcohol 9096 unleaded gasoline by volume is approved as a fuel for Kohler EFI engines Other gasoline alcohol blends are not approved Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blends up to a maximum of 1596 MTBE by volume are approved as a fuel for Kohler EFI engines Other gasoline ether blends are not approved EFI Fuel System Components General The Electronic Fuel Injection EFI system is a complete engine fuel and ignition management design The system includes the following prin
119. bration indicating that they are spray pattern opening and closing 2 When temperatures prohibit touching listen for a buzzing or clicking sound with a screwdriver or mechanic s stethoscope see Figure 5B 19 m Listen Here Prete r it RECH LI e R ama sos H KZ 3 Multi Orifice Director Plate with Calibrated Opening Figure 5B 19 Checking Injectors 3 Disconnect the electrical connector from an injector and listen for a change in idle performance only running on one cylinder or a change in injector noise or vibration 1 Filter strainer in fuel supply 5 Armature 2 Electrical connection 6 Valve body 3 Solenoid winding 7 Valve needle 4 Valve housing Figure 5B 18 Fuel Injector Details If an injector is not operating it can indicate either a bad injector or a wiring electrical connection problem Check as follows The injector is opened and closed once for each crankshaft revolution however only one half the total NOTE Do not apply voltage to the fuel injector s amount of fuel needed for one firing is injected during Excessive voltage will burn out the injector s each opening The amount of fuel injected is controlled Do not ground the injector s with the ignition by the ECU and determined by the length of time the on Injector s will open turn on if relay is valve needle is held open also referred to as the energized injection duration or pulse width It may vary in l
120. can function normally When the engine is stopped manifold vacuum is terminated and the diaphragm relaxes and pushes down on the secondary valve lever preventing any fuel flow or leakage through the regulator From Primary Chamber 4 To Intake Manifold 11 Secondary Valve 12 Secondary Valve Seat 13 Secondary Chamber 14 Secondary Diaphragm 15 Secondary Diaphragm Spring Figure 5A 22 Secondary Chamber 16 Secondary Valve Lever 17 Vacuum Lock Off Diaphragm 18 Idle Adjust Screw 19 Balance Spring 5A 11 Section 5A LPG Fuel Systems Preventative Maintenance The regulator is preset at the factory and generally requires no further adjustment No periodic service is required Over time depending on fuel quality operating environment and system performance fuel deposits can accumulate inside the regulator Those regulators containing a drain plug Nikki should be drained every 500 hours to remove any accumulated deposits See Figure 5A 23 Regulator Drain Plug Figure 5A 23 Regulator Drain Plug some models 1 Turn supply valve off run engine out of fuel and turn off ignition switch 2 Disconnect and ground the spark plug leads 3 Remove the 1 8 pipe plug from bottom of regulator and drain any accumulated deposits See Figure 5A 23 4 Reinstall plug using pipe sealant with Teflon Loctite 592 or equivalent on threads and tighten securely If required a replacement plug is availa
121. chart on pages 5B 28 5B 31 or 5B 32 35 Pin MA 1 7 Metal Cased ECU Pin Circuits 12 and 27 24 Pin MSE 1 0 Plastic Cased ECU Pin Circuits 8 and 4 32 Pin MSE 1 1 Plastic Cased ECU Pin Circuits 8 and 4 a Repair or replace as required b Turn the idle speed screw back in to its original setting c Reconnect connector plugs start engine and retest system operation 5B 8 7 Remove the two mounting screws from the TPS Save the screws for reuse Remove and discard the faulty TPS Install the replacement TPS and secure with the original mounting screws a Reconnect both connector plugs b Perform the appropriate TPS Initialization Procedure integrating the new sensor to the ECU TPS Initialization Procedure For 35 Pin MA 1 7 Metal Cased ECU and 24 Pin MSE 1 0 Plastic Cased ECU only 1 Check that the basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 Remove disconnect ALL external loads from engine belts pumps electric PTO clutch alternator rectifier regulator etc 3 Start the engine and allow it to warm up for 5 10 minutes so oil temperature is above 55 C 130 F 4 Move the throttle control to the idle position and allow engine to stabilize for a minimum of one minute 5 Install a heavy rubber band around the throttle lever and the manifold boss to firmly hold the thro
122. chnician can access the fault code s to help determine what portion of the system is malfunctioning The 2 digit blink codes available based upon the style of ECU are listed on pages 5B 35 5B 36 The codes are accessed through the key switch and displayed as blinks or flashes of the MIL Access the codes as follows 1 Start with the key switch off 2 Turn the key switch on off on off on leaving it on in the third sequence The time between sequences must be less than 2 5 seconds 3 Any stored fault codes will then be displayed as a series of MIL blinks from 2 to 6 representing the first digit followed by a pause and another series of blinks from 1 to 6 for the second digit see Figure 5B 43 a Its a good idea to write down the codes as they appear as they may not be in numerical sequence b Code 61 will always be the last code displayed indicating the end of code transmission If code 61 appears immediately no other fault codes are present Section 5B EFI Fuel System Example of Diagnostic Display 1 per display initiated through ignition key sequencing NP Short Pauses Pauses spe E EE E AE Mw n H p Light remains on at end of transmission Figure 5B 43 After the problem has been corrected the fault codes may be cleared as follows 1 Disconnect the negative battery cable from battery terminal or remove the main fuse for the ECU for approximately 1 minute 2 Reconnect the cable
123. cipal components Fuel Pump FuelFilter e Fuel Rail Fuel Line s Fuel Pressure Regulator Fuel Injectors Throttle Body Intake Manifold e Engine Control Unit ECU e Ignition Coils Engine Oil Temperature Sensor e Throttle Position Sensor TPS e Speed Sensor Oxygen Sensor e Wire Harness Assembly amp Affiliated Wiring e Malfunction Indicator Light MIL Operation The EFI system is designed to provide peak engine performance with optimum fuel efficiency and lowest possible emissions The ignition and injection functions are electronically controlled monitored and continually corrected during operation to maintain the theoretical ideal or stoichiometric air fuel ratio of 14 7 1 The central component of the system is the Motronic Engine Control Unit ECU which manages system operation determining the best combination of fuel mixture and ignition timing for the current operating conditions An electric fuel pump is used to move fuel from the tank through the fuel line and in line fuel filter A fuel pressure regulator maintains a system operating pressure of 39 psi and returns any excess fuel to the tank At the engine fuel is fed through the fuel rail and into the injectors which inject it into the intake ports The ECU controls the amount of fuel by varying the length of time that the injectors are on This can range from 1 5 8 0 milliseconds depending on fuel requirements The cont
124. connecting the negative ground cable make sure all switches are OFF If ON a spark Will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present k Electrical Shock can cause injury Do not touch wires while engine is running Electrical Shock Never touch electrical wires or components while the engine is running They can be sources of electrical shock Section 1 Safety and General Information Engine Identification Numbers When ordering parts or in any communication involving an engine always give the Model Specification and Serial Numbers including letter suffixes if there are any The engine identification numbers appear on a decal or decals affixed to the engine shrouding See Figure 1 1 An explanation of these numbers is shown in Figure 1 2 Identification Decal Figure 1 1 Engine Identification Decal Location A Model No CH18S Command Engine 4 To Version Code ft Horizontal Cranksha S Electric Start Numerical Designation or Horsepower 730 17 17HP 740 18 18 HP 145 20 20 HP 22 22 HP 23 23 HP 25 25 HP 26 26 HP B Spec No CH730 0001 Variation of CH740 0001 Engine Model Code Basic Engine CH745 0001 Model Complete Spec Number CH18 Incorporating Model CH20 No with Variation No of CH22 624 cc Basic Spec CH25 CH22 23 674 cc CH26 C Serial No 3305810334 Year Manufactured Code JL Factory Code
125. crew to 9 9 N m 88 in Ib See Figure 5B 42 Make sure that the governor arm has not twisted up or down after the nut has been tightened An P 5B 25 Section 5B EFI Fuel System 4 Verify that the governor has been set correctly With the linkage still retained in the Full Throttle position Step 2 unsnap the bushing clip separate the linkage from the bushing and remove the bushing from the lever Follow Steps 3 and 4 in Checking the Initial Adjustment 5 Reconnect the dampening spring into its governor lever hole from the bottom Reinstall the bushing and reattach the throttle linkage See Figure 5B 37 Reattach the governor spring in the marked hole 6 Start the engine and allow it to fully warm up and establish closed loop operation approximately 5 10 min Check the speed settings and adjust as necessary first the low idle speed and then the high speed setting Troubleshooting General When troubleshooting a problem on an engine with EFI basic engine operating problems must be eliminated first before faulting the EFI system components What appears to be an EFI problem could be something as simple as a fuel tank with debris in the bottom or a plugged vent Be sure the engine is in good mechanical operating condition and all other systems are functional before attempting to troubleshoot the EFI system Troubleshooting Guide Engine starts hard or fails to start when cold Fuel pump not running F
126. d Special Tests and follow the prompts to stay off indicating the initialization procedure complete has been successful 4 Start the engine and immediately observe the Malfunction Indicator Light MIL The light should start blinking 4 consecutive times every 2 seconds 5B 9 Section 5B EFI Fuel System D Remove the jumper wire or plug from the service connector plug in wiring harness Run the engine at full throttle above 3000 RPM to warm up the engine and initiate O sensor function in closed loop operation Watch the MIL When the light starts blinking rapidly 5 blinks per second move the throttle lever to the low idle speed position Check and adjust the idle speed to 1500 RPM using a tachometer The lamp should continue to blink rapidly for another 30 seconds before switching to a slow blink When the MIL blinks slowly do not do anything but wait until the MIL shuts off This indicates that this procedure has been completed successfully Shut off the engine If the learn procedure was successfully completed the external loads removed disconnected in Step 2 may be reconnected If the procedure was unsuccessful see Steps a and b following a If during this procedure the MIL goes back into blinking 4 consecutive blinks every 2 seconds the engine and O sensor have cooled down and out of closed loop operation prohibiting the learning from occurring Repeat Steps 6
127. d Play Section 11 Reassembly 5 Reinstall the end play checking tool and recheck the end play Oil Pump Assembly The oil pump is mounted inside the closure plate If service was required and the oil pump was removed refer to the assembly procedures under Oil Pump Assembly in Section 10 Governor Gear Assembly The governor gear assembly is located inside the closure plate If service was required and the governor was removed refer to the assembly procedures under Governor Gear Assembly in Section 10 Thrust Bearing Washer and Shim Some specifications use a needle type thrust bearing thrust washer and shim spacer to control the end play of the crankshaft See Figure 11 16 If these items are noted during disassembly make sure they are reinstalled in the sequence shown in Figure 11 17 A different procedure will have to be followed to check and adjust crankshaft end play on these models Figure 11 16 Thrust B Used on Some Models Section 11 Reassembly Thrust Shim Needle Thrust Bearing my O Bearing Race Figure 11 17 Correct Sequence of Thrust Bearing Washer and Shim in Closure Plate The race for the thrust bearing presses loosely into the closure plate If it is not already installed push it into the crankshaft bore inside the closure plate Pack the thrust bearing with heavy grease and stick the bearing into the race Wipe some grease on the face of the thrust washer and stick it
128. d air if the system is open Cover any parts removed and wrap any open joints with plastic if they will remain open for any length of time New parts should be removed from their protective packaging just prior to installation Avoid direct water or spray contact with system components e Do not disconnect or reconnect the wiring harness connector to the control unit or any individual components with the ignition on This can send a damaging voltage spike through the ECU e Do not allow the battery cables to touch opposing terminals When connecting battery cables attach the positive cable to positive battery terminal first followed by negative cable to negative battery terminal Never start the engine when the cables are loose or poorly connected to the battery terminals Never disconnect battery while engine is running e Never use a quick battery charger to start the engine e Do not charge battery with key switch on Always disconnect negative battery cable lead before charging battery and also unplug harness from ECU before performing any welding on equipment 5B 4 Electrical Components Electronic Control Unit ECU FERE FE Fg ley Figure 5B 1 35 Pin MA 1 7 Metal Cased ECU Figure 5B 2 24 Pin MSE 1 0 Plastic Cased ECU Figure 5B 3 32 Pin MSE 1 1 Plastic Cased ECU Three different styles of ECU s have been utilized in EFI production
129. dle is forced Now turn the adjusting needle out counterclockwise 1 1 2 turns Start the engine and run at half throttle for 5 to 10 minutes to warm up The engine must be warm before making final settings Check that the throttle and choke plates can fully open NOTE The carburetor has a self relieving choke Choke plate and shaft assembly is spring loaded Check to make sure plate moves freely and is not binding and affecting idle fuel delivery Place the throttle control into the idle or slow position Turn the low idle speed adjusting screw in or out to obtain a low idle speed of 1200 RPM 75 RPM Check the speed using a tachometer NOTE The actual low idle speed depends on the application Refer to the equipment manufacturer s recommendations The low idle speed for basic engines is 1200 RPM To ensure best results when setting the low idle fuel needle the low idle speed should be 1200 RPM 75 RPM Turn the low idle fuel adjusting needle in slowly until engine speed decreases and then back out approximately 3 4 turn to obtain the best low speed performance Recheck the idle speed using a tachometer and readjust the speed as necessary Float It is not necessary to remove the carburetor from the engine to check and adjust the float Remove the air cleaner and breather hose Refer to Section 9 Disassembly 2 Disconnect the fuel line from the carburetor See Figure 5 6 3
130. e adapter was separated from the carburetor and torque the mounting fasteners to 7 3 N m 65 in Ib NOTE Adapter configurations may vary depending on engine and application involved Two adapters are shown in Figure 4 14 4 5 Section 4 Air Cleaner and Air Intake System Figure 4 14 Adapters for Heavy Duty Air Cleaners Figure 4 15 Cleanout Kit Installed on Blower Housing Air Intake Cooling System To ensure proper cooling make sure the grass screen cooling fan fins and external surfaces of the engine are kept clean at all times Every 100 hours of operation more often under extremely dusty or dirty conditions remove the blower housing and other cooling shrouds Clean the cooling fins and external surfaces as necessary Make sure the cooling shrouds are reinstalled Cleanout kits Kohler Part No 25 755 20 S black or 25 755 21 S gold are recommended to aid inspection and cleanout of the cooling fins See Figure 4 15 NOTE Operating the engine with a blocked grass screen dirty or plugged cooling fins and or cooling shrouds removed will cause engine damage due to overheating 4 6 CH18 745 Section 5 Fuel System and Governor Description The Command horizontal twins use three different types of fuel systems carbureted electronic fuel injection EFI or gaseous Gaseous fuel systems can be either liquefied petroleum gas LPG or LP or natural gas NG Some dual fuel engines have a c
131. e or replace regulator as required Dirty air cleaner or precleaner Choke plate in carburetor not opening completely Section 5A LPG Fuel Systems LPG Carburetor Adjustments General The LPG carburetor and regulator are designed to deliver the correct fuel to air mixture to the engine under all operating conditions The high and low idle fuel mixture settings are preset at the factory and cannot be adjusted These engines are equipped with an Impco or Nikki carburetor See Figure 5A 2 and 5A 3 Although both carburetors function similarly each Is unique and should not be interchanged Load Block Assembly Idle Speed Adjusting Screw Rear Plug with Sealing Washer 4 Figure 5A 3 Nikki Carburetor Impco carburetors also incorporate the use of an external Load Block assembly which controls the final fuel flow to the carburetor for all throttle positions except idle See Figure 5A 2 Calibrated and flow matched to the carburetor it functions similarly to preset fuel mixture settings in other carburetors The load block assembly is not available separately nor is any internal servicing permitted or possible If a problem is encountered and determined to be caused by the load block the carburetor should be replaced 5A 3 Section 5A LPG Fuel Systems High Altitude Operation Impco Carburetor The standard carburetor calibrations will provide 1 Turn off fuel supply at tank proper operation up to altitudes
132. e Figure 11 61 Start a few of the screws to hold it in place Figure 11 58 Installing Screws Locations 3 and 4 7 Install the inner baffles using the two remaining hex flange screws see Figures 11 59 and 11 60 and finger tighten Do not torque the screws at this time they will be tightened after the blower housing and outer baffles are installed Figure 11 61 Installing Blower Housing 3 Position the outer baffles and loosely start the mounting screws The two M6 screws go into the back of the cylinders The short M5 screws go into the lower holes closest to the blower housing The short screw on the oil filter side is also used to mount the wire harness clip Be sure any wire harnesses or leads are routed out through the proper offsets or notches so they will not be pinched between the blower housing and baffles See Figure 11 62 Figure 11 60 Finger Tighten Two Remaining Cover Screws Figure 11 62 Routing Wiring Harness and Leads 11 17 Section 11 Reassembly 4 Ifthe rectifier regulator was not removed attach the ground wire or metal grounding bracket for the rectifier regulator using the silver colored screw and washer to the lower blower housing hole See Figure 11 63 Figure 11 65 Tighten Baffle Mounting Screws 6 The metal grass screen can now be attached to Figure 11 63 Ground Lead Details the supports 5 Tighten all of the shrouding fasteners Torque the blower h
133. e being replaced Do not intermix the components 1 Check to make sure there are no nicks or burrs on the sealing surfaces of the cylinder head or the crankcase 11 11 Section 11 Reassembly Heads secured with hex flange screws 2 Install a new cylinder head gasket with printing up Figure 11 42 Cylinder Head Fastener Torque Sequence h m T i Heads secured with mounting studs nuts and ch washers Figure 11 40 Always Use New Head Gaskets 2 If all of the studs were left intact go to Step 6 If NOTE Match the numbers embossed on the any studs were disturbed or removed install new cylinder heads and crankcase See studs as described in Step 3 Do not use reinstall Figure 11 36 any loosened or removed studs 3 Install the cylinder head and start the four new 3 Install new mounting stud s into the crankcase hex flange screws a Thread and lock two of the mounting nuts together on the smaller diameter threads NOTE When installing cylinder heads new hex flange screws should always be used b Thread the opposite end of the stud with the preapplied locking compound into the 4 Torque the hex flange screws in two stages first crankcase until the specified height from the to 22 6 N m 200 in Ib then finally to 41 8 N m crankcase surface is achieved See Figure 370 in Ib following the sequence in Figure 11 43 When threading in the studs use a 11 42 steady tightening motion without
134. e idle speed screw of some EFI engines to help stabilize no load operating speeds See Figure 5B 36 1 3 mm 0 039 0 117 in Exposed Length Off End Of Adjustment Screw Dampening Spring some models Figure 5B 36 Idle Speed Screw Details 5B 23 Section 5B EFI Fuel System The idle speed adjustment procedure remains the same for engines with or without a dampening spring Typically no periodic servicing is necessary in this area If however removal replacement of the dampening spring is required reinstall it as follows 1 Thread the spring onto the end of idle screw leaving 1 3 mm 0 039 0 117 in of the spring extending beyond the end of the idle speed screw 2 Secure spring onto the screw with a small amount of Permabond LM 737 or equivalent Loctite adhesive Do not get any adhesive on free coils of spring 3 Start the engine and recheck the idle speed settings after sufficient warm up Readjust as required Initial Governor Adjustment The initial governor adjustment is especially critical on EFI engines because of the accuracy and sensitivity of the electronic control system Incorrect adjustment can result in overspeed loss of power lack of response or inadequate load compensation If you encounter any of these symptoms and suspect them to be related to the governor setting the following should be used to check and or adjust the governor and throttle linkage If the governor throttle compo
135. e running at 3000 RPM measure 1 If voltage is more than 12 5 volts charging voltage across battery terminals using a DC system is OK voltmeter If voltage is 12 5 volts or less the stator or diode are probably faulty Test the stator and diode Tests 2 3 and 4 2 Disconnect the charging lead from battery 2 f voltage is 28 volts or more stator winding is OK With engine running at 3000 RPM measure voltage from charging lead to ground using a If voltage is less than 28 volts test stator using DC voltmeter an ohmmeter Tests 3 and 4 3 With charging lead disconnected from battery 3 If resistance is low in both directions the diode and engine stopped measure resistance from is shorted Replace the diode Battery charging lead to ground using an ohmmeter Note reading If resistance is high in both directions the diode or stator winding is open Use Test 4 Reverse the leads and measure resistance again In one direction the resistance should be infinity ohms open circuit With the leads reversed some resistance should be measured about midscale on Rx1 range 4 Cutthe sleeving on the charging lead to 4 f resistance is approximately 1 07 ohms expose the diode connections stator winding is OK Measure the resistance from the stator side of If resistance is 0 ohms stator winding is diode to ground using an ohmmeter shorted Replace stator If resistance is infinity ohms stator winding or lead is open
136. eading is below specification or if pressure is present check the following table for possible causes and remedies 3 3 Section 3 Troubleshooting No Crankcase Vacuum Pressure in Crankcase Possible Cause Been 1 Crankcase breather clogged or inoperative Seals and or gaskets leaking Loose or improperly torqued fasteners Piston blowby or leaky valves Confirm by inspecting components Hestricted exhaust Compression Test Some of these engines are equipped with an automatic compression release ACR mechanism Because of the ACR mechanism it is difficult to obtain an accurate compression reading As an alternative perform a cylinder leakdown test Cylinder Leakdown Test A cylinder leakdown test can be a valuable alternative to a compression test By pressurizing the combustion chamber from an external air source you can determine if the valves or rings are leaking and how badly SPX Part No KO3219 formerly Kohler Part No 25 761 05 S is a relatively simple inexpensive leakdown tester for small engines The tester includes a quick disconnect for attaching the adapter hose anda holding tool Leakdown Test Instructions 1 Run engine for 3 5 minutes to warm it up 2 Remove spark plug s and air filter from engine 3 Rotate the crankshaft until the piston of cylinder being tested is at top dead center of the compression stroke Hold the engine in this position while testing The holding tool su
137. eaner Standard Air Cleaner Service Check the air cleaner daily or before starting the engine Check for and correct any buildup of dirt and debris along with loose or damaged components NOTE Operating the engine with loose or damaged air cleaner components could allow unfiltered air into the engine causing premature wear and failure Figure 4 2 Removing Latch Style Cover Air Cleaner Element Figure 4 3 Removing Knob Style Cover Precleaner Service If so equipped wash and reoil the precleaner every 25 hours of operation more often under extremely dusty or dirty conditions To service the precleaner perform the following steps 1 Unhook the latches or loosen the retaining knob and remove the cover 2 Remove the foam precleaner from the paper air cleaner element 4 1 Section 4 Air Cleaner and Air Intake System 3 Wash the precleaner in warm water with detergent Rinse the precleaner thoroughly until all traces of detergent are eliminated Squeeze out excess water do not wring Allow the precleaner to air dry 4 Saturate the precleaner with new engine oil Squeeze out all excess oil 5 Reinstall the precleaner over the paper air cleaner element 6 Reinstall the air cleaner cover Secure the cover with the two latches or the retaining knob Element Cover Wing Nut Figure 4 5 Removing Element Cover Wing Nut 4 2 Figure 4 7 Removing Rubber Seal from Bracket
138. ear spilled fuel Never use gasoline as a cleaning agent Figure 9 14 Disconnecting Pulse Line from Valve Cover Early Models Pulse Style Pumps 1 Disconnect the fuel lines at the carburetor and at the in line fuel filter See Figure 9 12 2 Disconnect the pulse vacuum line from the crankcase or from the valve cover on earlier models See Figures 9 13 and 9 14 3 Remove the two hex flange screws securing the fuel pump to the bracket or to the blower housing See Figure 9 15 The fuel pump body may be metal or plastic Figure 9 12 Disconnecting Fuel Inlet Line at Carburetor 9 4 Section 9 Disassembly Pump me CA j Figure 9 15 Removing Screws Holding Fuel Pump Metal Bodied Pump Shown Figure 9 17 Mechanical Fue Remove Control Panel If So Equipped 4 Note or mark the orientation of the fuel pump 1 Disconnect the Oil Sentry Indicator Light wires then remove the fuel pump with lines attached as shown in Figure 9 16 2 Disconnect the choke control cable from the control bracket 3 Disconnect the throttle control cable or shaft 4 Remove the panel from the blower housing Remove Throttle amp Choke Controls 1 Remove the four hex flange screws securing the control bracket and rear air cleaner bracket some models to the cylinder heads See Figures 9 18 and 9 19 Mechanical Fuel Pump The mechanical style fuel pump is part of the valve cover assembly See Figure
139. eck timing on both cylinders the lines you made on the blower housing should be 90 apart If they re not go to Test 4 Test 4 Test the ignition modules and connections Remove the blower housing from the engine Inspect the wiring for any damage cuts bad crimps loose terminals or broken wires Disconnect the leads from the ignition module s and clean all of the terminals male and female with aerosol electrical contact cleaner to remove any old dielectric compound dark residue dirt or contamination Disconnect the spark plug leads from the spark plugs Hemove one of the mounting screws from each of the ignition modules If the mounting screws are black remove them both and discard Replace them with part number M 561025 S Look in the mounting hole with a flashlight and use a small round wire brush to remove any loose rust from the laminations inside the mounting hole Refer to the chart on page 8 10 to identify which ignition module s you have If they are the smaller style check the vendor part number on the face All modules with vendor part numbers MA 2 MA 2A or MA 2B Kohler Part No 24 584 03 should be replaced with 24 584 11 or 24 584 15 S For small modules with vendor numbers MA 2C or MA 2D Kohler Part No 24 584 11 or the larger style modules 24 584 15 S and 24 584 36 S use a digital ohmmeter to check the resistance values and compare them to the table following When testing resistance to the lamin
140. ecting Rod End Cap 6 Repeat the above procedure for the other connecting rod and piston assembly Install Camshaft 1 Liberally apply camshaft lubricant Kohler Part No 25 357 14 S to each of the cam lobes Lubricate the camshaft bearing surfaces of the crankcase and the camshaft with engine oil See Figure Figure 11 13 Aligning Crankshaft and Camshaft 11 12 Timing Marks Camshaft End Play Install the shim removed during disassembly onto the camshaft 2 Position the camshaft end play checking tool on the camshaft See Figure 11 14 ad F i H d Figure 11 14 Checking Camshaft End Play 3 Apply pressure on the camshaft end play checking tool pushing camshaft toward crankshaft Use a feeler gauge to measure the camshaft end play between the shim spacer and the checking tool Camshaft end play should be 0 076 0 127 mm 0 003 0 005 in 4 Ifthe camshaft end play is not within the specified range remove the checking tool and replace the shim as necessary Several color coded shims are available White 0 69215 0 73025 mm 0 02725 0 02875 in Blue 0 4295 0 78105 mm 0 02925 0 03075 in Red 0 79375 0 83185 mm 0 03125 0 03275 in Yellow 0 84455 0 88265 mm 0 03325 0 03475 in Green 0 89535 0 99345 mm 0 03525 0 03675 in Gray 0 94615 0 98425 mm 0 03725 0 03875 in Black 0 99695 1 03505 mm 0 03925 0 04075 in P a SCH i e m Figure 11 15 Change Shim to Obtain Correct En
141. ections are properly secured the fuses are good and a minimum of 7 0 volts is being supplied If during cranking voltage drops below 7 0 volts a reduction of fuel pressure may occur resulting in a lean starting condition If required testing of the fuel pump and relay may be conducted 5B 19 Section 5B EFI Fuel System 1 Connect the black hose of Kohler pressure tester SPX Part No KO3217 4 to the test valve in the fuel rail Route the clear hose into a portable gasoline container or the equipment fuel tank Turn on the key switch to activate the pump and check the system pressure on the gauge If system pressure of 39 psi 3 is observed the relay fuel pump and regulator are working properly Turn the key switch off and depress the valve button on the tester to relieve the system pressure a Ifthe pressure is too high and the regulator is outside the tank just down line from the pump check that the return line from the regulator to the tank is not kinked or blocked If the return line is good replace the regulator see Regulator Service on page 5B 21 b If the pressure is too low install in line T SPX Part No KO3217 8 between the pump and regulator and retest the pressure at that point If it is too low there also replace the fuel pump If the pump did not activate step 2 disconnect the plug from the fuel pump Connect a DC voltmeter across the terminals in the plug turn on the key switc
142. ee Valve eege DIM EE KO3217 8 Jumper Plug Blue for plastic cased ECU s ssssssssnnsssenreessrrrreerrnrresrrrreesrrrrren KO3217 9 Some of the specialty tools are shown and mentioned at various points in this manual A complete catalog of available tools may be ordered under Kohler Part No TP 2546 The tool price list is available under Kohler Part No TP 2547 2 1 Section 2 Special Tools Figure 2 1 Tool Catalog and Price List Special Tools You Can Make Flywheel Holding Tool Flywheel removal and reinstallation becomes a snap using a handy holding tool which can be made out of an old junk flywheel ring gear as shown in Figure 2 2 Using an abrasive cut off wheel cut out a six tooth segment of the ring gear as shown Grind off any burrs or sharp edges The segment can be used in place of a strap wrench Invert the segment and place it between the ignition bosses on the crankcase so that the tool teeth engage the flywheel ring gear teeth The bosses will lock the tool and flywheel in position for loosening tightening or removing with a puller Figure 2 2 Flywheel Holding Tool Rocker Arm Crankshaft Tool If you don t have a spanner wrench to lift the rocker arms or turn the crankshaft you can make a tool for doing this out of an old junk connecting rod 2 2 Find a used connecting rod from a 10 HP or larger engine Remove and discard the rod cap If it is a Posi Lock rod you will also need to remove the stud
143. el line connections to prevent tampering and safety hazards with the high fuel pressure The old clamp must be cut to open a connection so replacement is necessary each time Pliers SPX Part No KO3217 5 is used to crimp the replacement clamps A CAUTION Standard fuel line is not compatible and must not be used Use only Oetiker clamps Kohler Part No 24 237 05 S on fuel line connections Throttle Body Intake Manifold Assembly Li i SS om ke K te 5 BL ow Idle Speed I Adjusting Screw A l P wi s Throttle Body Intake Manifold a Figure 5B 35 Upper Intake Manifold General The EFI engines have no carburetor so the throttle function regulate incoming combustion airflow is incorporated in the intake manifold assembly The manifold consists of a one piece aluminum casting which also provides mounting for the fuel injectors throttle position sensor fuel rail air baffle idle speed screw and air cleaner assembly Service The throttle body intake manifold is serviced as an assembly with the throttle shaft throttle plates and idle speed adjusting screw installed The throttle shaft rotates on needle bearings non serviceable capped with rubber seals to prevent air leaks Idle Speed Adjustment RPM General The idle speed is the only adjustment that may be performed on the EFI system The standard idle speed setting for EFI engines is 1500 RPM but certain applications might require a dif
144. elated a Circuit providing voltage or ground to TPS damaged b TPS signal input circuit damaged 5 Oxygen Sensor Harness Related a Oxygen sensor bad b Wiring problem to oxygen sensor c Muffler leak causing O sensor to falsely indicate a lean condition d Bad ground between ECU and Engine Code 51 32 Pin MSE 1 1 Plastic Cased ECU only Source Injector 1 circuit open shorted to ground or shorted to battery Explanation Injector 1 is not functioning because the circuit is open shorted to ground or shorted to battery Expected Engine Respon Engine will run very poorly with only one cylinder functioning se Possible Causes 1 Injector Related a Injector coil shorted or opened 2 Engine Wiring Harness Related a b Broken or shorted wire in harness ECU pin 14 to injector pin 2 ECU pin 28 to fuel pump relay pin 86 Note after key off then key on code 56 would be set also Fuel pump relay pin 87 to injector pin 1 Open main fuse F1 3 Fuel Pump Relay Related a Bad fuel pump relay Primary side functional but pin 30 to pin 87 remains open Primary side pin 85 to pin 86 is either open or shorted during engine operation Note after key off then key on code 56 would be set also 4 ECU Related a Circuit controlling injector 1 damaged b Circuit controlling fuel pump relay damaged Code 52 32 Pin MSE 1 1 Plastic Cased ECU only Source Injector 2 circuit
145. embly Figure 9 55 Removing Plastic Type Grass Screen Figure 9 57 Removing Flywheel Fastener Using Strap Wrench 2 Remove the four hex flange screws and fan See Figure 9 56 2 Remove the hex flange screw and washer 3 Use a puller to remove the flywheel from the crankshaft See Figure 9 58 NOTE Always use a flywheel puller to remove the flywheel from the crankshaft Do not strike the crankshaft or flywheel as these parts could become cracked or damaged Striking the puller or crankshaft can cause the crank gear to move affecting the crankshaft end play Figure 9 56 Removing Fan Remove Flywheel 1 Use a flywheel strap wrench or holding tool see Section 2 to hold the flywheel and loosen the hex flange screw securing the flywheel to the crankshaft See Figure 9 57 NOTE Always use a flywheel strap wrench or holding tool to hold the flywheel when loosening or tightening the flywheel Y screw Do not use any type of bar or Figure 9 58 Removing Flywheel with a Puller wedge to hold the flywheel Use of such tools could cause the flywheel to become 4 Remove the woodruff key from the crankshaft cracked or damaged Remove Stator and Backing Plates 1 Remove the four hex flange screws securing the backing plates and stator wire bracket if equipped See Figure 9 59 Remove the backing plates and stator wire bracket 9 15 Section 9 Disassembly 2 Locate the three splitting tabs that are cast
146. emove the hex flange screws securing the bracket and base See Figures 4 9 and 4 10 Remove the bracket 3 Pinch the sealing collar on the breather hose and push it down through the hole in the air cleaner base Carefully feed the upper section of the breather tube down through the base See Figure 4 11 4 Remove the base and gasket 5 Reverse the procedure to reinstall new or serviced components Torque screws to 9 9 N m 88 in Ib Heavy Duty Air Cleaner General The heavy duty air cleaner consists of a cylindrical housing typically mounted to a bracket off the upper valve cover screws and connected with a formed rubber hose to an adapter on the carburetor or throttle body intake manifold EFI units The air cleaner housing contains a paper element and inner element designed for longer service intervals The system is CARB EPA certified and the components should not be altered or modified in any way Figure 4 12 Heavy Duty Air Cleaner To Service Every 250 hours of operation more often under extremely dusty or dirty conditions replace the paper element and check the inner element Follow these steps 1 Unhook the two retaining clips and remove the end cap from the air cleaner housing 2 Pull the air cleaner element out of the housing See Figure 4 13 Figure 4 13 Removing Elements 3 After the element is removed check the condition of the inner element It should be replaced whenever it appe
147. ength from 1 5 8 milliseconds depending on the speed 1 Disconnect the electrical connector from both and load requirements of the engine injectors Plug the 12 volt test light SPX Part No KO3217 6 in one connector 5B 15 Section 5B EFI Fuel System Check all electrical connections connectors and wiring harness leads if resistance is incorrect Injector leakage is very unlikely but in those rare instances it can be internal past the tip of the valve needle or external weeping around the injector body See Figure 5B 21 The loss of system pressure from the leakage can cause hot restart problems and longer cranking times To check for leakage it will be necessary to remove the blower housing which may involve removing the engine from the unit Figure 5B 20 Volt Test Light 2 Make sure all safety switch requirements are met Crank the engine and check for flashing of test light Repeat test at other connector a If flashing occurs use an ohmmeter Rx1 Check for leaks scale and check the resistance of each injector across the two terminals Proper resistance is 12 20 Q If injector resistance is correct check whether the connector and injector terminals are making a good connection If the resistance is not correct Figure 5B 21 Injector Inspection Points replace the injector following steps 1 8 and 13 16 below 1 Engine must be cool Depressurize fuel system through test valve in fuel rail b If no fla
148. enoid The pin should retract with the power on and return to its original position with the power off Test several times to verify operation 5 5 Section 5 Fuel System and Governor Carburetor Adjustments General In compliance with government emission standards the carburetor is calibrated to deliver the correct air to fuel mixture to the engine under all operating conditions The high speed mixture is preset and cannot be adjusted Pre compliance carburetors contain a low idle fuel adjusting needle on certified compliance carburetors both the low and high speed mixture circuits are pre established and cannot be adjusted The low idle speed RPM is the only adjustment available See Figures 5 4 and 5 5 Low Idle Speed Adjustment Low Idle Fuel Adjusting Needle Figure 5 4 Pre Compliance Carburetor with Low Idle Adjustment E Fuel Shut Off Solenoid Main Jet Location Figure 5 5 Certified Compliance Carburetor NOTE Carburetor adjustments should be made only after the engine has warmed up Adjusting Low Idle Speed and Fuel Some Models To adjust the carburetor idle speed see Figure 5 4 and follow these steps 5 6 With the engine stopped turn the low idle fuel adjusting needle in clockwise until it bottoms lightly NOTE The tip of the idle fuel adjusting needle is tapered to critical dimensions Damage to the needle and the seat in the carburetor body will result if the nee
149. entation of the new pump is consistent with the removed pump Internal damage may occur if installed incorrectly 2 Install the fuel pump using the two hex flange screws Torque the screws to 2 3 N m 20 in Ib Section 11 Reassembly Je Plastic Cased Pulse Fuel Pump Figure 11 74 Reinstalled Fuel Pump Install Carburetor Figure 11 76 Ground Lead on Carburetor Mounting Screw A WARNING Explosive Fuel Gasoline may be present in the carburetor and fuel 3 Torque the two carburetor mounting screws to system Gasoline is extremely flammable and its 6 2 7 3 N m 55 65 in Ib vapors can explode if ignited Keep sparks and other sources of ignition away from the engine Install External Governor Controls 1 Install the governor lever onto the governor cross 1 Install a new carburetor gasket Make sure all shaft See Figure 11 77 holes align and are open 2 Install the carburetor throttle linkage and governor lever as an assembly See Figure 11 75 If a plastic intake manifold is used and the carburetor is equipped with a fuel solenoid attach the ground lead to the carburetor mounting screw See Figure 11 76 i D e C Br e E L S ri a d a wl V i Figure 11 77 Install Governor Lever to Shaft 11 21 Section 11 Reassembly 2 Make sure the throttle linkage is connected to the governor lever and the throttle lever on the carburetor 3 Move the governor lever toward the carbu
150. er aace dita Gerne disse A 6 0 9 0 N m 53 79 in Ib Delco Hemy Staelens e E a 4 0 6 0 N m 35 53 in Ib Nut Positive Brush Lead Torque Nippondenso Starte EE 8 0 12 0 N m 71 106 in Ib Delco Remy Starner E 8 0 11 0 N m 71 97 in Ib Stator MOUMTING Screw erte UE 6 2 N m 55 in Ib Throttle Choke Controls Governor Control Lever Fastener TOrque cccccceeeeeseeeeeeeeeesaeeeeees 9 9 N m 88 in Ib Valve Cover Valve Cover Fastener Torque Gasket Style Cover 3 4 N m 30 in Ib Black O Ring Style Cover w Shoulder Gcrews nennen nennen nnns 5 6 N m 50 in Ib w Flange Screws and Spacers cccceeccceseeececeeeeeeteeseeeeeeeeeeees 9 9 N m 88 in Ib Brown O Ring Style Cover w Integral Metal Spacers 9 9 N m 88 in Ib Valves and Valve Lifters Hydraulic Valve Lifter to Crankcase Running Clearance 0 0241 0 0501 mm 0 0009 0 0020 in Intake Valve Stem to Valve Guide Running Clearance 0 038 0 076 mm 0 0015 0 0030 in Exhaust Valve Stem to Valve Guide Running Clearance 0 050 0 088 mm 0 0020 0 0035 in Intake Valve Guide I D Kl 7 038 7 058 mm 0 2771 0 2779 in Max Wear mn 7 1385 mm 0 2809 in 1 13 Section 1 Safety and General Information Valves and Valve Lifters cont Exhaust Valve Guide I D KI 7 038 7 058 mm 0 2771 0 2779 in HE GR er iai Eoo ett tiered sania N a nm 7 159 mm 0 2819 in
151. er filter Other gasoline ether blends are not approved Fuel System Tests When the engine starts hard or turns over but will not start it is possible that the problem is in the fuel system To find out if the fuel system is causing the problem perform the following tests Troubleshooting Fuel System Related Causes Checkthe following a Make sure the fuel tank contains clean fresh proper fuel Make sure the vent in fuel tank is open Make sure the fuel valve is open Make sure vacuum and fuel lines to fuel pump are secured and in good condition Check for fuel in the combustion chamber If there is fuel at the tip of the spark plug fuel is a Disconnect and ground spark plug leads reaching the combustion chamber b Close the choke on the carburetor c Crankthe engine several times If there is no fuel at the tip of the spark plug check d Remove the spark plug and check for fuel at for fuel flow from the fuel tank Test 3 the tip Check for fuel flow from the tank to the fuel pump If fuel does flow from the line check for faulty fuel a Remove the fuel line from the inlet fitting of pump Test 4 fuel pump b Hold the line below the bottom of the tank If fuel does not flow from the line check the fuel Open the shut off valve if so equipped and tank vent fuel pickup screen in line filter shut off observe flow valve and fuel line Correct any observed problem and reconnect the line Check the o
152. eration The ignition module for this system operates in the same fashion as the fixed timing module except the trigger circuit for the semiconductor L2 Figure 8 5 is replaced by the spark advance module Figure 8 7 8 6 The pulse generated by the input coil of the ignition module L1 Figure 8 5 is fed to the input of the conditioning circuit The conditioning circuit shapes this pulse putting it in a useable form for the additional circuits This pulse starts the charge pump which charges a capacitor in a linear fashion that can be directly related to the engine speed At the same time the pulse resets the delay circuit for length of the pulse width The comparator is off during this period and no output is generated As soon as the original pulse drops back to zero the capacitor in the delay circuit begins to charge When the charge on the delay capacitor exceeds the charge on the charge pump capacitor the comparator changes state activating the pulse generator This pulse turns ON the CD ignition module semiconductor Energy is then transferred to the secondary of the output transformer T1 Figure 8 5 The high voltage pulse generated here is delivered to the spark plug causing arcing of the spark gap and igniting the fuel air mixture in the combustion chamber As the trigger pulse is generated all associated circuits are reset their capacitors discharged The longer it takes the delay circuit to surpass the charge pump c
153. erval or wrong weight or type of oil was used to name a few NOTE Itis good practice to drain oil at a location away from the workbench Be sure to allow ample time for complete drainage Cleaning the Engine After inspecting the external condition of the engine clean the engine thoroughly before disassembling it Also clean individual components as the engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow the manufacturer s instructions and safety precautions carefully Make sure all traces of the cleaner are removed before the engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down the lubricating properties of engine oil Basic Engine Tests Crankcase Vacuum Test A partial vacuum should be present in the crankcase when the engine is operating at normal temperatures Pressure in the crankcase normally caused by a clogged or improperly assembled breather can cause oil to be forced out at oil seals gaskets or other available spots Crankcase vacuum is best measured with either a water manometer SPX Part No KO1048 formerly Kohler Part No 25 761 02 S or a vacuum gauge SPX Part No KO3223 formerly Kohler Part No 25 761 22 S Complete instructions are provided in the kits
154. ervicing Fuel Rail Fuel Rail e Locking Clip Fuel Injector Figure 5B 33 Manifold Assembly 5B 22 General The fuel rail is a formed tube assembly that feeds fuel to the top of the injectors The tops of the injectors fit into formed cups in the fuel rail When the rail is fastened to the manifold the injectors are locked into place A small retaining clip provides a secondary lock Incorporated into the fuel rail is a pressure relief test valve for testing operating pressure or relieving fuel system pressure for servicing The fuel supply line is attached to the barbed end of the fuel rail with an Oetiker hose clamp Service The fuel rail is mounted to the throttle body intake manifold It can be detached by removing the two mounting screws and the injector retaining clips Thoroughly clean the area around all joints prior to any disassembly No specific servicing is required unless operating conditions indicate that it needs internal cleaning or replacement Fuel Line Figure 5B 34 High Pressure Fuel Line General High pressure fuel line with an SAE R9 rating is required for safe and reliable operation due to the higher operating pressure of the EFI system If hose replacement is necessary order Fuel Line Service Kit Part No 24 353 42 S containing 5 ft of high pressure hose and 10 Oetiker clamps or use only the type specified Special Oetiker clamps Kohler Part No 24 237 05 S are used on all fu
155. es Below Serial No 2403500008 0 050 0 750 mm 0 0020 0 0295 in Crankshaft Bore In Crankcase wr o tee raaa 40 965 41 003 mm 1 6128 1 6143 in Max VV AP Hio ec 41 016 mm 1 6148 in Crankshaft to Sleeve Bearing Crankcase Running Clearance New 0 03 0 09 mm 0 0012 0 0035 in Crankshaft Bore In Closure Plate New eeeeeeeeeee 40 987 40 974 mm 1 6136 1 6131 in Crankshaft Bore In Closure Plate to Crankshaft Running Clearance NEW enne 0 039 0 074 mm 0 0015 0 0029 in Flywheel End Main Bearing Journal EE EE 40 913 40 935 mm 1 6107 1 6116 in OD Max Wear Eu 40 84 mm 1 608 in Max lape PD DD 0 022 mm 0 0009 in Max Out Ol FOUN 2 eei E eebe 0 025 mm 0 0010 in Closure Plate End Main Bearing Journal GRE CMM M KIA 40 913 40 935 mm 1 6107 1 6116 in OD Max Wear Limit idis esae eege 40 84 mm 1 608 in Max Ez lori DEEP EI MEER RE 0 022 mm 0 0009 in Max Out of Round ME 0 025 mm 0 0010 in Connecting Rod Journal GEpE E 35 955 35 973 mm 1 4156 1 4163 in SE RENE We at Eu 35 94 mm 1 415 in Max Tape ge eT HE 0 018 mm 0 0007 in Max e e Ee ui sooo eet acie ectetuer bte e noe ea 0 025 mm 0 0010 in Crankshaft T I R PTO End Crank Im Engine xoc ceci eoe noeh ee 0 279 mm 0 0110 in Entire Crank V BIoGKS iE rre ages eae Eo reed xe be OE genes 0 10 mm 0 0039 in Cylinder Bore Cylinder Bore I
156. ew diameter Section 1 The corresponding oversize Kohler replacement piston will then fit correctly 3 When the bore is within 0 064 mm 0 0025 in of the desired size remove the coarse stones and replace them with burnishing stones Continue with the burnishing stones until the bore is within 0 013 mm 0 0005 in of the desired size and then use finish stones 220 280 grit and polish the bore to its final size A crosshatch should be observed if honing is done correctly The crosshatch should intersect at approximately 23 33 off the horizontal Too flat an angle could cause the rings to skip and wear excessively and too steep an angle will result in high oil consumption See Figure 10 3 Figure 10 3 Cylinder Bore Crosshatch after 10 Honing 4 After resizing check the bore for roundness taper and size Use an inside micrometer telescoping gauge or bore gauge to take measurements The measurements should be taken at three locations in the cylinder at the top middle and bottom Two measurements should be taken perpendicular to each other at each of the three locations Clean Cylinder Bore After Honing Proper cleaning of the cylinder walls following boring and or honing is very critical to a successful overhaul Machining grit left in the cylinder bore can destroy an engine in less than one hour of operation after a rebuild 10 3 Section 10 Inspection and Reconditioning The final cleaning operati
157. ewind a spring that has come out of the keeper Order and install a new spring and keeper assembly 4 Cleanall old grease and dirt from the starter components Generously lubricate the spring and center shaft with any commercially available bearing grease ZA Reassembly 1 Make sure the spring is well lubricated with grease Place the spring and keeper assembly inside the pulley with spring towards pulley See Figure 7 7 2 Install the pulley assembly into the starter housing See Figure 7 8 Make sure the pulley is fully seated against the starter housing Do not wind the pulley and recoil spring at this time Housing Figure 7 8 Installing Pulley and Spring into Housing 3 Install the pawl springs and pawls into the starter pulley See Figure 7 9 Section 7 Retractable Starter 4 Place the brake washer in the recess in starter 7 Tension the spring and install the rope and handle pulley over the center shaft as instructed in steps 6 through 12 under Rope Replacement on page 7 2 5 Lubricate the brake spring sparingly with grease Place the spring on the plain washer Make sure 8 Install the starter to the engine blower housing as the threads in the center shaft remain clean dry instructed in To Install Starter on page 7 1 and free of grease and oil 6 Apply a small amount of Loctite No 271 to the threads of the center screw Install the center screw with the washer and retainer to the center
158. expander and then the rails Make sure the ends of expander are not overlapped 2 Middle Compression Ring Center Groove Install the center ring using a piston ring installation tool Make sure the identification mark is up or the dykem stripe if contained is to the left of the end gap 3 Top Compression Ring Top Groove Install the top ring using a piston ring expender Make sure the identification mark is up or the dykem stripe if contained to the left of the end gap Connecting Rods Offset stepped cap connecting rods are used in all these engines Inspection and Service Check the bearing area big end for excessive wear score marks running and side clearances refer to Section 1 Specifications Tolerances and Special Torque Values Replace the rod and cap if scored or excessively worn Section 10 Inspection and Reconditioning Service replacement connecting rods are available in STD crankpin size and 0 25 mm 0 010 in undersize The 0 25 mm 0 010 in undersized rod can be identified by the drilled hole located in the lower end of the rod shank Always refer to the appropriate parts information to ensure that correct replacements are used Hydraulic Lifters Inspection Check the base surface of the hydraulic lifters for wear or damage If the lifters need to be replaced apply a liberal coating of Kohler lubricant 25 357 14 S to the base of each new lifter before it is installed
159. f corrosion or oxidation on the terminals can interfere with the NOTE When performing voltage or continuity tests milliamp currents used in system operation Cleaning avoid putting excessive pressure on or the connectors and grounds will solve problems in against the connector pins Flat pin probes many cases In an emergency situation simply are recommended for testing to avoid disconnecting and reconnecting the connectors may spreading or bending the terminals clean up the contacts enough to restore operation at least temporarily 5B 27 Section 5B EFI Fuel System 95 Pin MA 1 7 Metal Cased ECU Systems Pinf Component Ignition Coil 1 Not used Engine Speed Sensor ECU Production Test Terminal Not Used Not Used Not Used TPS Initialization Terminal Engine Ground O Sensor Not Used Throttle Position Sensor Not Used Oil Temperature Sensor Not Used ECU Permanent Battery Voltage ECU Switched Battery Voltage Engine Ground Ignition Coil 2 Vehicle Ground Engine Speed Sensor Not Used Not Used Not Used Throttle Position Sensor Not Used Throttle Position Sensor Oil Temperature Sensor Power Relay Not Used Not Used Malfunction Indicator Light Not Used Vehicle Ground Not Used Fuel Injectors O OO Jo Om P ob 5B 28 Section 5B EFI Fuel System SHV B MO SAA 1 y pejj 2eds esJag o Sean B yunu Bujunp uojDuedo pyg Joy e
160. ferent setting Check the equipment manufacturer s recommendation For starting and warm up the ECU will adjust the fuel and ignition timing based upon ambient temperature engine temperature and loads present In cold conditions the idle speed will probably be higher than normal for a few moments Under other conditions the idle speed may actually start lower than normal but Section 5B EFI Fuel System gradually increase to the established setting as operation continues Do not attempt to circumvent this warm up period or readjust the idle speed during this time The engine must be completely warmed up for accurate idle speed adjustment Adjustment Procedure 1 Make sure there are no fault codes present in the ECU memory 2 Start the engine and allow it to fully warm up and establish closed looped operation approximately 5 10 min 3 Place the throttle control in the idle slow position and check the idle speed with a tachometer Turn the idle speed screw in or out as required to obtain 1500 RPM or the idle speed specified by the equipment manufacturer 4 Thelow idle speed adjustment can affect the high speed setting Move the throttle control to the full throttle position and check the high speed Adjust as necessary to 3750 RPM no load or the speed specified by the equipment manufacturer Idle Speed Screw Dampening Spring A small dampening spring Kohler Part No 24 089 42 S is attached to the end of th
161. fficient to turn over the engine recharge the battery Battery Maintenance Regular maintenance is necessary to prolong battery life A WARNING Explosive Gas Batteries produce explosive hydrogen gas while being charged To prevent a fire or explosion charge batteries only in well ventilated areas Keep sources of ignition away from the battery at all times Keep batteries out of the reach of children Remove all jewelry when servicing batteries Before disconnecting the negative ground cable make sure all switches are OFF If ON a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or gasoline vapors are present 1 Regularly check the level of electrolyte Add distilled water as necessary to maintain the recommended level NOTE Do not overfill the battery Poor performance or early failure due to loss of electrolyte will result Section 8 Electrical System and Components 2 Keep the cables terminals and external surfaces of the battery clean A build up of corrosive acid or grime on the external surfaces can cause the battery to self discharge Self discharge occurs rapidly when moisture is present 3 Wash the cables terminals and external surfaces with a mild baking soda and water solution Rinse thoroughly with clear water NOTE Do not allow the baking soda solution to enter the cells as this will destroy the electrolyte Battery Test To test the battery you w
162. for continuity from pin 19 of the ECU connector see page 5B 32 to the shell of the oxygen sensor and from pin 20 to the sensor terminal of the main harness Both tests should indicate continuity Section 5B EFI Fuel System a Ifthere is no continuity displayed in either of Electrical Relay the tests check the harness circuit for breaks or damage and the connections for poor contact moisture or corrosion If no continuity was found in the first test also check for a poor broken ground path back through the exhaust system engine and mounting sensor is grounded through its shell b If continuity is indicated go to step 6 6 With the key switch in the on run position using a high impedance voltmeter check the voltage from the wiring harness oxygen sensor connector to the engine ground location Look for a steady voltage from 350 550 mv 0 35 0 55 v Figure 5B 13 Electrical Relay a If voltage reading is not as specified move the General E3 black voltmeter lead to the negative post ofthe The electrical relay is used to supply power to the battery to be certain of a good ground If the injectors coils and fuel pump When the key switch is voltage is still not correct the ECU is probably turned on and all safety switch requirements met the bad relay provides 12 volts to the fuel pump circuit injectors and ignition coils The fuel pump circuit is b If voltage readings are correct clear the fault cont
163. g CD Ignition System Isolate and verify the trouble is within the engine ignition system 1 Locate the plug connectors where the wiring harnesses from the engine and equipment are joined Separate the connectors and remove the white kill lead from the engine connector Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground Try to start the engine to verify whether the reported problem is still present a Ifthe problem is gone the electrical system on the unit is suspect Check the key switch wires connections safety interlocks etc b If the problem persists the condition is associated with the ignition or electrical system of the engine Leave the kill lead isolated until all testing is completed NOTE If the engine starts or runs during any of the testing you may need to ground the kill lead to shut it down Because you have interrupted the kill circuit it may not stop using the switch 2 Test for spark on both cylinders with Kohler ignition tester SPX Part No KO1046 formerly Kohler Part No 24 455 02 S Disconnect one spark plug lead and connect it to the post terminal of the tester Connect the clip to a good ground not to the spark plug Crank the engine and observe the tester spark gap Repeat the procedure on the other cylinder Remember to reconnect the first spark plug lead a If one side is not firing check all wiring connections and terminati
164. g Coking is normal on intake valves and is not replaced Note the warped head margin damaged and harmful If the seat is good the valve could be reused too narrow These conditions could be attributed to after cleaning excessive hours or a combination of poor operating conditions 10 6 Excessive Combustion Temperatures The white deposits seen here indicate very high combustion temperatures usually due to a lean fuel mixture Section 10 Inspection and Reconditioning Stem Corrosion Moisture in fuel or from condensation are the most common causes of valve stem corrosion Condensation occurs from improper preservation during storage and when engine is repeatedly stopped before it has a chance to reach normal operating temperatures Replace corroded valves Gum Gum deposits usually result from using stale gasoline Gum is a prevalent cause of valve sticking The cure is to ream the valve guides and clean or replace the valves depending on their condition Overheating An exhaust valve subject to overheating will have a dark discoloration in the area above the valve guide Worn guides and faulty valve springs may cause this condition Also check for clogged air intake and blocked fins when this condition is noted 10 7 Section 10 Inspection and Reconditioning Valve Guides If a valve guide is worn beyond specifications it will not guide the valve in a straight line This may result in burnt valve faces or seat
165. ge in the sensor output signal Expected Engine Response Open loop operation only may cause a drop in system performance and fuel efficiency Possible Causes 1 Engine Wiring Harness Related a Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU 2 Oxygen Sensor Related a Sensor connector or wiring problem b Sensor contaminated or damaged c Sensor below the minimum operating temperature 375 C 709 F d Poor ground path from sensor to engine sensor grounds through shell see Oxygen Sensor section Code 33 Source Oxygen Sensor Fuel System Explanation System too rich Temporary fuel adaptation control is at the upper limit Expected Engine Response Erratic performance Will run rich smoke Possible Causes 1 Fuel Supply Related nothing lean only rich a Restricted return line causing excessive fuel pressure b Fuel inlet screen plugged in tank fuel pump only c Incorrect fuel pressure at fuel rail 2 Oxygen Sensor Related Sensor connector or wiring problem Sensor contaminated or damaged Exhaust leak Poor ground path Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU Papp Section 5B EFI Fuel Sy
166. ger Inner Half Around Spring Retainer 6 Hold the base of the tool with a 1 1 8 wrench and turn the center screw clockwise with a 1 2 or 13 mm wrench to draw the spring retainer up around the retaining ring Stop turning when resistance increases Disassemble and remove tool 7 Reinstall the dust cover Starter Disassembly 1 Remove the drive components following the instructions for servicing the drive Section 8 Electrical System and Components 2 Locate the small raised line on the edge of the drive end cap On starters with Style A commutator end caps it will be aligned with a premarked line on the starter frame The frame is not premarked on starters with Style B end caps Place a piece of masking tape on the frame and mark a line on the tape in line with the raised line on the end cap See Figure 8 37 Remove the thru bolts Hemove the commutator end cap with brushes and brush springs Style A Style B end caps remove as a separate piece with the brushes and carrier remaining in the frame Remove the drive end cap Remove the armature and thrust washer if so equipped from inside the starter frame Remove the brush carrier assembly from the frame Style B starters Style A End Cap Brush Replacement 1 Remove the brush springs from the pockets in the brush holder See Figure 8 35 Remove the self tapping screws negative brushes and plastic brush holder Remove
167. ging System 8 19 Section 8 Electrical System and Components Troubleshooting Guide 15 20 25 amp Battery Charging Systems When problems occur in keeping the battery charged or the battery charges at too high a rate the problem can usually be found somewhere in the charging system or with the battery NOTE Always zero ohmmeter on each scale before testing to ensure accurate readings Voltage tests should be made with the engine running at 3600 RPM no load The battery must be good and fully charged No Charge to Battery Battery Continuously Charges at High Rate 8 20 Trace B lead from rectifier regulator to key switch or other accessible connection Disconnect it from switch or connection Connect an ammeter from loose end of B lead to positive terminal of battery Connect DC voltmeter from loose end of B lead to negative terminal of battery With engine running at 3600 RPM read voltage on voltmeter If voltage is 13 8 volts or more place a minimum load of 5 amps on battery to reduce voltage Observe ammeter NOTE Turn on lights if 60 watts or more Or place a 2 5 ohm 100 watt resistor across battery terminals Remove connector from rectifier regulator With engine running at 3600 RPM measure AC voltage across stator leads using an AC voltmeter With engine stopped measure the resistance 3a across stator leads using an ohmmeter With the engine stopped measure the resistance from each s
168. gure 8 50 Removing Retaining Ring 11 Remove the retainer from the armature shaft 12 Remove the drive pinion assembly from the Save the stop collar armature NOTE Do not reuse the old retainer 13 Clean the parts as required NOTE Do not soak the armature or use solvent when cleaning Wipe clean using a soft cloth or use compressed air Plunger Spring Armature Frame amp Field Washer Brush Holder Nut CE Frame Screw Bolt Figure 8 51 Delco Remy Starter 8 31 Section 8 Electrical System and Components Inspection Commutator O D Drive Pinion Check and inspect the following areas a The pinion teeth for abnormal wear or damage b The surface between the pinion and the clutch mechanism for nicks or irregularities which could cause seal damage c Check the drive clutch by holding the clutch Mica Insulation housing and rotating the pinion The pinion should rotate in one direction only Figure 8 53 Commutator Mica Inspection Brushes and Springs o Inspect both the springs and brushes for wear fatigue l or damage Measure the length of each brush The minimum length for each brush is 7 6 mm 0 300 in See Figure 8 52 Replace the brushes if they are worn undersize or their condition is questionable Use an ohmmeter set to the Rx1 scale Touch the probes between two different segments of the commutator and check for continuity See Figure 8 54 Test all the segments Con
169. h and observe if a minimum of 7 volts is present If voltage is between 7 and 14 turn key switch off and connect an ohmmeter between the terminals on the pump to check for continuity a lf there was no continuity between the pump terminals replace the fuel pump b Ifthe voltage was below 7 test the wiring harness and relay as covered in the Electrical Relay section If voltage at the plug was good and there was continuity across the pump terminals reconnect the plug to the pump making sure you have a good connection Turn on the key switch and listen for the pump to activate a If the pump starts repeat steps 1 and 2 to verify correct pressure b Ifthe pump still does not operate replace it 5B 20 Fuel Pressure Regulator Figure 5B 27 External Fuel Pressure Regulators with Base Figure 5B 28 Internal Fuel Pressure Regulator General The fuel pressure regulator assembly maintains the required operating system pressure of 39 psi 3 A rubber fiber diaphragm see Figure 5B 29 divides the regulator into two separate sections the fuel chamber and the pressure regulating chamber The pressure regulating spring presses against the valve holder part of the diaphragm pressing the valve against the valve seat The combination of atmospheric pressure and regulating spring tension equals the desired operating pressure Any time the fuel pressure against the bottom of the diaphragm exceeds the desired t
170. h is installed in the breather cover See Figure 6 8 Oil Sentry Switch d j E Breather Cover Figure 6 8 Location of Oil Sentry Switch or pipe plug On engines not equipped with Oil Sentry the installation hole is sealed with a 1 8 27 N P T F pipe plug To install the switch follow these steps 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the threads of the switch 2 Install the switch into the tapped hole in the breather cover See Figure 6 8 3 Torque the switch to 4 5 N m 40 in Ib Testing Compressed air a pressure regulator pressure gauge and a continuity tester are required to test the switch 1 Connect the continuity tester across the blade terminal and the metal case of the switch With 0 psi pressure applied to the switch the tester should indicate continuity switch closed Section Lubrication Syste the pressure increases through the range of 6 m Gradually increase the pressure to the switch As 3 0 5 0 psi the tester should indicate a change to no continuity switch open The switch should remain open as the pressure is increased to 90 psi maximum Gradually decrease the pressure through the range of 3 0 5 0 psi The tester should indicate a change to continuity switch closed down to 0 psi Replace the switch if it does not operate as specified 6 5 Section 6 Lubrication System 6 6 CH18 745 Section 7 Retractable
171. harge ignites spontaneously from heat and pressure shortly after ignition This creates two flame fronts which meet and explode to create extreme hammering pressures on a specific area of the piston Detonation generally occurs from using low octane fuels Preignition or ignition of the fuel charge before the timed spark can cause damage similar to detonation Preignition damage is often more severe than detonation damage Preignition is caused by a hot spot in the combustion chamber from sources such as glowing carbon deposits blocked cooling fins an improperly seated valve or wrong spark plug s See Figure 10 8 for some common types of piston and ring damage Tis d tM e j Ip T mr LU d 4 1 T i Au watt LIP to Scored Piston and Rings 10 9 Section 10 Inspection and Reconditioning Replacement pistons are available in STD bore size and in 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize Replacement pistons include new piston ring sets and new piston pins Replacement ring sets are also available separately for STD 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize pistons Always use new piston rings when installing pistons Never use old rings Some important points to remember when servicing piston rings 1 The cylinder bore must be deglazed before service ring sets are used 2 Ifthe cylinder bore does not need reboring and if the old piston is within wear limits and free of score or scuff
172. he drive components Style A Drive Service 1 Remove the starter from the engine and remove the dust cover 2 Hold the drive pinion in a vice with soft jaws when removing or installing the stop nut The armature will rotate with the nut until the drive pinion stops against internal spacers NOTE Do not overtighten the vise as this can distort the drive pinion 3 Remove the stop nut stop gear spacer anti drift spring dust cover spacer and drive pinion 4 Clean the splines on drive shaft thoroughly with solvent Dry the splines thoroughly 5 Apply a small amount of Kohler electric starter drive lubricant Part No 52 357 01 S to the splines The use of other lubricants may cause the drive pinion to stick or bind 6 Apply a small amount of Loctite No 271 to the stop nut threads Section 8 Electrical System and Components 7 Install the drive pinion dust cover spacer anti drift spring stop gear spacer and stop nut Torque the stop nut to 17 0 19 2 N m 150 170 in Ib Reinstall the dust cover Style A CS 9 Dust Cover Stop Nut Stop Gear Spacer EJ Anti Drift Spring Style B Dust Cover Retaining Ring Spring Retainer Anti Drift Spring Dust Cover Spacer e Drive Pinion ini Drive Nut Collar C2 Dust Cover Spacer Drive Pinion Style A Style B Figure 8 30 Inertia Drive Electric Starter 8 23
173. he exhaust system and attaching hardware from the engine On engines equipped with a port liner remove it now Remove Air Cleaner Assembly 1 Unhook the latches or loosen the knob and remove the cover Refer to Section 4 2 Remove the wing nut from the element cover 3 Remove the element cover the air cleaner element with precleaner and the stud seal Section 9 Disassembly 4 Remove the hex flange screws securing the bracket and base See Figure 9 8 Two additional rear screws must be removed if the engine contains a rear air cleaner support bracket See Figure 9 9 Figure 9 9 Rear Air Cleaner Bracket Screws 5 Remove the bracket then remove the base and gasket while carefully pulling the rubber breather tube through the base See Figure 9 10 Figure 9 10 Removing Breather Tube from Base 9 3 Section 9 Disassembly Figure 9 11 Removing Tube from Breather Cover Figure 9 13 Disconnecting Pulse Line from Crankcase 6 Remove the rubber breather tube from the breather cover See Figure 9 11 Remove Fuel Pump A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine n
174. he wiring harnesses from the engine and equipment are joined Separate the connectors and remove the white kill lead from the engine connector Rejoin the connectors and position or insulate the kill lead terminal so it cannot touch ground Try to start the engine to verify whether the reported problem is still present a Ifthe problem is gone the electrical system on the unit is suspect Check the key switch wires connections safety interlocks etc b If the problem persists the condition is associated with the ignition or electrical system of the engine Leave the kill lead isolated until all testing is completed 8 8 NOTE If the engine starts or runs during any of the testing you may need to ground the kill lead to shut it down Because you have interrupted the kill circuit it may not stop using the switch Test 2 Test for spark 1 With the engine stopped disconnect one spark plug lead Connect the spark plug lead to post terminal of spark tester SPX Part No KO1046 formerly Kohler Part No 24 455 02 S and attach tester clip to a good engine ground NOTE lf two testers are available testing can be performed simultaneously for both cylinders However if only one tester is available two individual tests must be performed The side not being tested must have the spark plug lead connected or grounded Do not crank the engine or perform tests with one spark plug lead disconnected and not grounded or
175. her wave Washer flat 3 opring choke return Nut M5x0 8 lock Figure 11 83 Throttle Choke Control Bracket Detail Install Oil Sentry If So Equipped 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the threads of the Oil Sentry switch and install it into the breather cover See Figure 11 84 Torque to 4 5 N m 40 in Ib 2 Connect the wire lead green to the Oil Sentry terminal Install Control Panel If So Equipped 1 Install the panel to the blower housing 2 Connect the throttle control cable or shaft 3 Connect the choke control cable to the control bracket 4 Connect the Oil Sentry indicator light wires 11 25 Section 11 Reassembly Install Valve Covers Three valve cover designs have been used The earliest type used a gasket and RTV sealant between the cover and sealing surface of the cylinder head The second type had a black O Ring installed in a groove on the underside of the cover and may have metal spacers in the bolt holes The newest design uses a brown O Ring and the bolt hole spacers are molded in place The tightening torque differs between gasket and O Ring style covers Kits are available for converting to the latest O Ring type covers Differences are pointed out in the following installation steps NOTE Do not scrape old RTV sealant if used off the sealing surface of the cylinder head as this could cause damage and result in leaks The
176. ier and recheck gap after tightening b If the gap is incorrect or the module was loosened or replaced adjust the gap as follows 1 Turn the flywheel magnet away from the module position 2 Attach the module to the mounting legs pull it away from the flywheel and snug the screws to hold it temporarily 3 Rotate the flywheel so the magnet is centered under the module 8 10 4 Position a 0 33 mm 0 013 in feeler gauge between the magnet and all three legs of the module The ignition module air gap is critical to proper system performance Do not attempt to set it with a business card or folded microfiche card use the feeler gauge specified A 0 33 mm 0 013 in feeler gauge is recommended because the gap has a tendency to close slightly as the module mounting screws are tightened e Loosen the mounting screws allow the magnet to pull the module down against the feeler gauge and retighten the mounting screws m Rotate the flywheel to remove the feeler gauge position the magnet back under the module and recheck that the specified gap minimum of 0 28 mm 0 011 in exists under each leg of the module When you are certain the gap is correct torque the module mounting screws to 4 0 N m 35 in Ib On a twin cylinder engine repeat these 6 steps to set the opposite side ignition module 6 Reattach the lead wires to the ignition module s noting if resistance is felt indicating a snug fit between
177. ill need a DC voltmeter Perform the following steps see Figure 8 2 1 Connect the voltmeter across the battery terminals 2 Crank the engine If the battery drops below 9 volts while cranking the battery is too small discharged or faulty Figure 8 2 Battery Voltage Test 8 3 Section 8 Electrical System and Components Electronic CD Ignition Systems Carburetor Solenoid CH Ignition Starter and Oil Module Carburetor Pressure Advance Solenoid Green Safety Module Optional Cil Pressure EN B and Carburetor Solenoid Input voie B Rectifier White Regulator Spark Safety Input Plugs Figure 8 3 Electronic CD Ignition System For Customer Connected Tractor Applications The SMART SPARK ignition system used on some Operation of CD Ignition Systems models is an advanced version of the CD ignition system used on other CH engines Its operation can A Capacitive Discharge with Fixed Timing be best understood by first understanding the standard This system Figure 8 3 consists of the following system and how it works Since both systems will components continue in use it is advantageous to understand them both The operation of the standard system is e Amagnet assembly which is permanently affixed explained first then expanded to cover SMART to the flywheel SPARK Two electronic capacitive discharge ignition modules which mount on the engine crankcase Figure 8 4 Ak
178. ill switch or key switch which grounds the modules to stop the engine Two spark plugs 8 4 Kill Switch or Off Position of Key Switch 0 28 0 33 mm a Section 8 Electrical System and Components 0 011 0 013 in Air Gap la Ignition Modules y _ Spark Plug Magnet Flywheel Figure 8 4 Capacitive Discharge Fixed Timing Ignition System The timing of the spark is controlled by the location of the flywheel magnet group as referenced to engine top dead center Spark Plug Figure 8 5 Capacitive Discharge Ignition Module Schematic Operation As the flywheel rotates the magnet grouping passes the input coil L1 The corresponding magnetic field induces energy into the input coil L1 The resultant pulse is rectified by D1 and charges capacitor C1 As the magnet assembly completes its pass it activates the triggering device L2 which causes the semiconductor switch SCS to turn on With the device switch ON the charging capacitor C1 is directly connected across the primary P of the output transformer T1 As the capacitor discharges the current initiates a fast rising flux field in the transformer core A high voltage pulse is generated from this action into the secondary winding of the transformer This pulse is delivered to the spark plug gap lonization of the gap occurs resulting in an arc at the plug electrodes This spark ignites the fuel air mixture in the combustion cha
179. impurities Make sure the engine is level when filling or checking oil Change the oil as follows 1 Cleanthe areas around one of the oil drain plugs oil fill cap and dipstick 2 Remove one of the oil drain plugs A drain plug is located on either side of the crankcase one is adjacent to and below the oil filter the other is below the starter See Figure 6 4 Figure 6 4 Location of Oil Drains Section 6 Lubrication System 3 Allow all the oil to drain and then reinstall the drain 1 Cleanthe areas around the drain plug oil filter oil plug Torque to 13 6 N m 10 ft Ib fill cap and dipstick 4 Remove the oil fill cap and fill the engine with the 2 Remove one of the oil drain plugs A drain plug is proper oil to the F mark on the dipstick Always located on either side of the crankcase one is check the oil level with the dipstick before adding adjacent to and below the oil filter the other is more oil below the starter 3 Allow all oil to drain and then reinstall the drain plug Torque to 13 6 N m 10 ft Ib 4 Remove the old filter and wipe off the filter adapter with a clean cloth 5 Place a new replacement filter in a shallow pan with the open end up Pour new oil of the proper type in through the threaded center hole Stop pouring when the oil reaches the bottom of the threads Allow a minute or two for the oil to be absorbed by the filter material 6 Apply a thin film of clean oil to the rubber
180. in Section 11 Reassembly One end ofthe cross shaft protrudes through the crankcase The rotating action of the cross shaft Governor is transmitted to the throttle lever of the carburetor through the external throttle linkage See Figure General 5 9 The governor is designed to hold the engine speed constant under changing load conditions Most e When the engine is at rest and the throttle is in engines are equipped with a centrifugal flyweight the fast position the tension of the governor mechanical governor Some engines utilize an optional spring holds the throttle plate open When the electronic governor which is shown and covered on engine is operating the governor gear assembly page 5 12 and 5 13 The governor gear flyweight is rotating The force applied by the regulating pin mechanism of the mechanical governor is mounted against the cross shaft tends to close the throttle inside the crankcase and is driven off the gear on the plate The governor spring tension and the force camshaft This governor design works as follows applied by the regulating pin balance each other during operation to maintain engine speed Centrifugal force acting on the rotating governor gear assembly causes the flyweights to move e When load is applied and the engine speed and outward as speed increases Governor spring governor gear speed decreases the governor tension moves them inward as speed decreases spring tension moves the governor arm to o
181. ine leaking loose or pinched Restricted fuel line Loose leaking fuel enrichment hose Impco carburetor system Low power Ts 2 3 4 Air cleaner or exhaust system dirty restricted Low fuel Rich gas condition flooding through regulator a Dirty restricted valves in regulator b Damaged primary diaphragm in regulator No fuel a Electric lock off not opening filter blocked or restriction within fuel line b Leaking loose or cracked vacuum line from carburetor to regulator c Leaking or loose intake system components d Regulator primary valve not opening e Secondary or vacuum lock off diaphragm within regulator leaking f Low pressure rubber hose kinked g Frozen regulator Improper ignition timing Loose incorrect throttle lever clamp bracket positioning Loose or incorrectly positioned high speed throttle plate stop Engine runs lean 1 CDU inco p Electrical problem causing intermittent lock off operation or lock off is faulty Filter in lock off dirty or restricted Restriction in fuel system Idle holes plugged dirt in fuel delivery channels Carburetor fuel circuit restriction Loose leaking fuel enrichment hose Impco carburetor system High fuel consumption 1 Fuel leak Check lines connections and system components for leaks with soapy water Fix any leaks immediately Incorrectly set regulator or leakage from valves in regulator Readjust servic
182. ing compensation for changes in overall engine condition and operating environment so it will be able to maintain the ideal air fuel ratio of 14 7 1 The system requires a minimum engine oil temperature greater than 55 C 130 F to properly adapt These adaptive values are maintained as long as the ECU is powered up by the battery During certain operating periods such as cold starts warm up acceleration etc an air fuel ratio richer than 14 7 1 is required and the system operates in an open loop mode In open loop operation the monitoring of exhaust gases output is not used and the controlling adjustments are based on the primary sensor signals and programmed maps only The system operates open loop whenever the three conditions for closed loop operation above are not being met 5B 3 Section 5B EFI Fuel System Important Service Notes Cleanliness is essential and must be maintained at all times when servicing or working on the EFI system Dirt even in small quantities can cause significant problems Clean any joint or fitting with parts cleaning solvent before opening to prevent dirt from entering the system e Always depressurize the fuel system through the test valve in fuel rail before disconnecting or servicing any fuel system components See fuel warning on page 5B 2 e Never attempt to service any fuel system component while engine is running or ignition switch is on Donotuse compresse
183. ing fins or cooling shrouds clogged Excessive engine load Low crankcase oil level High crankcase oil level Faulty carburetor Lean fuel mixture SMART SPARK malfunction applicable models Engine Knocks QUOI QUOS e ot Excessive engine load Low crankcase oil level Old or improper fuel Internal wear or damage Hydraulic lifter malfunction Quality of fuel Incorrect grade of oil Engine Loses Power 10 11 12 3 2 O OO WOO ow C9 TO c Low crankcase oil level High crankcase oil level Dirty air cleaner element Dirt or water in the fuel system Excessive engine load Engine overheated Faulty spark plugs Low compression Exhaust restriction SMART SPARK malfunction applicable models Low battery Incorrect governor setting Engine Uses Excessive Amount of Oil oo c O oo T e Incorrect oil viscosity type Clogged or improperly assembled breather Breather reed broken Worn or broken piston rings Worn cylinder bore Worn valve stems valve guides Crankcase overfilled Blown head gasket overheated Oil Leaks from Oil Seals Gaskets 1 a 3 4 o Crankcase breather is clogged or inoperative Breather reed broken Loose or improperly torqued fasteners Piston blowby or leaky valves Restricted exhaust External Engine Inspection Before cleaning or disassembling the engine make a thorough inspection of its external appearance and condition This inspect
184. interruption until the proper height is obtained Otherwise the frictional heat from the engaging threads may cause the locking compound to set up prematurely The studs closest to the lifters must have an exposed height of 75 mm 2 15 16 in The studs furthest from the lifters must have an exposed height of 69 mm 2 3 4 in c Remove the nuts and repeat the procedure as required 11 12 Figure 11 43 Installing New Mounting Studs to Specified Height 4 Check that the dowel pins are in place and install a new cylinder head gasket printing up Install the cylinder head Match the numbers on the cylinder heads and the crankcase See Figure 11 36 Make sure the head is flat on the gasket and dowel pins Lightly lubricate the exposed upper threads of the studs with engine oil Install a flat washer and hex nut onto each of the mounting studs Torque the hex nuts in two stages first to 16 9 N m 150 in Ib then finally to 33 9 N m 300 in Ib following the sequence in Figure 11 42 Figure 11 44 Torquing the Cylinder Head Mounting Nuts Stud Design Install Push Rods and Rocker Arms Early models used hollow push rods with special Section 11 Reassembly NOTE Push rods should always be installed in the same position as before disassembly 1 Note the mark or tag identifying the push rod as either intake or exhaust and cylinder 1 or 2 Dip the ends of the push rods in engine oil and insta
185. into the perimeter of the closure plate Insert the drive end of a 1 2 breaker bar between the top splitting tab and the crankcase Hold the handle horizontal and pull toward you to break the RTV seal If necessary pry at the bottom tabs also See Figures 9 62 and 9 63 Do not pry on the sealing surfaces as this could cause leaks Carefully pull closure plate from crankcase Figure 9 59 Removing Backing Plates and Stator Wire Bracket 2 Remove the two hex head screws and stator See Figure 9 60 Note the routing of the stator lead in the channel Figure 9 60 Removing Stator Remove Closure Plate Assembly 1 Remove the ten hex flange screws securing the closure plate to the crankcase See Figure 9 61 Figure 9 63 Breaking Seal on Top Splitting Tab Governor Gear Assembly The governor gear assembly is located inside the closure plate If service is required refer to the service procedures under Governor Gear Assembly in Section 10 Oil Pump Assembly The oil pump is mounted to the inside of the closure plate If service is required refer to the service procedures under Oil Pump Assembly in Section 10 Figure 9 61 Removing the Ten Closure Plate Fasteners 9 16 Section 9 Disassembly Remove Camshaft 1 Remove the camshaft and shim See Figure 9 64 Figure 9 66 Mark End Cap with Cylinder Number Before Removal E Figure 9 64 Removing Camshaft Note Shim NOTE The cylinder
186. inuously grounded so the pump is immediately codes and run the engine to check if any fault activated and pressurizes the system Activation of the codes reappear ignition coils and injectors is controlled by the ECU which grounds their respective circuits at the proper To Replace Oxygen Sensor times 1 Disconnect the oxygen sensor connector from wiring harness Service A malfunctioning relay can result in starting or 2 Loosen and remove the oxygen sensor from the operating difficulties The relay and related wiring can exhaust manifold muffler assembly be tested as follows 3 Apply anti seize compound sparingly to threads of 1 Disconnect the relay connector plug from the new oxygen sensor if none already exists DO relay NOT get any on the tip as it will contaminate the sensor Install sensor and torque to 50 60 Mm 2 Connect black lead of VOA meter to a chassis 37 44 ft Ib ground location Connect red lead to the 86 terminal in relay connector see Figure 5B 14 4 Reconnect the lead to wiring harness connector Set meter to test resistance Rx1 Turn ignition Make sure it can not contact hot surfaces moving switch from off to on Meter should indicate parts etc continuity ground circuit is completed for 1 to 3 l seconds Turn key switch back off 5 Test run the engine 5B 13 Section 5B EFI Fuel System Terminal 87 Feed To Ignition Coils Fuel Injectors and Fuel Pump Terminal 85 Igni
187. ion can give clues to what might be found inside the engine and the cause when it is disassembled Check for buildup of dirt and debris on the crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas are causes of higher operating temperatures and overheating Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or improperly assembled breather worn damaged seals and gaskets or loose or improperly torqued fasteners Check the air cleaner cover and base for damage or indications of improper fit and seal Check the air cleaner element Look for holes tears cracked or damaged sealing surfaces or other damage that could allow unfiltered air into the engine Also note if the element is dirty or clogged These could indicate that the engine has been under serviced Check the carburetor throat for dirt Dirt in the throat is further indication that the air cleaner is not functioning properly Check the oil level Note if the oil level is within the operating range on the dipstick or if it is low or overfilled e Check the condition of the oil Drain the oil into a container the oil should flow freely Check for metal chips and other foreign particles Sludge is a natural by product of combustion a small accumulation is normal Excessive sludge formation could indicate overrich carburetion weak ignition overextended oil change int
188. is adjusted by repositioning the governor spring in the holes of the governor lever If speed surging occurs with a change in engine load the governor is set too sensitive If a big drop in speed occurs when normal load is applied the governor should be set for greater sensitivity See Figure 5 10 and adjust as follows 1 To increase the sensitivity move the spring closer to the governor cross shaft 2 To decrease the sensitivity move the spring away from the governor cross shaft Section 5 Fuel System and Governor Figure 5 10 Governor Sensitivity Adjustments High Speed RPM Adjustment Refer to Figure 5 11 1 With the engine running move the throttle control to fast Use a tachometer to check the RPM speed 2 Loosen the lock nut on high speed adjusting screw Turn the screw outward to decrease or inward to increase the RPM speed Check RPM with a tachometer 3 When the desired RPM speed is obtained retighten the lock nut NOTE When the throttle and choke control cables are routed side by side especially under a single clamp there must be a small gap between the cables to prevent internal binding After the high speed setting has been completed check that there is a gap of at least 0 5 mm 0 020 in between the control cables 5 11 Section 5 Fuel System and Governor Left Side Pull Throttle Control Lever 2 Choke Control Lever 1 Choke Control Cable Kill Switch Choke Linkage Throttle
189. itch Black dabei J Diode 3 Amp 70 Watt anf Fuse 1 Flywheel Optional z Yellow ywheel Stator Oil Sentry Optional m ROO Switch Ammeter z Indicator Light Optional Cil Sentry Switch KEN Shutdown gt Gi B E 12 V Battery Solenoid Y Starter Figure 8 18 Wiring Diagram 3 amp Unregulated Battery Charging System 70 Watt Lighting 8 15 Section 8 Electrical System and Components Lighting Lead Yellow Diode Charging Lead Black Figure 8 19 3 amp 70 Watt Stator Stator The stator is mounted on the crankcase behind the flywheel Follow the procedures in Section 9 Disassembly and Section 11 Reassembly if stator replacement is necessary Rectifier Regulator The rectifier regulator is mounted on the blower housing See Figure 8 20 To replace it disconnect the plug s remove the two mounting screws and ground wire or metal grounding strap NOTE When installing the rectifier regulator take note of the terminal markings and install the plug s accordingly Rectifier Regulator j Ground Strap or lead Figure 8 20 Rectifier Regulator Testing of the rectifier regulator may be performed as follows using the Rectifier Regulator Tester SPX Part No KO3221 formerly Kohler Part No 25 761 20 S 8 16 3 Amp Charging Stator Lighting Stator To Test NOTE Disconnect all electrical connections attached to the rectifier
190. l or oil in the combustion chamber Excess fuel could be caused by a restricted air cleaner a carburetor problem or operating the engine with too much choke Oil in the combustion chamber is usually caused by a restricted air cleaner a breather problem worn piston rings or valve guides Overheated Chalky white deposits indicate very high combustion temperatures This condition is usually accompanied by excessive gap erosion Lean carburetor settings an intake air leak or incorrect spark timing are normal causes for high combustion temperatures Battery General A 12 volt battery with 400 cold cranking amps is generally recommended for starting in all conditions A smaller capacity battery is often sufficient if an application is started only in warmer temperatures Refer to the following table for minimum capacities cca based on anticipated ambient temperatures The actual cold cranking requirement depends on engine size application and starting temperatures The cranking requirements increase as temperatures decrease and battery capacity shrinks Refer also to the operating instructions of the equipment being this engine powers for specific battery requirements Battery Size Recommendations Above 32 F 0 C Battery Required 200 cca minimum 250 cca minimum O F to 32 F 18 C to 0 C 5 F to O F 21 C to 18 C 10 F 23 C or below 300 cca minimum 400 cca minimum If the battery charge is insu
191. l the breather hose in the hole in the bracket 5 Install the air cleaner components as described in Section 4 Install Muffler 1 Install the port liners if equipped Install the muffler and attaching hardware to the muffler bracket Torque screws to 9 9 N m 88 in Ib Tm UE Dech e 2 Install the hex flange nuts to the exhaust studs Figure 11 89 Fuel Inlet Line Detail Torque hex flange nuts to 24 4 N m 216 in Ib 11 27 Section 11 Reassembly Install Oil Cooler 1 Reinstall the oil cooler on the engine if equipped Install a new gasket between the cooler and the closure plate Torque nipple adapter to 27 N m 20 ft Ib See Figure 11 92 Figure 11 94 Hand Tightening Oil Filter 4 Install the oil drain plugs See Figure 11 95 Torque the plugs to 13 6 N m 10 ft Ib NOTE Make sure that both oil drain plugs are Filter Nipple installed and torqued to the above specifications to prevent oil leakage Figure 11 92 Torquing Oil Install Oil Filter and Fill Crankcase with Oil 1 Prefill a new oil filter following the instructions in Section 6 2 Apply a thin film of clean engine oil to the rubber gasket on the oil filter and thread the filter onto the adapter nipple See Figure 11 93 Figure 11 95 Reinstall and Torque Both Oil Drain Plugs 5 Add oil to bring the level up to F mark and reinstall the dipstick See Figure 11 96 Figure 11 93 Installing New Oil Filter
192. lange joints at the exhaust ports become suspect With sensor still hot minimum of 400 C 752 F switch meter to the Rx1K or Rx2K scale and check the resistance between the sensor lead and sensor case It should be less than 2 0 KO a Ifthe resistance is less than 2 0 KO go to Step 4 b If the resistance is greater than 2 0 KQ the oxygen sensor is bad replace it Allow the sensor to cool less than 60 C 140 F and retest the resistance with the meter set on the Rx1M scale With sensor cool the resistance should be greater than 1 0 MQ a If the resistance is greater than 1 0 MQ go to Step 5 b Ifthe resistance is less than 1 0 MQ the sensor is bad replace it With the oxygen sensor disconnected and engine not running disconnect the main harness connector from the ECU and set the meter to the Rx1 scale Check the circuit continuity as follows 35 Pin MA 1 7 Metal Cased ECU Check for continuity from pin 9 of the ECU connector see page 5B 28 to the shell of the oxygen sensor and from pin 10 to the sensor connecior terminal of the main harness Both tests should indicate continuity 24 Pin MSE 1 0 Plastic Cased ECU Check for continuity from pin 15 of the ECU connector see page 5B 31 to the shell of the oxygen sensor and from pin 11 to the sensor connector terminal of the main harness Both tests should indicate continuity 32 Pin MSE 1 1 Plastic Cased ECU Check
193. ll making sure that each push rod ball seats in its hydraulic lifter socket See Figure 11 45 Figure 11 45 Install Push Rods in Their Original Position 2 Apply grease to the contact surfaces of the rocker arms and rocker arm pivots Install the rocker arms and rocker arm pivots on one cylinder head and start the two hex flange screws See Figure 11 46 Figure 11 46 Torquing Rocker Arm Screws 3 Torque the hex flange screws to 11 3 N m 100 in Ib Repeat for the other rocker arm 4 Use a spanner wrench or rocker arm lifting tool rocker arms They are not interchangeable with the later current style solid push rods and associated rocker arms Do not mix these A replacement kit is available with solid components see Section 2 to lift the rocker arms and position the push rods underneath See Figure 11 47 11 13 Section 11 Reassembly 5 Repeat the above steps for the remaining cylinder Do not interchange parts from the cylinder heads Figure 11 47 Using Spanner Wrench to Lift Rocker Arm Over Push Rod 6 Rotate the crankshaft to check for free operation of the valve train Check the clearance between the valve spring coils at full lift Minimum allowable clearance is 0 25 mm 0 010 in Install Spark Plugs 1 Use new Champion or equivalent spark plugs 2 Setthe gap at 0 76 mm 0 030 in 3 Install new plugs and torque to 24 4 29 8 N m 18 22 ft Ib See Figure 11 48
194. ll Closure Plate Assembly RTV sealant is used as a gasket between the closure plate and the crankcase Refer to Section 2 for a listing of approved sealants Always use fresh sealant Using outdated sealant can result in leakage 1 Be sure the sealing surfaces have been cleaned and prepared as described at the beginning of Section 10 or in Service Bulletin 252 2 Check to make sure that there are no nicks or burrs on the sealing surfaces of the closure plate or crankcase Section 11 Reassembly 3 Apply a 1 5 mm 1 16 in bead of sealant to the 6 Install the ten hex flange screws securing the sealing surface of the closure plate See Figure closure plate to the crankcase Torque fasteners 11 19 for sealant pattern in the sequence shown in Figure 11 21 to 24 4 N m 216 in Ib On some engines one of the ten mounting screws is plated The plated screw is typically installed in the 6 hole shown in Figure 11 21 Figure 11 21 Closure Plate Fastener Torque Sequence Figure 11 19 Closure Plate Sealant Pattern 4 Make sure the end of the governor cross shaft is lying against the bottom of cylinder 1 inside the crankcase See Figure 11 13 5 Install the closure plate to the crankcase Carefully seat the camshaft and the crankshaft into their mating bearings Rotate the crankshaft slightly to help engage the oil pump and governor gear meshes See Figure 11 20 Figure 11 22 Torquing Closure Plate Fasteners n Ins
195. llowing procedure Above 10 50 F SAE 30 1 Remove capscrews 2 from clutch yoke and 17 8 C 0 to 10 C 50 F SAE 20 remove spacers Below 17 8T 0 F SAE 10 S Adjustment Slight readjustment may be needed after a few hours on a new clutch to accommodate normal run in wear Firm pressure should be required to engage clutch 40 45 pounds pull at lever handle Readjust if clutch slips and overheats or if clutch handle jumps out after 5 engagement Use the following procedure l Remove cross shaft 3 Remove housing bolts 4 and slide housing off 4 Loosen bolts securing clutch assembly to crankshaft then remove locking screw Pull clutch assembly off 6 To replace clutch simply turn adjusting collar off 1 Release clutch and remove nameplate Using a and remove plate large screwdriver turn adjusting ring clockwise one notch at a time until firm pressure is required to engage clutch See Figure 12 2 Adjusting ring is spring loaded and does not have to be loosened before adjustment is made Do not attempt to pry or force spring lock away from the ring Reverse procedure for reassembly Adjust and lubricate following previous instructions Figure 12 2 Adjusting Clutch 12 2 KOHLER EISE FOR SALES AND SERVICE INFORMATION IN U S AND CANADA CALL 1 800 544 2444 ENGINE DIVISION KOHLER CO KOHLER WISCONSIN 53044 FORMNO TP 2428 B ISSUED 4 92 REVISED 6 04 MAILED 7 04 LITHO IN U
196. m 5 Fuel pump 95 Pin MA 1 7 Metal Cased ECU Circuits 28 41 and 41A Possible causes for high fuel system pressure 24 Pin MSE 1 0 Plastic Cased ECU Circuits 1 Pressure regulator 18 85 30 and 87 2 Fuel return line plugged or restricted 32 Pin MSE 1 1 Plastic Cased ECU Circuits 28 85 30 and 87 Diagnostic Aid 10 BASIC ENGINE cranks but will 3 Relay not run 4 ECU grounds 5 ECU Possible causes 1 Refer to basic engine troubleshooting charts within service manual sections 3 5 and 8 5B 45 Section 5B EFI Fuel System 5B 46 CH18 745 Section 6 Lubrication System General This engine uses a full pressure lubrication system This system delivers oil under pressure to the crankshaft camshaft and connecting rod bearing surfaces In addition to lubricating the bearing surfaces the lubrication system supplies oil to the hydraulic valve lifters A high efficiency gerotor pump is located in the closure plate The oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve limits the maximum pressure of the system Service The closure plate must be removed to service the oil pickup the pressure relief valve and the oil pump Refer to the appropriate procedures in Sections 9 and 10 Oil Recommendations Using the proper type and weight of oil in the crankcase is extremely important so is checking oil daily and changi
197. m allowable limit N A N A A N A N A N A N A A N A N A N A N A A P1260 Injector 1 Open Circuit P0261 Injector 1 Short Circuit to Ground P1263 Injector 2 Open Circuit Z de gt Jaa acteeen E P1651 Diagnostic Lamp Open Circuit P0262 Injector 1 Short Circuit to Battery Y N A N A N A N A N A N A N A N A N A N A N A N A N A N A Z u N 31 32 33 33 34 34 42 42 43 44 51 51 51 52 52 52 55 55 55 56 56 56 61 Note p DO ds Idle Switch not used Diagnostic of TPS Signal Implausible is disabled in code O Sensor Short to Battery diagnostic detection is disabled with SAS fuel cutoff calibrated out Air Temperature Sensor not used Temperature Sensor Signal Implausible diagnostic detection is calibrated out with TPLAUS set to 50 C System too Lean used to be O Sensor Short to Ground P0131 System too Rich used to be O Sensor Control at Lower Limit P0019 Obtainable only with ECU 24 584 28 S or later Will not blink out 5B 36 Code 21 Source Engine Speed Sensor Explanation ECU receiving inconsistent tooth count signals from speed sensor Expected Engine Response Possible misfire as ECU attempts to resynchronize during which time fuel and spark calculations are not made Possible Causes 1 Engine Speed Sensor Related a Sensor connector or wiring b Sensor loose or incorrect air gap c Flywheel ke
198. mber Capacitive Discharge with Electronic Spark D Advance SMART SPARK SMART SPARK equipped engines utilize an electronic capacitive discharge ignition system with electronic spark advance A typical application Figure 8 6 consists of the following components A magnet assembly which is permanently affixed to the flywheel Two electronic capacitive discharge ignition modules which mount on the engine crankcase Figure 8 6 A spark advance module which mounts to the engine shrouding Figure 8 7 A 12 volt battery which supplies current to the spark advance module A kill switch or key switch which grounds the spark advance module to stop the engine Two spark plugs 8 5 Section 8 Electrical System and Components Key Switch or Off 12 Volt Battery Position of Key Switch White Spark Advance Module Spark Plug NU Spark Plug T i i J 0 28 0 33 mm Ignition Module 0 011 0 013 in Air Gap Flywheel Figure 8 6 Capacitive Discharge Ignition System with Spark Advance The timing of the spark is controlled by the location of the flywheel magnet group as referenced to the engine top dead center and the delay created by the spark advance module E o i D Se o V 7 2V B 12 VDC Source Red Input Circuit Circuit T Coil Pulse Yellow Comparator P o Semi Conductor Switch Charge Reset Pump Circuit Figure 8 7 Block Diagram Spark Advance Module Op
199. mp to the lead Then trace the power source circuit back through the harness key switch etc looking for any poor connections or faulty circuits Disconnect all of the SAM leads isolating it from the engine Test the SAM with tester 25 761 21 S following the instructions following or use TT481 A provided with the tester If the SAM tests bad replace it Reattach the SAM leads verifying a snug fit at the ignition module terminals If any connections do not feel snug disconnect the lead lightly pinch the female terminal with a pliers and recheck the fit Seal the base of the ignition module connections with GE Novaguard G661 Kohler Part No 25 357 11 S or Fel Pro Lubri Sel dielectric compound The beads should overlap between the two connectionst to form a solid bridge of compound Do not put any compound inside the connectors t The 24 584 15 S ignition modules have a separator barrier between the terminals On these modules seal the base of the terminal if any portion of it is exposed but it is not necessary to have overlapping beads of sealant between the connections Test for spark Test 2 to be sure the system is working before you reinstall the blower housing If there is still a soark problem on one side replace that ignition module and recheck Spark Section 8 Electrical System and Components To Test NOTE SAM must be at room temperature to the touch when tested Disconnect ALL of the SAM lead
200. mps are available through your source of supply To replace the pulse pump follow these steps 1 Disconnect the fuel lines from the inlet and outlet fittings 2 Remove the hex flange screws securing the fuel pump 3 Remove the pulse line that connects the pump to the crankcase or valve cover Section 5 Fuel System and Governor NOTE On most models the pulse line is connected to a fitting on the crankcase while on early models it is connected to the valve cover 4 Install the new fuel pump using the hex flange screws Torque the hex flange screws to 2 3 N m 20 in Ib NOTE Make sure the orientation of the new pump is consistent with the removed pump Internal damage may occur if installed incorrectly 5 Connect the pulse line to the pulse fitting 6 Connect the fuel lines to the inlet and outlet fittings Replacing the Mechanical Pump The mechanical pump is an integral part of the valve cover assembly and not serviced separately See Figure 5 2 1 Disconnect the fuel lines from the inlet and outlet fittings 2 Follow the procedure for replacing the valve cover Sections 9 and 11 3 Reconnect the fuel lines to the inlet and outlet fittings hi m P Eur Figure 5 2 Mechanical Fuel Pump Carburetor _ Outlet Line to Mechanical Fuel Pump Inlet Line 5 3 Section 5 Fuel System and Governor Carburetor A WARNING Explosive Fuel Gasoline is e
201. n Permanent Battery Voltage Switched Ignition Voltage Safety Switch Throttle Position Sensor TPS and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor TPS Input Speed Sensor Input Speed Sensor Ground Oxygen Sensor Input Not Used Oxygen Sensor Ground if needed Diagnostic Line Throttle Position Supply Voltage Battery Ground Injector 1 Output Injector 2 Output Main Relay Output Malfunction Indicator Light MIL Not Used Tach Output if needed Not Used Ignition Coil 1 Output Ignition Coil 2 Output TPS Initialization Terminal 000000000000 000000000000 5B 31 Section 5B EFI Fuel System 92 Pin MSE 1 1 Plastic Cased ECU Systems Pin Function Permanent Battery Voltage Switched Battery Voltage TPS Set Auto Learn Initialization Terminal Throttle Position Sensor TPS and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor TPS Input Speed Sensor Input opeed Sensor Ground Not Used Not Used Not Used Injector 1 Output Injector 2 Output Not Used Diagnostic Line Throttle Position Temperature Sensor Supply Voltage Battery Ground Oxygen Sensor Input Not Used Not Used Not Used Not Used Safety Switch Input Not Used Not Used Main Relay Output Malfunction Indicator Light MIL Ignition Coil 1 Output Ignition Coil 2 Output Not Used 5B 32 co dH O wo P o M a DO Oo oo Oo OO oo o oo Oo oO 0
202. n Piston Pin Bore I D Mr ase 17 006 17 012 mm 0 6695 0 6698 in VI PORTE M 17 025 mm 0 6703 in Piston Pin O D Mr 16 995 17 000 mm 0 6691 0 6693 in VIERTE M 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance CHIS GH20 GH22 1624 66 EE 0 040 0 080 mm 0 0016 0 0031 in Suid 0 030 0 076 mm 0 0012 0 0030 in OH25 CHe6 Ren EE 0 025 0 048 mm 0 0010 0 0019 in Middle Compression Ring to Groove Side Clearance CHIS9 GCH20 GH22 624 CC sete ev eia coda d ek Eee 0 040 0 080 mm 0 0016 0 0031 in E EE 674 EE 0 030 0 076 mm 0 0012 0 0030 in EE CHO GEI 305745 ux visti a ie ancor od EE ai tara Cb redu atte 0 015 0 037 mm 0 0006 0 0015 in Oil Control Ring to Groove Side Clearance CIS GH2Z0 G22 624 06 iuter E Tut I aai Uma TELS 0 060 0 202 mm 0 0024 0 0080 in GH22 29 RE 0 046 0 196 mm 0 0018 0 0077 in OH25 CH26 6E 305745 iota aaa nde En en B ms ceni 0 026 0 176 mm 0 0010 0 0070 in Top and Center Compression Ring End Gap New Bore CH18 CH20 CH22 624 ech 0 25 0 45 mm 0 0098 0 01 77 in New Bore CH22 674 WE 0 18 0 46 mm 0 0071 0 0181 in New Bore CH25 CH26 CH 30 245 0 25 0 56 mm 0 0100 0 0224 in Used Bore Max CH18 CH20 CH22 624 CC 0 77 mm 0 030 in Used Bore Max CHDOI22IG Z4cch 0 80 mm 0 0315 in Used Bore Max CH
203. nd air cleaner assembly following the steps in Section 11 Reassembly Disassembly Disassemble the carburetor using the following steps See Figure 5 8 1 Remove the air cleaner breather hose and carburetor Refer to Section 9 Disassembly 2 Remove the four screws and carefully separate the air horn assembly from the carburetor body 3 Loosen the screw securing the float assembly to the air horn and remove the float float shaft and fuel inlet needle 4 Remove the slow jet from the carburetor body NOTE The main jet is a fixed jet and can be removed if required Fixed jets for high altitude are available 5 Remove the black cap on the end of the choke shaft only if it is necessary to inspect and clean the shaft spring 6 Remove the low idle speed adjusting screw and spring from the carburetor body 5 7 Section 5 Fuel System and Governor f In order to clean the off idle vent ports and bowl vent thoroughly use a good carburetor solvent like Gumout Blow clean compressed air through the idle adjusting needle hole Be careful to use a suitable shop rag to prevent debris from hitting someone Remove the preformed rubber gasket only if it is to be replaced If it is removed for any reason replace it Inspection Repair Carefully inspect all components and replace those that are worn or damaged 5 8 Inspect the carburetor body for cracks holes and other wear or damage Ins
204. necting rod and end cap into its appropriate cylinder bore as previously marked at disassembly Do not mix the end caps and connecting rods NOTE Proper orientation of the piston connecting rod assemblies inside the engine is extremely important Improper orientation can cause extensive wear or damage Be certain the pistons and connecting rods are assembled exactly as shown in Figure 11 8 1 Stagger the piston rings in the grooves until the end gaps are 120 apart The oil ring rails should also be staggered Cylinder 2 Cylinder 1 Figure 11 8 Piston Connecting Rod and End Cap Detail 2 Lubricate the cylinder bore piston and piston rings with engine oil Compress the rings of the 1 piston using a piston ring compressor Section 11 Reassembly 3 Lubricate the crankshaft journals and connecting rod bearing surfaces with engine oil 4 Make sure the Fly stamping on piston is facing towards the flywheel side of the engine Use a hammer with a rubber grip and gently tap the piston into the cylinder as shown in Figure 11 9 Be careful that the oil ring rails do not spring free between the bottom of the ring compressor and top of the cylinder A Sb F a Figure 11 9 Installing Piston Assembly Using Ring Compressor Tool 5 Install the inner rod cap to the connecting rod using the two hex flange screws Three different types of connecting rod bolts have been used and each has a different torque v
205. nents are all intact but you think there may be a problem with the adjustment follow Procedure A to check the setting If the governor lever was loosened or removed go immediately to Procedure B to perform the initial adjustment A Checking the Initial Adjustment 1 Unsnap the plastic linkage bushing attaching the throttle linkage to the governor lever See Figure 5B 37 Unhook the damper spring from the lever separate the linkage from the bushing and remove the bushing from the lever Mark the hole position and unhook the governor spring from the governor lever 5B 24 Throttle Gett IT eh Linkage Ss Figure 5B 37 Throttle Linkage Governor Lever Connection 2 Check if the engine has a high speed throttle stop screw installed in the manifold casting boss See Figure 5B 38 gu TE i High Speed Throttle Stop Screw oh Figure 5B 38 Throttle Details a On engines without a stop screw pivot the throttle shaft and plate assembly into the Full Throttle position Insert a 1 52 mm 0 060 in feeler gauge between the rear tang of the throttle shaft plate and the underside of the manifold boss Use a locking pliers needle nose works best to temporarily clamp the parts in this position See Figure 5B 39 i Feeler Gauge Figure 5B 39 Inserting Feeler Gauge Engines Without Stop Screw b On engines with a stop screw pivot the throttle shaft and plate into the Full Throttle position so the
206. nergizes but Turns Slowly Engine Check for excessively dirty or worn brushes and commutator Clean using a coarse cloth not emery cloth Replace brushes if excessively or unevenly worn Make sure the clutch or transmission is disengaged or placed in neutral This is especially important on equipment with hydrostatic resistance which could keep the engine from starting Check for seized engine components such as the bearings connecting rod and piston 8 22 Operation Inertia Drive Starters When power is applied to the starter the armature rotates As the armature rotates the drive pinion moves out on the splined drive shaft and into mesh with the flywheel ring gear When the pinion reaches the end of the drive shaft it rotates the flywheel and cranks the engine When the engine starts the flywheel rotates faster than the starter armature and drive pinion This moves the drive pinion out of mesh with the ring gear and into the retracted position When power is removed from the starter the armature stops rotating and the drive pinion is held in the retracted position by the anti drift spring Starter Drive Service Every 500 hours of operation or annually whichever occurs first clean and lubricate the splines on the starter drive shaft If the drive pinion is worn or has chipped or broken teeth it must be replaced See Figure 8 30 It is not necessary to completely disassemble the starter to service t
207. ng engine Accidental Keep hands feet hair and Engine components can get starting can cause severe injury clothing away from all moving extremely hot from operation To or death Before working on the parts to prevent injury Never prevent severe burns do not engine or equipment disable the operate the engine with covers touch these areas while the engine as follows 1 Disconnect the shrouds or guards removed engine is running or immediately spark plug lead s 2 Disconnect after it is turned off Never operate negative battery cable from the engine with heat shields or battery guards removed 1 1 Section 1 Safety and General Information A WARNING A WARNING Explosive Fuel can cause fires and severe burns Stop engine before filling fuel tank Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent AA WARNING Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Flammable Solvents Carburetor cleaners and solvents are extremely flammable Keep sparks flames
208. ng the oil and filter regularly Use high quality detergent oil of API American Petroleum Institute service class SG SH SJ or higher Select the viscosity based on the air temperature at the time of operation as shown in the following table RECOMMENDED SAE VISCOSITY GRADES TEMPERATURE RANGE EXPECTED BEFORE NEXT OIL CHANGE Use of synthetic oil having 5W 20 or 5W 30 rating is acceptable up to 4 C 40 F Synthetic oils will provide better starting in extreme cold below 23 C 10 F NOTE Using other than service class SG SH SJ or higher oil or extending oil change intervals longer than recommended can cause engine damage NOTE Synthetic oils meeting the listed classifications may be used with oil changes performed at the recommended intervals However to allow piston rings to properly seat a new or rebuilt engine should be operated for at least 50 hours using standard petroleum D based oil before switching to synthetic oil A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 6 1 S Figure 6 1 Oil Container Logo The top position of the symbol shows service class such as API SERVICE CLASS SJ The symbol may show additional categories such as SH SG CC or CD The center portion shows the viscosity grade such as SAE 10W 30 If the bottom portion shows Energy Conserving it means that oil is intended to improve fuel economy in passenger
209. nsor Related a Throttle plate position incorrect during Initialization procedure b TPS problem or malfunction 5B 39 Section 5B EFI Fuel System 3 Engine Wiring Harness Related a Difference in voltage between sensed voltage pin circuit 17 for metal cased ECU pin circuit 2 for plastic cased ECU and actual injector voltage circuit 45 45A b Problem in wiring harness c ECU to harness connection problem 4 Systems Related a Ignition spark plug plug wire ignition coil b Fuel fuel type quality injector fuel pressure fuel pump c Combustion air air cleaner dirty restricted intake leak throttle bores d Base engine problem rings valves e Exhaust system leak muffler flange oxygen sensor mounting boss etc f Fuelin the crankcase oll g Altitude h Blocked or restricted fuel return circuit to tank Code 42 Source Engine Cil Temperature Sensor Explanation Not sending proper signal to ECU Expected Engine Response Engine may be hard to start because ECU can t determine correct fuel mixture Possible Causes 1 Temperature Sensor Related a Sensor wiring or connection 2 Engine Wiring Harness Related 35 Pin MA 1 7 Metal Cased ECU a Pin circuits 14 and or 27A damaged wires connectors or routed near noisy signal coils alternator etc b ECU to harness connection problem 2 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU
210. ny time an injector is removed new replacement injectors include new O Rings Lubricate O Rings lightly with oil Torque the fuel rail and blower housing mounting screws to 3 9 N m 35 in Ib and the intake manifold and air cleaner mounting screws to 9 9 N m 88 in Ib Injector problems due to dirt or clogging are generally unlikely due to the design of the injectors the high fuel pressure and the detergent additives in the gasoline oymptoms that could be caused by dirty clogged injectors include rough idle hesitation stumble during acceleration or triggering of fault codes related to fuel delivery Injector clogging is usually caused by a buildup of deposits on the director plate restricting the flow of fuel resulting in a poor spray pattern Some contributing factors to injector clogging include higher Section 5B EFI Fuel System than normal operating temperatures short operating intervals and dirty incorrect or poor quality fuel Cleaning of clogged injectors is not recommended they should be replaced Additives and higher grades of fuel can be used as a preventative measure if clogging has been a problem Ignition System General A high voltage solid state battery ignition system is used with the EFI system The ECU controls the ignition output and timing through transistorized control of the primary current delivered to the coils Based on input from the speed sensor the ECU determines the correct firing
211. o bore clearance is the difference between the bore diameter and the piston diameter step 2 minus step 1 Flywheel Inspection Inspect the flywheel for cracks and the flywheel keyway for damage Replace the flywheel if it is cracked Replace the flywheel the crankshaft and the key if flywheel key is sheared or the keyway is damaged Inspect the ring gear for cracks or damage Kohler does not provide the ring gear as a serviceable part Replace the flywheel if the ring gear is damaged Cylinder Head and Valves Inspection and Service After cleaning check the flatness of the cylinder head and the corresponding top surface of the crankcase using a surface plate or piece of glass and feeler gauge as shown in Figure 10 5 The maximum allowable out of flatness is 0 076 mm 0 003 in Figure 10 5 Checking Cylinder Head Flatness Carefully inspect the valve mechanism parts Inspect the valve springs and related hardware for excessive wear or distortion Check the valves and valve seat area or inserts for evidence of deep pitting cracks or distortion Check clearance of the valve stems in the guides See Figure 10 6 for valve details and specifications Section 10 Inspection and Reconditioning EXHAUST INTAKE VALVE VALVE E hF Eo d 2 G Der Wa EXHAUST INSERT INTAKE INSERT Seat Angle Insert O D 36 987 37 013 mm 1 4562 1 4572 in 32 987 33 013 mm 1 2987 1 2997 in Guide Depth 4 mm 0 1575 in 6 5 mm
212. o the crankcase See Figure 9 35 4 Pry under the protruding edge of the breather ry x cover with a screwdriver to break the RTV or Figure 9 33 Removing Blower Housing gasket seal See Figure 9 36 Do not pry on the sealing surfaces as it could cause damage Remove Inner Baffles and Breather Cover resulting in leaks Most engines use a formed The inner valley baffles are attached at one corner gasket rather than RTV sealant using the same fasteners as the breather cover See Figure 9 34 1 Remove the two hex flange screws securing the inner baffles 9 9 Section 9 Disassembly i in E WS Cover Seal Figure 9 36 Breaking Breather 5 Remove the breather cover and gasket if used See Figure 9 37 Figure 9 37 Removing Breather Cover 6 Remove the breather filter from chamber See Figure 9 38 W Figure 9 38 Removing Breather Filter 9 10 7 Remove the hex flange screw breather reed retainer and breather reed See Figure 9 39 Figure 9 39 Removing Breather Reed Remove Valve Covers Three valve cover designs have been used The earliest type used a gasket and RTV sealant between the cover and sealing surface of the cylinder head The second type had a black O Ring installed in a groove on the underside of the cover and may have metal spacers in the bolt holes The latest design uses a brown O Ring and the bolt holes spacers are molded in place 1 Remove the four hex
213. oes not run at the expected speed The throttle linkage spring will fully open the throttle 1 Check to see that the throttle linkage and DLA plate if the linkage becomes detached from the DLA have full range of motion having no mechanical This will create an overspeed condition causing the interference engine to shut down The DLA shaft will have to be manually screwed back into the body and then 2 Testthe potentiometer wiper voltage if equipped retracted before reassembling the linkage 3 Test the SPST switch if equipped 5 13 Section 5 Fuel System and Governor 5 14 CH18 740 Section 5A LPG Fuel Systems A WARNING Explosive Fuel LPG is extremely flammable is heavier than air and tends to settle in low areas where a spark or flame could ignite the gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger the safety of persons in the area Proper service and repair of LPG fuel systems requires qualified technicians and special equipment Many states require special licensing or certification for LPG repair shops and or technicians Check state and local regulations before attempting any adjustment service or repair of the LPG system or components Faulty repairs by unqualified or underqualified personnel can have very serious ramifications The information in this segment is for the exclusive use of qualified LPG service providers LPG Fuel System
214. of 1500 m 5000 ft No internal changes are necessary or available for 2 Remove the air cleaner breather hose fuel line either carburetor vacuum hose choke and throttle linkages Remove the mounting hardware carburetor and NOTE Carburetor adjustments should be made only gaskets from the engine Discard the gaskets after the engine has warmed up 3 The carburetor venturi may be removed for Idle Speed Adjustment inspection and appropriate cleaning 1 Start the engine and run at half throttle for 5 to 10 minutes Check that the throttle and choke Nikki a Remove the four screws securing the air carburetor plates can open fully cleaner adapter and gasket to the carburetor See Figure 5A 4 2 Place the throttle control into the idle or slow position Turn the low idle speed adjusting screw See Figure 5A 2 or 5A 3 in or out to obtain a low idle speed of 1200 RPM x 75 RPM or set to application specifications Check the speed using a tachometer NOTE The actual low idle speed RPM depends on the application Refer to the equipment manufacturer s recommendations The low idle speed for basic engines is 1200 RPM LPG Fuel System Component Service LPG Carburetor Cleaning Figure 5A 4 The carburetor may be cleaned if necessary Removal from the engine and limited disassembly will aid in b Important Mark a small line on the outer cleaning edge of the venturi for proper orientation and reinstalla
215. ohol 90 unleaded gasoline by volume is approved as a fuel for Kohler engines Other gasoline alcohol blends are not approved Gasoline Ether blends Methyl Tertiary Butyl Ether MTBE and unleaded Figure 1 3 Oll Container Logo gasoline blends up to a maximum of 1596 MTBE by GE l volume are approved as a fuel for Kohler engines Other Refer to Section 6 Lubrication System for detailed gasoline ether blends are not approved procedures on checking the oil changing the oil and changing the oil filter 1 4 Periodic Maintenance Instructions A WARNING Accidental Starts Section 1 Safety and General Information Disabling engine Accidental starting can cause severe injury or death Before working on the engine or equipment disable the engine as follows 1 Disconnect the spark plug lead s 2 Disconnect negative battery cable from battery Maintenance Schedule These required maintenance procedures should be performed at the frequency stated in the table They should also be included as part of any seasonal tune up Fill fuel tank Daily or Before Check oil level Section 5 Section 6 Starting Engine Check air cleaner for dirty loose or damaged parts Section 4 Check air intake and cooling areas clean as necessary Section 4 Replace air cleaner element Section 4 Change oil More frequently under severe conditions Section 6 Remove cooling shrouds and clean cooling areas Section 4
216. om the air cleaner in the correct ratio for efficient combustion Troubleshooting Checklist If the engine starts hard runs roughly or stalls check the following areas e Make sure the LPG fuel tank is filled and shut off valve is fully opened e Make sure fuel is reaching the carburetor Make sure the air cleaner element and precleaner are clean and all components are fastened securely e Make sure the ignition governor exhaust throttle and choke control systems are all operating properly e Check compression If engine continues to start hard run roughly or stall after these checks have been made use the following troubleshooting guide Engine cranks but will not start 1 LPG fuel tank closed low or empty 2 Lock off not opening electrically preventing fuel flow to vaporizer 3 Fuelfilter located inside lock off dirty or blocked 5A 2 ALO Insufficient vacuum signal regulator not opening a Vacuum line between carburetor and regulator cracked leaking kinked or pinched b Carburetor loose c Intake manifold loose or leaking d Excessive internal engine wear Faulty regulator a Primary valve not opening b Diaphragm spring adjustment incorrect c Idle adjustment screw incorrectly set d Vent s blocked restricted Restricted blocked fuel line Blocked carburetor fuel circuit Loose leaking fuel enrichment hose Impco carburetor system Hard starting runs roughly or st
217. ombination system which allows the operator to select either gasoline or LP This section covers the standard carbureted fuel systems The gaseous systems are covered in subsection 5A and the EFI systems are covered in subsection 5B The governor systems used are covered at the end of this section A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent Fuel System Components The typical carbureted fuel system and related components include the following e Fuel Tank e Fuel Lines e In line Fuel Filter Fuel Pump e Carburetor Operation The fuel from the tank is moved through the in line filter and fuel lines by the fuel pump On engines not equipped with a fuel pump the fuel tank outlet is located above the carburetor inlet allowing gravity to feed fuel to the carburetor Fuel then enters the carburetor float bowl and is drawn into the carburetor body There the fuel is mixed with air This fuel air mixture is then burned in the engine combustion chamber Fuel Recommendations General Recommendations Purchase gasoline in small qu
218. on by decreasing engine downtime Kohler special tools are handled by SPX Corp a division of Owatonna Tool Corp OTC The tools are easy to purchase by contacting SPX OTC by phone fax or mail Phone 1 800 533 0492 Fax 1 800 578 7375 Mail SPX Corp OTC International 1 507 455 7223 1 586 578 7375 28635 Mound Rd 8 00 am 8 00 pm EST International 1 507 455 7063 Warren MI 48092 3499 Some special tools for this engine are Camsiatt Giele EU Pale Du oot a ad cant maa cased KO1031 Flywheel Strap Wrench nomion iaria a a a ei erai Na da NU10357 Flywheel Puller R EE NUS3226 Rocker Arm Spanner Weenche OEM6200 Valve Ee E E KO1026 Walter MANOMGICE EN KO1048 Cylinder L akdown Teste zoe n e uet ibus catu uo portal Sus eate e etia KO3219 Onton SYSTEM A EE Tr KO1046 Hydraulic Lifter Removal Reinstallation Tool KO1044 Starter Service Kit unana a nennen nennen nnns nn nnns nain nns KO3226 Starter Metaining RING TOO PCR 25 761 18 S Vacuum Gauge NERO EON ET cR KO3223 Tachometer Digital Inductive ccccccsseeccceseceeceeeeecsesseeeeeaeeeseaseeseaeeeesaaeeensaaes KO3216 Spark Advance Module SAM Tester ccccsscccceceeseeceeeeeeeeceeseeeeeeeseeeeeeeeeesaaeeeees KO3222 Rectifier Requlator Teste EE KO3221 Electronic Fuel Injection EFI Service Tools be dt c e E ates KO3217 EE EE KO3217 4 EE KO3217 5 E e emm KO3217 6 Jumper Plug Red for metal cased ECU nssnsnsnnsnnnssssrrnnnsrrrrenrrnrresrrrreesrrrrren KO3217 7 T
219. on should always be a thorough scrubbing with a brush and hot soapy water Use a strong detergent that is capable of breaking down the machining oil while maintaining a good level of suds If the suds break down during cleaning discard the dirty water and start again with more hot water and detergent Following the scrubbing rinse the cylinder with very hot clear water dry it completely and apply a light coating of engine oil to prevent rusting Measuring Piston to Bore Clearance Before installing the piston into the cylinder bore it is necessary that the clearance be accurately checked This step is often overlooked and if the clearances are not within specifications engine failure will usually result NOTE Do not use a feeler gauge to measure piston to bore clearance it will yield inaccurate measurements Always use a micrometer Use the following procedure to accurately measure the piston to bore clearance 1 Use a micrometer and measure the diameter of the piston 6 mm 0 24 in above the bottom of the piston skirt and perpendicular to the piston pin See Figure 10 4 Measure 6 mm above the Bottom of Piston Skirt at Right Angles to Piston Pin Figure 10 4 Measuring Piston Diameter 2 Usean inside micrometer telescoping gauge or bore gauge and measure the cylinder bore Take the measurement approximately 63 5 mm 2 5 in below the top of the bore and perpendicular to the piston pin 10 4 3 Piston t
220. ons on that side If wiring is okay replace ignition module and retest for spark b Ifthe tester shows spark but the engine misses or won t run on that cylinder try a new spark plug 8 7 Section 8 Electrical System and Components c If neither side is firing recheck position of ignition switch and check for shorted kill lead Test Procedure for SMART SPARK Ignition Systems The following procedures are provided for troubleshooting ignition problems on SMART SPARK equipped engines They will allow you to isolate and pinpoint the failed component s Special Tools Required e Hand Tachometer e Tester SPX Part No KO1046 formerly Kohler Part No 24 455 02 S e Automotive timing light e Multi meter digital Specifications Required e Spark plug gap 0 76 mm 0 030 in e Ignition module air gap 0 28 0 33 mm 0 011 0 013 in 0 30 mm 0 012 in nominal NOTE Ignition tester SPX Part No KO1046 formerly Kohler Part No 24 455 02 S must be used to test ignition on these engines Use of any other tester can result in inaccurate findings Battery on unit must be fully charged and properly connected before making any of these tests a battery that is hooked up or charged backward will crank the engine but it won t have spark Be sure drive is in neutral and all external loads are disconnected Test 1 Isolate and verify the trouble is within the engine ignition system 1 Locate the plug connectors where t
221. onto the thrust bearing Wipe some grease on the face of the original shim spacer and stick it onto the thrust washer Install the closure plate onto the crankcase without applying RTV sealant and secure it with only two or three of the fasteners at this time Use a dial indicator to check the crankshaft end play End play should be 0 05 0 50 mm 0 0020 0 0197 in except for CH25 engines below Serial No 2403500008 end play should be 0 050 0 75 mm 0 0020 0 0295 in Shim spacers are available in the three color coded thicknesses listed below if adjustment is needed Crankshaft End Play Shims GREEN 0 8366 0 9127 mm 0 8750 mm 0 034 in Nominal YELLOW 1 0652 1 1414 mm 1 1033 mm 0 043 in Nominal RED 1 2938 1 3700 mm 1 3319 mm 0 052 in Nominal 11 6 Remove the closure plate If end play requires adjustment remove the original spacer and install the appropriate size shim spacer in its place Then follow the procedure under Install Closure Plate Assembly Install Closure Plate Oil Seal 1 Check to make sure that there are no nicks or burrs in the crankshaft bore of the closure plate 2 Apply a light coat of engine oil to the outside diameter of the oil seal 3 Drive the oil seal into the closure plate using a seal driver Make sure the oil seal is installed straight and true in the bore to the depth shown in Figure 11 18 Oil Seal 314 in Figure 11 18 Oil Seal Depth in Closure Plate Insta
222. op pressure the valve opens relieving the excess pressure returning the excess fuel back to the tank Section 5B EFI Fuel System Pressure Regulating Pressure Regulating Chamber Diaphragm KH Valve Seat US Fuel Chamber Outlet Port to fuel rail Return Port to tank Figure 5B 29 Fuel Pressure Regulator Details Service Depending on the application the regulator may be located in the fuel tank along with the fuel pump or outside the tank just down line from the pump The regulator is a sealed non serviceable assembly If it is faulty it must be separated from the base holder assembly and replaced as follows Figure 5B 30 External Regulators and Base Holders 1 Shut engine off make sure engine is cool and disconnect the negative battery cable Depressurize fuel system through test valve in fuel rail see fuel warning on page 5B 2 Access the regulator assembly as required and clean any dirt or foreign material away from the area External Regulator Based upon the style of regulator used See Figure 5B 30 a Remove the two screws securing the mounting bracket to the regulator housing Remove the O Ring and pull the regulator out of the housing b Remove the snap ring and remove regulator from base holder Internal In Tank Regulator Remove the three screws securing the retaining ring and regulator in the base holder assembly Grasp and pull the regulator out of the base
223. orm Steps 10 13 in the Starter Reassembly sequence Installation must be done after the armature drive lever and frame are installed if the starter has been disassembled Section 8 Electrical System and Components Starter Service Clean the drive lever and armature shaft Apply Kohler electric starter drive lubricant Part No 52 357 02 S Versilube G322L or Mobil Temp SHC 32 to the lever and shaft Clean and check the other starter parts for wear or damage as required Starter Reassembly 1 Apply drive lubricant Kohler Part No 52 357 02 S to the armature shaft splines Install the drive pinion onto the armature shaft 2 Install and assemble the stop collar retainer assembly a Install the stop collar down onto the armature shaft with the counter bore recess up b Install a new retainer in the larger rear groove of the armature shaft Squeeze with a pliers to compress it in the groove c Slide the stop collar up and lock it into place so the recess surrounds the retainer in the groove If necessary rotate the pinion outward on the armature splines against the retainer to help seat the collar around the retainer Figure 8 57 Installing Stop Collar and Retainer NOTE Always use a new retainer Do not reuse old retainers which have been removed 3 Install the offset thrust stop washer so the smaller offset of the washer faces the retainer collar See Figure 8 58 8 33 Section
224. ostic check of itself each of the sensors and the system performance If a fault is detected the ECU turns on the Malfunction Indicator Light MIL on the equipment control panel stores the fault code in its fault memory and goes into a default operating mode Depending on the significance or severity of the fault normal operation may continue or limp home operation slowed speed richer running may be initiated A technician can access the stored fault code using a blink code diagnosis flashed out through the MIL An optional computer software diagnostic program is also available order Kohler Part No 25 761 23 S The ECU requires a minimum of 7 0 volts to operate The adaptive memory in the ECU is operational the moment the battery cables are connected however the adapted values are lost if the battery becomes disconnected for any reason The ECU will relearn the adapted values if the engine is operated for 10 15 minutes at varying speeds and loads after the oil temperature exceeds 55 C 130 F Section 5B EFI Fuel System To prevent engine over speed and possible failure a rev limiting feature is programmed into the ECU If the maximum RPM limit 4125 RPM on MA 1 7 4500 RPM on MSE 1 0 amp MSE 1 1 is exceeded the ECU suppresses the injection signals cutting off the fuel flow This process repeats itself in rapid Succession limiting operation to the preset maximum Service Never attempt to disassemble
225. ousing screws to 6 2 N m 55 in Ib in a new hole or to 4 0 N m 35 in Ib in a used hole Torque the shorter M5 side baffle screws to 4 0 N m 35 in Ib See Figure 11 64 Torque the upper M5 side baffle screws into cylinder head to 6 2 N m 55 in Ib in a new hole or to 4 0 N m x LKE 35 in Ib in a used hole Torque the two rear M6 d oa EE baffle mounting screws to 10 7 N m 95 in Ib in b eel a new hole or to 7 3 N m 65 in Ib in a used hole See Figure 11 65 Figure 11 66 Installing Metal Type Grass Screen 7 Torque the four breather cover screws to 7 3 N m 65 in Ib in the sequence shown in Figure 11 67 11 18 Section 11 Reassembly Figure 11 67 Breather Cover Fastener Torque Sequence Reconnect Rectifier Regulator 1 Install the rectifier regulator in the blower housing if removed previously then connect the rectifier regulator ground lead with the washer and silver screw through the eyelet as shown in Figure 11 68 If a grounding bracket is used secure with the lower mounting screw and washer against the outer side of the rectifier regulator See Figure 11 70 Grounding Bracket Figure 11 70 Grounding Bracket and Attached Connector SMART SPARK Module 1 On engines with SMART SPARK reinstall the SAM module to the blower housing or cylinder baffle Do not over tighten the retaining screws See Figure 11 71 z Figure 11 68 Connecting Ground Lead 2 Install the B
226. ows 1 Remove the oil temperature sensor from the adapter housing and cap or block the adapter hole 2 Wipe sensor clean and allow it to reach room temperature 20 C 68 F 3 Unplug the main harness connector from the ECU 4 With the sensor connected check the oil temperature sensor circuit resistance The value should be 2375 2625 Q See chart on pages 5B 28 5B 31 or 5B 32 35 Pin MA 1 7 Metal Cased ECU Check between the 14 and 27 pin terminals Section 5B EFI Fuel System 24 Pin MSE 1 0 Plastic Cased ECU Check The tip of the sensor protruding into the exhaust gas between the 6 and 4 pin terminals is hollow see cutaway Figure 5B 12 The outer portion of the tip is Surrounded by the exhaust gas 32 Pin MSE 1 1 Plastic Cased ECU Check with the inner portion exposed to the ambient air between the 6 and 4 pin terminals When the oxygen concentration on one side of the tip is different than that of the other side a voltage signal 5 Unplug the sensor connector and check sensor typically cycling between 0 2 and 1 0 volt is generated resistance separately Resistance value should between the electrodes and sent to the ECU The again be 2375 2625 Q voltage signal tells the ECU if the engine is straying from the ideal 14 7 1 fuel mixture and the ECU then a If the resistance is out of specifications adjusts the injector pulse accordingly replace the temperature sensor b If it is within
227. palk PIU coerente ee ee ege ee 5B 18 Lad giae deii i i e T 5B 18 5B 19 Baltery Charging sy Stein astesosesta Mandos ee pud a cate dde dec Ane mde NIE EOM NULL A LIRE S UE DUE 5B 19 Fuel Components PUGH uUo 5B 19 5B 20 F l Pressure Regulator EE 5B 20 5B 22 Si oae M EE 5B 22 SIE EE 5B 22 mE 5B 22 5B 23 Throttle Body Intake Manifold Assembly ccccceeccecseseeccaeeeeeeeeeeecsaeeeeseeeeeseaeeessauseesaeeeeessaeeesaanseees 5B 23 Idle Speed Adjustment REM EE 5B 23 5B 24 Initial Governor AdJUSHUTIGEIL cocoa eee sao tee detis eae eyes ix tod eter Rio an a aaiae idrain 5B 24 5B 26 Troubleshooting relie sebtle fetee te er 5B 26 Electrical SY SUSI EEN 5B 27 5B 33 PUCIOV SION e c 5B 34 uideo D ee 5B 34 5B 42 TFOUDIESHOOUNG FOW CIN c EM 5B 42 5B 43 Flow Chart Diagnostic Le 5B 44 5B 45 ziaker iae Mforo C rS Refer to Section 2 5B 1 Section 5B EFI Fuel System Description amp WARNING Explosive Fuel can cause fires and severe burns Fuel system ALWAYS remains under HIGH PRESSURE A WARNING Explosive Fuel Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not sta
228. pecial pantented nickel silicone plating process for increased power superior oil control reduced exhaust emission and virtually permanent cylinder life POWER BORE cylinders cannot be resized or honed as described in the following procedure If a plated cylinder bore is damaged or out of specification use a new miniblock or short block to repair the engine Use the following procedure for crankcases with a cast iron sleeve Honing While most commercially available cylinder hones can be used with either portable drills or drill presses the use of a low speed drill press is preferred as it facilitates more accurate alignment of the bore in relation to the crankshaft crossbore Honing is best accomplished at a drill soeed of about 250 RPM and 60 strokes per minute After installing coarse stones in hone proceed as follows 1 Lower hone into bore and after centering adjust so the stones are in contact with the cylinder wall Use of a commercial cutting cooling agent is recommended 2 With the lower edge of each stone positioned even with the lowest edge of the bore start drill and honing process Move the hone up and down while resizing to prevent the formation of cutting ridges Check the size frequently Section 10 Inspection and Reconditioning NOTE Kohler pistons are custom machined to exacting tolerances When oversizing a cylinder it should be machined exactly 0 25 mm 0 010 in or 0 50 mm 0 020 in over the n
229. pect the float for cracks holes and missing or damaged float tabs Check the float hinge and shaft for wear or damage e Inspect the fuel inlet needle and seat for wear or damage Inspect the tip of the low idle fuel adjusting needle for wear or grooves The choke plate is spring loaded Check to make sure it moves freely on the shaft NOTE The choke and throttle plate assemblies are staked and matched to the shafts at the factory They are not serviceable items Always use new gaskets when servicing or reinstalling carburetors Repair kits are available which include new gaskets and other components These kits are described on the next page Section 5 Fuel System and Governor Carburetor Upper Body Choke Self relieving Choke Body Gasket Formed Rubber Slow Speed Jet Inlet Needle Valve Clip Float Pin Float Assembly Kit Carburetor Lower Body Throttle Main Jet Idle Fuel Adjusting Needle some models Solenoid Seat Fuel Shut off Solenoid Kit Idle Speed Adjusting Screw Jet Accelerator Pump Carburetor only Accelerator Pump Cover Diaphragm Diaphragm Spring O Ring Rubber Boot Bushing Return Spring OO Dh eS esch b sesch h zech sesch wesch lk NOORWNM O h 3 3 N O o o 13 ee Accelerator Pump Version Only Figure 5 8 Carburetor Exploded View Components such as the throttle and choke shaft Carburetor Repair Kit assemblie
230. pen the throttle plate wider This allows more fuel into the engine increasing the engine speed As the speed reaches the governed setting the governor spring tension and the force applied by the regulating pin will again offset each other to hold a steady engine speed Adjustments NOTE Do not tamper with the governor setting Overspeed is hazardous and could cause personal injury 5 10 General The governed speed setting is determined by the position of the throttle control It can be variable or constant depending on the engine application Initial Adjustment NOTE EFlengines require a special initial adjustment procedure which is covered in subsection 5B Refer to Initial Governor Adjustment in that section for setting the governor on EFl equipped engines Procedure Carburetor Equipped Engines Make this adjustment whenever the governor arm is loosened or removed from the cross shaft See Figure 5 9 and adjust as follows 1 Make sure the throttle linkage is connected to the governor arm and the throttle lever on the carburetor 2 Loosen the hex nut holding the governor lever to the cross shaft 3 Move the governor lever toward the carburetor as far as it will move wide open throttle and hold in this position 4 Insert a nail into the hole on the cross shaft and rotate the shaft counterclockwise as far as it will turn then tighten hex nut securely Sensitivity Adjustment Governor sensitivity
231. perating pressure of 39 psi 3 If an engine starts hard or turns over but will not start it may indicate a problem with the EFI fuel system A quick test will verify if the system is operating 1 Disconnect and ground the spark plug leads 2 Complete all safety interlock requirements and crank the engine for approximately 3 seconds 3 Remove the spark plugs and check for fuel at the tips a If there is fuel at the tips of the spark plugs the fuel pump and injectors are operating b If there is no fuel at the tips of the spark plugs check the following 1 Make sure the fuel tank contains clean fresh proper fuel 2 Make sure that vent in fuel tank is open 3 Make sure fuel tank valve if so equipped is fully opened 4 Make sure battery is supplying proper voltage 5 Check that the fuses are good and that all electrical and fuel line connections are good 6 Test fuel pump and relay operation as described earlier under Fuel Pump Service 5B 34 Fault Codes The ECU continuously monitors engine operation against preset performance limits If the operation is outside the limits the ECU activates the MIL and stores a diagnostic code in its fault memory If the component or system returns to proper function the ECU will eventually self clear the fault code and turn off the MIL If the MIL stays illuminated it warns the customer that dealer service is required Upon receipt the dealer te
232. peration of fuel pump lf fuel does flow from the line check for faulty a Remove the fuel line from the inlet fitting of carburetor Refer to the Carburetor portions of carburetor this section b Crankthe engine several times and observe flow If fuel does not flow from the line check for a clogged fuel line If the fuel line is unobstructed check for overfilled crankcase and or oil in pulse line If none of the checks reveal the cause of the problem replace the pump 5 2 Fuel Pump General These engines are equipped with either a pulse or mechanical fuel pump See Figures 5 1 and 5 2 The pumping action is created by either the oscillation of positive and negative pressures within the crankcase through a hose or by direct lever pump actuation off rocker arm movement The pumping action causes the diaphragm on the inside of the pump to pull fuel in on its downward stroke and to push it into the carburetor on its upward stroke Internal check valves prevent fuel from going backward through the pump Outlet Line to Carburetor m bw Pulse Fuel 4 Pur Pump TW ix d IN i Inlet Line Figure 5 1 Pulse Style Fuel Pump Performance Minimum fuel delivery rate must be 7 5 L hr 2 gal hr with a pressure at 0 3 psi and a fuel lift of 18 in from carburetor inlet A 1 3 L hr 0 34 gal hr fuel rate must be maintained at 5 Hz Fuel Pump Replacement Replacing the Pulse Fuel Pump Replacement pu
233. permanent system damage may occur 2 Crankthe engine over establishing a minimum of 550 600 RPM and observe tester s for spark 3 Onatwin cylinder engine repeat the spark test on the opposite cylinder if cylinders are being tested individually a If both cylinders have good spark but the engine runs poorly install new spark plugs gapped at 0 76 mm 0 030 in and retest engine performance If problem persists go to Test 3 b If one cylinder had good spark but the other cylinder had no spark or intermittent spark go to Test 3 c lf there was no spark or intermittent spark on both cylinders go to Test 4 Test 3 Check for timing advance Figure 8 8 1 Make a line near the edge of the flywheel screen with a marking pen or narrow tape 2 Connect an automotive timing light to cylinder that had good spark Figure 8 9 3 Runthe engine at idle and use the timing light beam to locate the line on the screen Draw a line on the blower housing adjacent to the line on the screen Accelerate to full throttle and watch for movement of the line on the screen relative to the line on the blower housing If both cylinders had good spark repeat the test on the other cylinder a If the line on the screen moved away from the line on the blower housing during acceleration the SAM is working properly If it didnt move away go to Test 5 Section 8 Electrical System and Components b If you were able to ch
234. phragm 12 is drawn down and contacts the secondary lever 16 Fuel will flow in proportion to air velocity through the carburetor venturi ensuring an ideal mixture at all engine speeds GALLS ESS PUBL 22 lg zona n Ge Dee 4 SS TA E SN N Eeer N TO 7 AC LITT A ZZ Ze sm LLL d ZA S S LN N of 22 Secondary Diaphragm Pan Head Screw 1 8 27 NPT Plug Primary Diaphragm Assembly Expansion Plug Secondary Pivot Pin Whenever the engine is operating the vacuum diaphragm 10 is down against the floor H and the spring 11 is compressed The idle and starting adjustment is made with a tamper resistant screw 17 which regulates the whisker wire system not shown opening up the secondary orifice slightly but only when the vacuum diaphragm is drawn down Very little vacuum is needed to start this vacuum diaphragm travel 0 2 Mercury to start and 0 5 Mercury for full travel The instant the engine stops rotating loss of vacuum in section D releases diaphragm 10 causing bumper K to push against secondary lever 16 overcoming action of whisker wire and ensuring 100 lock off This patented Beam design will lock off primary pressures up to five times in excess of normal and permits starting without priming or choking 5A 10 12 13 Primary Spring 14 Secondary Lever Spring 15 16 Secondary Diaphragm Spring Primary Lever Assembly Fillister Head Screw Primary Pivot Pin
235. point for the speed at which the engine is running At the proper instant it releases the flow of primary current to the coil The primary current induces high voltage in the coil secondary which is then delivered to the spark plug Each coil fires every revolution but every other spark is wasted Service Except for removing the spark plug lead by unscrewing it from the secondary tower see Figure 5B 22 no coil servicing is possible If a coil is determined to be faulty replacement is necessary An ohmmeter may be used to test the wiring and coil windings Figure 5B 22 Ignition Coil NOTE Do not ground the coils with the ignition on as they may overheat or spark Testing 1 Disconnect the main harness connector from ECU 35 Pin MA 1 7 Metal Cased ECU Locate pins 1 and 19 in the 35 pin connector See page 5B 28 5B 17 Section 5B EFI Fuel System 24 Pin MSE 1 0 Plastic Cased ECU Locate pins 22 and 23 in the 24 pin connector See page 5B 31 32 Pin MSE 1 1 Plastic Cased ECU Locate pins 30 and 31 in the 32 pin connector See page 5B 32 Disconnect connector from relay and locate terminal 487 in connector Using an ohmmeter set on the Rx1 scale check the resistance in circuits as follows 35 Pin MA 1 7 Metal Cased ECU Check between terminal 87 and pin 1 for coil 1 Repeat the test between terminal 87 and pin 19 for coil 2 24 Pin MSE 1 0 Plastic
236. ponent subassembly work has been completed The sequence may vary to accommodate options or special equipment Detailed procedures follow 1 Install flywheel end oil seal 2 Install governor cross shaft 3 Install crankshaft 4 Install connecting rods with pistons and rings 5 Install camshaft 6 Install closure plate assembly 7 Install stator and backing plates 8 Install flywheel 9 Install fan and grass screen 10 Install hydraulic lifters 11 Install cylinder heads 12 Install ignition modules 13 Install intake manifold 14 Install breather cover and inner baffles 15 Install blower housing and outer baffles 16 Install electric starter motor 17 18 19 20 21 22 23 24 20 26 2f Install fuel pump Install carburetor Install external governor controls Install throttle and choke controls Install Oil Sentry Install control panel if so equipped Install valve covers Install air cleaner assembly see Section 4 Install muffler Install oil filter and add oil to crankcase Connect spark plug leads Install Fl ywheel End Oil Seal 1 2 Make sure that the seal bore of the crankcase is clean and free of any nicks or burrs See Figure 11 1 Apply a light coat of clean engine oil to the outside diameter of the oil seal Drive the oil seal into the crankcase using a seal driver Make sure the oil seal is installed straight and true in the bore and that the tool bottoms
237. pplied with the tester can be used if the PTO end of the crankshaft is accessible Lock the holding tool 3 4 Disassemble breather clean parts thoroughly check sealing surfaces for flatness reassemble and recheck pressure Replace all worn or damaged seals and gaskets Make sure all fasteners are tightened securely Use appropriate torque values and sequences when necessary Recondition piston rings cylinder bore valves and valve guides Repair replace restricted muffler exhaust system onto the crankshaft Install a 3 8 breaker bar into the hole slot of the holding tool so it is perpendicular to both the holding tool and crankshaft PTO If the flywheel end is more accessible use a breaker bar and socket on the flywheel nut screw to hold it in position An assistant may be needed to hold the breaker bar during testing If the engine is mounted in a piece of equipment it may be possible to hold it by clamping or wedging a driven component Just be certain that the engine cannot rotate off of TDC in either direction Install the adapter into the spark plug hole but do not attach it to the tester at this time Connect an air source of at least 50 psi to the tester Turn the regulator knob in the increase clockwise direction until the gauge needle is in the yellow set area at the low end of the scale Connectthe tester quick disconnect to the adapter hose while firmly holding the engine at TDC Note
238. prescribed parameters If the voltage readings show a steady decline bump the governor lever to make the engine accelerate very quickly and check the reading again If voltage momentarily increases and then again declines without cycling engine may be running lean due to incorrect TPS initialization Shut off the engine perform TPS initialization and then repeat the test If TPS initialization cannot be achieved perform step c c Replace the oxygen sensor page 5B 13 Run the engine long enough to bring the new sensor up to temperature and repeat the output test from step 1 The cycling voltage from 0 2 to 1 0 volt should be indicated 2 Move the black voltmeter lead to the engine ground location and repeat the output test The same voltage 0 2 v 1 0 v should be indicated a If the same voltage reading exists go on to Step 3 b If the voltage output is no longer correct a bad ground path exists between the sensor and the engine ground Touch the black lead at various points backtracking from the engine ground back toward the sensor watching for a voltage change at each location If the correct voltage reading reappears at some point check for a problem rust corrosion loose joint or 5B 12 connection between that point and the previous checkpoint For example if the reading is too low at points on the crankcase but correct voltage is indicated when the black lead is touched to the skin of the muffler the f
239. problem 5 Ignition System Related a Non resistor spark plug s used Code 22 Source Throttle Position Sensor TPS Explanation Unrecognizable signal is being sent from sensor too high too low inconsistent Expected Engine Respon se A limp home operating mode occurs with an overall decrease in operating performance and efficiency Fuel delivery is based upon the oxygen sensor and five mapped values only Rich running black smoke will occur until closed loop operation is initiated A stumble or misfire on hard acceleration and or erratic operation may be exhibited Possible Causes 1 TPS Sensor Related a b C 2 hr a Sensor connector or wiring Sensor output affected or disrupted by dirt grease oil wear or breather tube position must be to side opposite the TPS Sensor loose on throttle body manifold ottle Body Related Throttle shaft or bearings worn damaged 3 Engine Wiring Harness Related 35 Pin MA 1 7 Metal Cased ECU a b Pin circuits 12 25 and or 27 damaged wiring or connectors Pin circuits 12 25 and or 27 routed near noisy electrical signal coils alternator Intermittent 5 volt source from ECU pin circuit 25 3 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a b Pin circuits 4 8 and or 14 damaged wiring connectors Pin circuits 4 8 and or 14 routed near noisy electrical signal coils alternator
240. r being used A typical cutter is shown in Figure 10 7 The final cut should be made with an 89 cutter as specified for the valve seat angle in Figure 10 6 Cutting the proper 45 valve face angle as specified in Figure 10 6 and the proper valve seat angle 44 5 half of the full 89 angle will achieve the desired 0 5 1 0 full cut interference angle where the maximum pressure occurs on the outside diameters of the valve face and seat 10 8 Figure 10 7 Typical Valve Seat Cutter Lapping Valves Reground or new valves must be lapped in to provide proper fit Use a hand valve grinder with a suction cup for final lapping Lightly coat the valve face with a fine grade of grinding compound then rotate the valve on its seat with the grinder Continue grinding until a smooth surface is obtained on the seat and on the valve face Thoroughly clean the cylinder head in soap and hot water to remove all traces of grinding compound After drying the cylinder head apply a light coating of SAE 10 oil to prevent rusting Intake Valve Stem Seal These engines use valve stem seals on the intake valves Always use a new seal when the valves are removed from the cylinder head The seals should also be replaced if deteriorated or damaged in any way Never reuse an old seal Pistons and Rings Inspection Scuffing and scoring of pistons and cylinder walls occurs when internal engine temperatures approach the welding point of the piston
241. retor as far as it will go wide open throttle and hold in position See Figure 11 78 Figure 11 78 Adjusting Governor Lever 4 Insert a nail into the hole on the cross shaft and rotate the shaft counterclockwise as far as it will turn then torque the hex nut to 6 8 N m 60 in Ib See Figure 11 79 Figure 11 79 Holding and Tightening Governor Arm 5 Reconnect the lead wire to the fuel shut off solenoid if so equipped Install Throttle amp Choke Controls 1 Connect the choke linkage to the carburetor and choke actuator lever See Figure 11 80 11 22 TON a T Figure 11 80 Connecting Choke Linkage 2 Mount the main control bracket and air cleaner support bracket if used to the cylinder heads using the four hex flange screws Torque the screws to 10 7 N m 95 in Ib into new holes or 7 3 N m 65 in Ib into used holes See Figure 11 81 S i PIA e d x Figure 11 81 Torquing Main Control Bracket Section 11 Reassembly 3 Connect the governor spring from the main control bracket to the appropriate hole in the governor lever as indicated in the following charts Note that hole positions are counted from the pivot point of the governor lever See Figure 11 82 and the appropriate chart Figure 11 82 Connecting Spring to Governor Lever 6 mm Governor Lever and Hole Position RPM Chart Gov Lever Governor Spring High Idle RPM Hole No Color Code 3801 4000
242. retor as far as it will go 7 Check that the throttle plate is now fully open or reposition the carburetor slightly on the mounting screws so it is fully open Torque the mounting screws to 9 9 N m 88 in Ib Instructions for Checking Positioning the Clamp Brackets Mounted on the Throttle Shaft Use only if the position or mounting of the clamp bracket s has been disturbed Figures show the carburetor removed from the engine for clarity 5A 6 Idle Speed Clamp Bracket Position Counting the number of turns back the idle speed adjustment screw off counterclockwise so only 1 to 1 1 2 of the threads are visible See Figure 5A 8 1 2 3 e gl j E Figure 5A 8 Backing Off Idle Speed Screw Figure 5A 9 Closing Throttle Plate Idle Speed Clamp Bracket Mounting Screw Loosen the clamp bracket mounting screw and pivot the throttle shaft to fully close the throttle plate See Figure 5A 9 Hold the throttle plate closed and rotate the clamp bracket until the end of the screw contacts the stop Insert a 0 025 mm 0 001 in feeler gauge between the carburetor housing and the side of the clamp bracket to set the endplay then tighten the mounting screw securely See Figure 5A 10 Section 5A LPG Fuel Systems 3 Insert a 0 025 mm 0 001 in feeler gauge between the side of the stop collar and the carburetor housing then check or set the position of the stop collar The head of the mounting screw m
243. rnal servicing possible If a problem with the relief valve is encountered the oil pump should be replaced Relief Valve EEUU ri ni Figure 10 15 Oil Pump Oil Pickup and Relief Valve Original Style Relief Valve Figure 10 16 Oil Pump Oil Pickup and One Piece Relief Valve Later Style Inspection Inspect the oil pump housing gear and rotors for nicks burrs wear or any visible damage If any parts are worn or damaged replace the oil pump Inspect the oil pressure relief valve piston It should be free of nicks or burrs Check the spring for wear or distortion The free length of the spring should be approximately 47 4 mm 1 8 in Replace the spring if it is distorted or worn See Figure 10 17 Spring L Roll Pin Figure 10 17 Oil Pressure Relief Valve Piston and Spring Reassembly 1 Install the pressure relief valve piston and spring 2 Install the oil pickup to the oil pump body Lubricate the O Ring with oil and make sure it remains in the groove as the pickup is being installed Section 10 Inspection and Reconditioning 3 Install the rotor 4 Install the oil pump body to the closure plate and secure with the two hex flange screws Torque the hex flange screws as follows First Time Installation 10 7 N m 95 in Ib All Reinstallations 6 7 N m 60 in Ib 5 After torquing rotate the gear and check for freedom of movement Make sure there is no binding If
244. rolled injection of the fuel occurs each crankshaft revolution or twice for each 4 stroke cycle One half the total amount of fuel needed for one firing of a cylinder is injected during each injection When the intake valve opens the fuel air mixture is drawn into the combustion chamber ignited and burned Section 5B EFI Fuel System The ECU controls the amount of fuel injected and the ignition timing by monitoring the primary sensor signals for engine temperature speed RPM and throttle position load These primary signals are compared to preprogrammed maps in the ECU computer chip and the ECU adjusts the fuel delivery to match the mapped values An oxygen sensor provides continual feedback to the ECU based upon the amount of unused oxygen in the exhaust indicating whether the fuel mixture being delivered is rich or lean Based upon this feedback the ECU further adjusts fuel input to reestablish the ideal air fuel ratio This operating mode is referred to as closed loop operation The EFI system operates closed loop when all three of the following conditions are met a The oil temperature is greater than 35 C 95 F E3 b The oxygen sensor has warmed sufficiently to provide a signal minimum 375 C 709 F c Engine operation is at a steady state not starting warming up accelerating etc During closed loop operation the ECU has the ability to readjust temporary and learned adaptive controls provid
245. rt the engine near spilled fuel Never use gasoline as a cleaning agent The EFI fuel system remains under high pressure even when the engine is stopped Before attempting to service any part of the fuel system the pressure must be relieved Pressure tester SPX Part No KO3217 4 has an integral relief valve Connect the black tester hose to the test valve in the fuel rail Route the clear hose into a portable gasoline container Depress the button on the tester relief valve Initial Starting Priming Procedure Important The EFI fuel system must be purged of all air prior to the initial start up and or any time the system has been disassembled On most engines that can be done similar to relieving fuel pressure as described above Test Valve in Fuel Rail 1 Connect the pressure gauge as described above for relieving fuel pressure Depress and hold the release button and crank the engine in 10 15 second intervals allowing a 60 second cool down period between intervals until air is purged and fuel is visible in discharge tube 2 f you do not have the pressure gauge follow the procedure for engines without a test valve 5B 2 NO Test Valve in Fuel Rail 1 Crank the engine in 10 15 second intervals allowing a 60 second cool down period between cranking intervals until the engine starts NOTE The number of cranking intervals necessary will depend on the individual system design and or where the system has been disassem
246. rubber band from the throttle lever 10 Disconnect negative battery cable temporarily E3 to clear all learned adjustments Figure 5B 8 Service Connector Plug Metal Cased 11 Reconnect the battery cable and all external ECU Harness loads Readjust the idle speed to the equipment manufacturer s specified setting and recheck the high speed no load RPM setting Observe the overall performance TPS Initialization Procedure For 32 Pin MSE 1 1 Plastic Cased ECU Only Auto Learn Initialization 1 Check that the basic engine all sensors fuel fuel pressure and battery are good and functionally within specifications Important 2 Remove disconnect ALL external loads from the engine belts pumps electric PTO clutch Figure 5B 9 Service Connector Plug Plastic alternator rectifier regulator etc Cased ECU Harness 3 Locate the service connector plug in the wiring 8 Hold throttle against idle speed stop screw turn harness To initiate the TPS auto learn function the ignition switch to on position do not start connect a jumper wire from the TPS initialization engine and observe the Malfunction Indicator pin 24 violet wire to the battery voltage pin Light MIL red wire or use jumper plug SPX Part No KO3217 9 If using the PC based diagnostic tool a The light should blink on off quickly for and software Kohler Part No 25 761 23 S go to approximately 3 seconds and then go off an
247. s If it is a Command rod you will need to grind off the aligning steps so the joint surface is flat Find a 1 in long capscrew with the correct thread size to match the threads in the connecting rod Obtain a flat washer with the correct TD to slip on the capscrew and an O D of approximately 1 in Kohler Part No 12 468 05 S can be used if you don t have the right size on hand Assemble the capscrew and washer to the joint surface of the rod as shown in Figure 2 3 Figure 2 3 Rocker Arm Crankshaft Tool Cylinder Leakdown Tester A Cylinder Leakdown Tester SPX Part No KO3219 formerly Kohler 25 761 05 S is a valuable alternate to a compression test on these engines See Figure 2 4 By pressurizing the combustion chamber from an external air source this tool can determine if valves or rings are leaking Instructions for using this tester are found in Section 3 of this manual Figure 2 4 Cylinder Leakdown Tester RTV Silicone Sealant RTV silicone sealant is used as a gasket between the crankcase and closure plate Only oxime based oil resistant RTV sealants such as those listed below are approved for use Loctite Nos 5900 and 5910 are recommended for best sealing characteristics Loctite Ultra Blue 587 Loctite Ultra Copper Loctite Ultra Black 598 Loctite 5900 Heavy Body Loctite 5910 NOTE Always use fresh sealant Using outdated sealant can result in leakage Loctite 5900 is available in a 4 oz aero
248. s isolating it from the main wiring harness and the ignition module s Testing may be performed with the module mounted or loose The figures show the part removed from the engine for clarity Figure 8 10 1 Connect the tester to the SAM as follows Attach The yellow tester lead to the long yellow module lead The brown tester lead to the long brown module lead The red tester lead to the red module lead The green tester lead to the green module lead UO OU Caution Do not allow the alligator clip leads to touch each other Figure 8 11 Section 8 Electrical System and Components Figure 8 12 2 Check the SAM part number stamped on the side of the housing and determine if you have an analog SAM ASAM or a digital SAM DSAM Follow sub step a for an ASAM and sub step b for a DSAM To help identify Service Bulletin 233 lists DSAM part numbers a ASAM only Depress the tester button and hold it down After approximately four seconds a numerical sequence should be displayed beginning with 1 or 2 and continuing to 8 or 9 followed by a letter P pass or F fail See Figures 8 11 and 8 12 DO NOT release the tester button until the test cycle completes and the display goes off If you get a sign instead of the numerical sequence and or an F at the end of the cycle the SAM is probably bad Recheck all of the connections check the condition of the tester battery and repeat
249. s loss of compression and excessive oil consumption To check valve guide to valve stem clearance thoroughly clean the valve guide and using a split ball gauge measure the inside diameter of the guide Then using an outside micrometer measure the diameter of the valve stem at several points on the stem where it moves in the valve guide Use the largest stem diameter to calculate the clearance by subtracting the stem diameter from the guide diameter If the intake clearance exceeds 0 038 0 076 mm 0 0015 0 003 in or the exhaust clearance exceeds 0 050 0 088 mm 0 0020 0 0035 in determine whether the valve stem or guide is responsible for the excessive clearance The maximum I D wear on the intake valve guide is 7 134 mm 0 2809 in while 7 159 mm 0 2819 in is the maximum allowed on the exhaust guide The guides are not removable but can be reamed 0 25 mm 0 010 in oversize with SPX Tool No KO1026 Valves with 0 25 mm oversize stems must then be used If the guides are within limits but the valve stems are worn beyond limits install new valves Valve Seat Inserts Hardened steel alloy intake and exhaust valve seat inserts are press fitted into the cylinder head The inserts are not replaceable but can be reconditioned if not too badly pitted or distorted If cracked or badly warped the cylinder head should be replaced Recondition the valve seat inserts following the instructions provided with the valve seat cutte
250. s throttle plate choke plate low idle fuel Float Kit needle and others are available separately High Altitude Kit 1525 3048 m 5 000 10 000 ft High Altitude Kit over 3048 m 10 000 ft Always refer to the Parts Manual for the engine being solenoid Assembly Kit serviced to ensure the correct repair kits and Accelerator Pump Seal and Bushing Kit replacement parts are ordered Service repair kits Accelerator Pump Diaphragm Kit available for the carburetor and affiliated components Choke Repair Kit are 5 9 Section 5 Fuel System and Governor Reassembly Reassemble the carburetor using the following steps See Figure 5 9 Governor Spring f 4 1 Assemble the fuel inlet needle to the float tab Install the float float shaft and inlet needle to the air horn Tighten the screw Check float height using the procedure found previously in the Adjustments subsection Governor Arm 2 Install the slow jet with the stepped end toward Ae Throttle the bottom of the carburetor Make sure jet is fully Linkage seated 3 Install the low idle adjusting needle and spring As the flyweights move outward they cause the 4 Assemble the upper body onto the lower regulating pin to move outward carburetor body using the four screws Torque the screws to 1 7 N m 15 in Ib The regulating pin contacts the tab on the cross shaft causing the shaft to rotate 5 Install the carburetor on the engine following the procedures
251. s are destroyed and the gear must be replaced Therefore remove the gear only if absolutely necessary 1 Remove the regulating pin and governor gear assembly See Figure 10 13 Figure 10 13 Removing Governor Gear 2 Remove the locking tab thrust washer located under the governor gear assembly 3 Carefully inspect the governor gear shaft and replace it only if it is damaged After removing the damaged shaft press or lightly tap the replacement shaft into the closure plate to the depth shown in Figure 10 14 year Shaft 34 0 mm 1 3386 in 33 5 mm 1 3189 in Figure 10 14 Governor Shaft Press Depth 10 12 Reassembly 1 Install the locking tab thrust washer on the governor gear shaft with the tab down 2 Position the regulating pin within the governor gear flyweight assembly and slide both onto the governor shaft Oil Pump Assembly Disassembly 1 Remove the two hex flange screws 2 Remove the oil pump assembly from the closure plate 3 Remove the oil pump rotor 4 Remove the oil pickup by unhooking the locking clip and pulling it free from the oil pump body 5 Ifthe relief valve is like that shown in Figure 10 15 drive out the pin to remove the oil pressure relief valve piston and spring Refer to the following inspection and reassembly procedures If the relief valve is a one piece style staked to the oil pump housing See Figure 10 16 removal should not be attempted nor is inte
252. s are numbered on the crankcase Use the numbers to mark each Remove Connecting Rods with Pistons end cap connecting rod and piston for and Rings reassembly Do not mix end caps and 1 Remove the two hex flange screws securing the connecting rods closest connecting rod end cap Remove the end cap See Figure 9 65 Figure 9 67 Removing Piston Connecting Rod Assemblies Ta Figure 9 65 Removing Connecting Rod Bolts l l 2 Carefully remove the connecting rod and piston NOTE Ifa carbon ridge is present at the top of assembly from the cylinder bore See Figure 9 67 either cylinder bore use a ridge reamer tool to remove the ridge before 3 Repeat the above procedures for the other attempting to remove the piston connecting rod and piston assembly 9 17 Section 9 Disassembly Remove Crankshaft 1 Carefully pull the crankshaft from the crankcase See Figure 9 68 Note thrust washers and shims If used oving Crankshaft Figure 9 68 Rem Remove Governor Cross Shaft 1 Remove the hitch pin and plain washer or the retainer and nylon washer from the governor cross shaft See Figures 9 69 and 9 70 7 i 4 E h D td ilf n Wu mm i K l i ad LM 3 S i Ki W Figure 9 69 Removing Governor Cross Shaft Hitch Pin 6 mm Shaft Design 9 18 Figure 9 70 Removing Governor Cross Shaft Retainer 8 mm Shaft Design 2 Pull the cross shaft with small washer out through the inside of the crankcase
253. season to minimize gum deposits in your fuel system and to ensure easy starting TEMPERATURE RANGE EXPECTED BEFORE NEXT CIL CHANGE Use of synthetic oil having 5W 20 or 5W 30 rating is acceptable up to 40 Synthetic oils will provide better starting in extreme Do not add oil to the gasoline cold below 10 F NOTE Using other than service class SG SH SJ or higher oil or extending oil change intervals longer than recommended can cause engine damage Do not overfill the fuel tank Leave room for the fuel to expand Fuel Type For best results use only clean fresh unleaded gasoline with a pump sticker octane rating of 87 or higher In countries using the Research method it should be 90 octane minimum NOTE Synthetic oils meeting the listed classifications may be used with oil changes performed at the recommended intervals However to allow piston rings to properly seat a new or rebuilt m l engine should be operated for atleast 50 hours Unleaded gasoline is recommended as it leaves less using standard petroleum based oil before combustion chamber deposits and reduces harmful switching to synthetic oil exhaust emissions Leaded gasoline is not recommended and must notbe used on EFI engines A logo or symbol on oil containers identifies the API or on other models where exhaust emissions are service class and SAE viscosity grade See Figure 1 3 regulated Gasoline Alcohol blends Gasohol up to 10 ethyl alc
254. shaft Torque the screw to 7 4 8 5 N m 65 75 in Ib 7 5 Section 7 Retractable Starter 7 6 CH18 745 Section 8 Electrical System and Components This section covers the operation service and repair of the electrical system components Systems and components covered in this section are e Spark Plugs Battery and Charging System Electronic CD Ignition System including SMART SPARK on applicable models Electric Starter Spark Plugs Engine misfire or starting problems are often caused by a spark plug that has improper gap or is in poor condition The engine is equipped with the following spark plugs Type The standard spark plug is a Champion RC12YC Kohler Part No 12 132 02 S A high performance spark plug Champion Platinum 3071 used on Pro Series engines Kohler Part No 25 132 12 S is also available Equivalent alternate brand plugs can also be used Gap 0 76 mm 0 030 in Thread Size 14mm Reach 19 1 mm 3 4 in Hex Size 15 9 mm 5 8 in Spark Plug Service Every 200 hours of operation remove each spark plug Check its condition and either reset the gap or replace with a new plug as necessary To service the plugs perform the following steps 1 Before removing each spark plug clean the area around the base of the plug to keep dirt and debris out of the engine 2 Remove the plug and check its condition See Inspection following this procedure Replace the
255. shing occurs reattach connectors to both injectors Disconnect the main harness 2 Disconnect spark plug leads from spark plugs connector from the ECU and the connector from the relay Set the ohmmeter to the Rx1 3 Remove the air cleaner outer cover inner wing scale and check the injector circuit resistance nut element cover and air cleaner element as follows precleaner Service air cleaner components as required 35 Pin MA 1 7 Metal Cased ECU Check the resistance between the relay terminal 87 4 Remove the two screws securing the air cleaner and pin 35 in main connector Resistance base to throttle body manifold Remove the air should be 4 15 Q cleaner base to permit access to the injectors Check condition of air cleaner base gasket 24 Pin MSE 1 0 Plastic Cased ECU replace if necessary Check the resistance between relay terminal 87 and pin 16 in main connector Then 5 Remove the flywheel screen if it overlaps the check resistance between relay terminal 87 blower housing and pin 17 Resistance should be 4 15 Q for each circuit 6 Ifthe engine has a radiator type oil cooler mounted to the blower housing remove the two 32 Pin MSE 1 1 Plastic Cased ECU oil cooler mounting screws Check the resistance between relay terminal 87 and pin 14 in the main connector Then 7 Remove the blower housing mounting screws check the resistance between relay terminal Note the location of the plated silver
256. sing Pawls Dogs Replacement To replace the pawls follow disassembly steps 1 4 and reassembly steps 3 8 on the following pages A pawl repair kit is available which includes the following components ay Pawl Retainer Center Screw Pawl Dog Spring Brake Spring Starter Pawl Dog Brake Washer Washer Disassembly A WARNING Spring Under Tension Do not remove the center screw from the starter until the spring tension is released Removing the center screw before releasing spring tension or improper starter disassembly can cause the sudden and potentially dangerous release of the spring Follow these instructions carefully to ensure personal safety and proper starter disassembly Make sure adequate face protection is worn by all persons in the area 1 Release the spring tension and remove the handle and the starter rope Refer to Rope Replacement steps 2 through 5 on pages 7 1 and 7 2 2 Remove the center screw washer and pawl retainer See Figure 7 4 3 Remove the brake spring and the brake washer See Figure 7 5 4 Carefully note the positions of the pawls and pawl springs before removing them Remove the pawls and pawl springs from the starter pulley enter Screw gd E m Sa m em Da am ff s H LA Wi Es Figure 7 4 Center Screw Washer and Pawl Retainer Section 7 Retractable Starter Figure 7 5 Brake Spring and Washer Pawls and Pawl Springs 5
257. sition 84 BTDC for cylinder 1 This signal serves as a reference for the control of ignition timing by the ECU Synchronization of the inductive speed pickup and crankshaft position takes place during the first two revolutions each time the engine is started The sensor must be properly connected at all times If the sensor becomes disconnected for any reason the engine will quit running Service The engine speed sensor is a sealed non serviceable assembly If Fault Code diagnosis indicates a problem within this area check and test as follows 1 Check the mounting and air gap of sensor It must be 1 5 mm x 0 25 mm 0 059 x 0 009 in 2 Inspect the wiring and connections for damage or problems 3 Make sure the engine has resistor type spark plugs 4 Disconnect main harness connector from ECU 5 Connect an ohmmeter between the designated pin terminals in the plug 35 Pin MA 1 7 Metal Cased ECU 3 and 21 pin terminals 24 Pin MSE 1 0 Plastic Cased ECU 9 and 10 pin terminals 32 Pin MSE 1 1 Plastic Cased ECU 9 and 10 pin terminals See pages 5B 28 5B 33 according to ECU style A resistance value of 750 1000 Q at room temperature 20 C 68 F should be obtained If resistance is correct check the mounting air gap toothed ring gear damage runout etc and flywheel key 5B 6 6 Disconnect the speed sensor connector from wiring harness It is the connector with one
258. so occur as a result of an inadequate ground lead connection Make certain the connection location is clean and the clamp is secure 25 Amp Rectifier Regulators Original Style 1 Connect the squared single end of the tandem lead adapter to the B center red lead of rectifier regulator being tested See Figure 8 26 Figure 8 26 2 Connect the ground lead of tester with spring clamp to the housing of rectifier regulator 3 Connect the red lead and one of the black leads from the tester to the pair of terminals on opposite end of adapter lead connections are not location specific 4 Connect the remaining black lead from tester to one of the black AC outside leads from rectifier regulator See Figure 8 27 8 18 Figure 8 27 5 Plug the tester into a 110 volt AC outlet power supply and turn on the power switch The POWER light should be illuminated and one of the four status lights may be on as well See Figure 8 22 This does not represent the condition of the part 6 Press the TEST button until a click is heard and then release See Figure 8 23 Momentarily one of the four lights will relight indicating the partial condition of the part a If the OK green light comes on disconnect the tester black lead attached to the AC lead reconnect it to the opposite side AC lead and repeat the test If the OK light green again comes on the part is good and may be used b If
259. sol dispenser with replacement tips under Kohler Part No 25 597 07 S See Figure 2 5 Figure 2 5 Loctite 5900 Aerosol Dispenser Camshaft Break in Lubricant Camshaft lubricant Kohler Part No 25 357 14 S Valspar ZZ613 should be used whenever a new camshaft and lifters are installed for proper break in upon initial startup Lubricant is included with each replacement camshaft and lifter or may also be obtained separately in a 1 8 oz handy dispensing tube by the part number listed See Figure 2 6 Section 2 Special Tools Figure 2 6 Camshaft Break in Lubricant Spline Drive Lubricant Special spline drive crankshaft lubricant Kohler Part No 25 357 12 S is available in a 2 8 oz tube for use on all spline drive applications This lubricant provides proper protection against wear related damage See Figure 2 7 Figure 2 7 Crankshaft Spline Drive Lubricant Dielectric Grease Dielectric grease is applied to the outside of the terminal connections on the SMART SPARK ignition modules to prevent formation of a moisture path and arcing between the terminals The chart below lists the approved dielectric greases Dielectric Grease Vendor No Kohler Vendor Description Part No Lubri Sel 2 3 Section 2 Special Tools 2 4 CH18 745 Section 3 Troubleshooting Troubleshooting Guide When troubles occur be sure to check the simple causes which at first may seem too obvious to be considered
260. stem Clogged fuel line Loose or faulty wires or connections Faulty or misadjusted choke or throttle controls Faulty spark plugs Low compression Weak spark Fuel pump malfunction causing lack of fuel Engine overheated cooling air circulation restricted Quality of fuel Flywheel key sheared Intake system leak Engine Will Not Crank DI Oe PTO drive is engaged Battery is discharged Safety interlock switch is engaged Loose or faulty wires or connections Faulty key switch or ignition switch Faulty electric starter or solenoid Seized internal engine components Engine Runs But Misses Oi IS OS Dirt or water in the fuel system Spark plug lead disconnected Poor quality of fuel Faulty spark plug s Loose wires or connections that intermittently ground the ignition kill circuit Engine overheated Faulty ignition module or incorrect air gap Carburetor adjusted incorrectly SMART SPARK malfunction applicable models 3 1 Section 3 Troubleshooting Engine Will Not Idle So NS OY Dirt or water in the fuel system Stale fuel and or gum in carburetor Faulty spark plugs Fuel supply inadequate Idle speed adjusting screw improperly set Idle fuel adjusting needle improperly set some models Low compression Restricted fuel tank cap vent Engine overheated cooling system air circulation problem Engine Overheats 1 nir D aod Air intake grass screen cool
261. stem TPS Sensor Related a Throttle plate position incorrectly set or registered during Initialization b TPS problem or malfunction Engine Wiring Harness Related a Difference in voltage between sensed voltage pin circuit 17 for metal cased ECU pin circuit 2 for plastic cased ECU and actual injector voltage circuit 45 45A Systems Related a Ignition spark plug plug wire ignition coil b Fuel fuel type quality injector fuel pump fuel pressure Combustion air air cleaner dirty restricted intake leak throttle bores Base engine problem rings valves Exhaust system leak Fuel in the crankcase oil g Blocked or restricted fuel return circuit to tank e oe 6 ECU Harness Related a ECU to harness connection problem Code 34 Source Explanation Oxygen Sensor Fuel System Components Long term fuel adaptation control is at the upper or lower limit Expected Engine Response System operates closed loop No appreciable performance loss as long as the temporary adaptation can provide sufficient compensation Possible Causes il Oxygen Sensor Related Sensor connector or wiring problem Sensor contaminated or damaged Exhaust leak Poor ground path Pin circuit wiring or connectors Pin 10 for 35 Pin MA 1 7 Metal Cased ECU Pin 11 for 24 Pin MSE 1 0 Plastic Cased ECU Pin 20 for 32 Pin MSE 1 1 Plastic Cased ECU D Go D Dm TPS Se
262. tall Stator and Backing Plates 1 Apply pipe sealant with Teflon Loctite No 59241 or equivalent to the stator mounting holes 2 Position the stator aligning the mounting holes so that the leads are at the bottom towards the crankcase Dr Figure 11 20 Using Spanner Wrench to Turn Crankshaft 3 Install and torque the two hex flange screws to 6 2 N m 55 in Ib See Figure 11 23 Section 11 Reassembly Figure 11 23 Torquing Stator Screws 4 Route the stator leads in the crankcase channel then install the backing plates and the stator wire bracket if used Secure using the four hex flange screws See Figures 11 24 and 11 25 Torque the screws to 7 3 N m 65 in Ib Figure 11 25 Installing Backing Plates and Stator Wire Bracket 11 8 Install Flywheel WARNING Damaging Crankshaft and Flywheel Can Cause Personal Injury Using improper procedures to install the flywheel can crack or damage the crankshaft and or flywheel This not only causes extensive engine damage but can also cause personal injury since broken fragments could be thrown from the engine Always observe and use the following precautions and procedures when installing the flywheel NOTE Before installing the flywheel make sure the crankshaft taper and the flywheel hub are clean dry and completely free of any lubricants The presence of lubricants can cause the flywheel to be over stressed and damaged when the hex flange
263. tang of the throttle shaft plate is against the end of the high speed stop screw See Figure 5B 38 Temporarily clamp in this position 3 Rotate the governor lever and shaft counterclockwise until it stops Use only enough pressure to hold it in that position 4 Check how the end of the throttle linkage aligns with the bushing hole in the governor lever See Figure 5B 40 It should fall in the center of the hole If it doesn t perform the adjustment procedure as follows Figure 5B 40 Throttle Link in Center of Hole B Setting the Initial Adjustment 1 Check the split where the clamping screw goes through the governor lever See Figure 5B 41 There should be a gap of at least 1 32 If the tips are touching and there is no gap present the lever should be replaced 2 Figure 5B 42 Adjusting Governor Shaft Section 5B EFI Fuel System If not already installed position the governor lever on the cross shaft but leave the clamping screw loose Figure 5B 41 Checking Split of Clamp Follow the instructions in Step 2 of Checking the Initial Adjustment then reattach the throttle linkage to the governor lever with the bushing clip It is not necessary to reattach the damper or governor springs at this time Insert a nail into the hole in the top of the cross shaft Using light pressure rotate the governor shaft counterclockwise as far as it will turn then torque the hex nut on the clamping s
264. tator lead to ground using an ohmmeter Perform same test as step 1 above If voltage is 13 8 14 7 and charge rate increases when load is applied the charging system is OK and battery was fully charged If voltage is less than 13 8 or charge rate does not increase when load is applied test stator Tests 2 and 3 If voltage is 28 volts or more stator is OK Rectifier regulator is faulty Replace the rectifier regulator If voltage is less than 28 volts stator is probably faulty and should be replaced Test stator further using an ohmmeter Test 3 If resistance is 0 064 0 2 ohms the stator is OK If the resistance is infinity ohms stator is open Replace stator If the resistance is infinity ohms no continuity the stator is OK not shorted to ground If resistance or continuity is measured the stator leads are shorted to ground Replace stator If the voltage is 14 7 volts or less the charging system is OK The battery is unable to hold a charge Service battery or replace as necessary If voltage is more than 14 7 volts the rectifier regulator is faulty Replace rectifier regulator Section 8 Electrical System and Components Troubleshooting Guide 3 amp Battery Charging System with 70 Watt Lighting Stator NOTE Zero ohmmeters on each scale to ensure accurate readings Voltage tests should be made with engine running at 3000 RPM no load Battery must be good and fully charged 1 With engin
265. tener Torque torque in increments S MIN SIAIG En nl 22 N m 200 in Ib Ge DOE 14 7 N m 130 in Ib o Trimstrardnit SIBI edbesemdaskkuto ee Potest 11 3 N m 100 in Ib Connecting Rod to Crankpin Running Clearance NOW M n cq 0 030 0 055 mm 0 0012 0 0022 in Wir En me cm 0 070 mm 0 0028 in Connecting Rod to Crankpin Side Clearance 0 26 0 63 mm 0 0102 0 0248 in Connecting Rod to Piston Pin Running Clearance 0 015 0 028 mm 0 0006 0 0011 in Piston Pin End I D MISI UU UM CET 17 015 17 023 mm 0 6699 0 6702 in VK Wear En UE 17 036 mm 0 6707 in Crankcase Governor Cross Shaft Bore I D 6 mm Shaft NEW M 6 025 6 050 mm 0 2372 0 2382 in MIS SB Ir RH TEE 6 063 mm 0 2387 in 8 mm Shaft Wi eec 8 025 8 075 mm 0 3159 0 31 79 in Max Wear Mau P cairn canal naeraiieavah caeanan 8 088 mm 0 3184 in Breather Cover Fastener Torque c ccccccccseseececeeeseceeseeeeeeeseeeeeeeeseeaeeees 7 3 N m 65 in Ib Ol Dr ality Pug TONG EE 13 6 N m 10 ft Ib 1 9 Section 1 Safety and General Information Closure Plate Closure Plate Fastener Torque cc cccccccccecesecceeeeeeeeeeeeeeeeeeeeseeaeeeeeeeas 24 4 N m 216 in Ib Crankshaft EINEN AE 0 070 0 590 mm 0 0028 0 0230 in End Play With Thrust Bearing Components 0 070 0 270 mm 0 0028 0 0100 in Except CH25 Engin
266. th those in the brush carrier Section 8 Electrical System and Components Solenoid Shift Electric Starters The following subsection covers the solenoid shift electric starters Much of the information in the proceeding subsection relates to this type starter also so it is not repeated here A Nippondenso or Delco Remy solenoid shift starter may be used The Nippondenso starter is covered first and the Delco Remy starter servicing follows Operation Solenoid Shift Starter When power is applied to the starter the electric solenoid moves the drive pinion out onto the drive shaft and into mesh with the flywheel ring gear When the pinion reaches the end of the drive shaft it rotates the flywheel and cranks the engine Figure 8 38 Style B Commutator End Cap with Brushes When the engine starts and the start switch is released the starter solenoid is deactivated the drive lever 7 Lubricate the drive shaft with Kohler bendix starter MOVes back and the drive pinion moves out of mesh drive lubricant Part No 52 357 01 S Install the with the ring gear into the retracted position drive components following the instructions for servicing the starter drive 6 Install the thru bolts and tighten securely e x Retainer Rear Stop Collar Starter Assembly SC n Insulator Commutator Thru Bolt Armature Figure 8 39 Nippondenso Solenoid Shift Starter 8 27 Section 8 Electrical System
267. the EFI system The chart will enable you to review the entire system in about 10 15 minutes Using the chart the accompanying diagnostic aids listed after the chart and any signaled fault codes you should be able to quickly locate any problems within the system Section 5B EFI Fuel System Bosch EFI Diagnostic Flow Diagram Proceed to Start of Test for retest KEY ON MALFUNCTION INDICATOR LIGHTS ON No REFER TO DIAGNOSTIC AID 1 FAULT CODES ARE FAULT CODES PRESENT REFER TO DIAGNOSTIC AID 2 FAULT CODES CLEAR CODES DOES ENGINE START Yes No REFER TO DIAGNOSTIC AID 3 RUN ON Yes L______y OPERATE AT VARIOUS SPEED LOAD CONDITIONS ARE FAULT CODES PRESENT END OF TEST REFER TO DIAGNOSTIC AID 4 SPEED SENSOR Yes REFER TO DIAGNOSTIC AID 2 FAULT CODES CLEAR CODES CRANK ENGINE DOES MIL GO OFF Yes KEY OFF AND KEY ON LISTEN FOR FUEL PUMP DOES FUEL PUMP CYCLE ON THEN OFF AFTER 1 2 SECONDS LOCATE ELECTRICAL RELAY WHILE HOLDING RELAY KEY OFF AND KEY ON DOES RELAY CYCLE ON THEN OFF AFTER 1 2 SECONDS Proceed to Start of Test for retest Yes Yes REFER TO DIAGNOSITC AID 5 FUEL PUMP No REFER TO DIAGNOSTIC AID 6 RELAY WHILE CRANKING CHECK IGNITION SYSTEM REFER TO DIAGNOSTIC AID 7 IGNITION SYSTEM Yes WHILE CHECKING CHECK INJECTOR FUEL DELIVERY WET S
268. the hex flange nut and fiber washer from the stud terminal Remove the stud terminal with the positive brushes and plastic insulating bushing from the end cap Install the insulating bushing on the stud terminal of the new positive brushes Install the stud terminal into the commutator end cap Secure the stud with the fiber washer and hex flange screw Install the brush holder new negative brushes and self tapping screws Install the brush springs and brushes into the pockets in brush holder Make sure the chamfered sides of the brushes are away from the brush springs 8 25 Section 8 Electrical System and Components NOTE Use a brush holder tool to keep the brushes in the pockets A brush holder tool can easily be made from thin sheet metal See Figure 8 36 Self Brush Springs Tapping Screw Brush A a Holder Negative Negative Brush Stud Terminal wit Positive Brushes Screw Figure 8 35 Style A Commutator End Cap with Brushes Brush Holder Tool Installed Over Brushes and End Cap Sheet Metal Brush Holder Tool Figure 8 36 Brush Holder Tool Style A End Cap Style B End Cap Brush Replacement Starters with Style B end caps have the brushes in a plastic carrier housing separate from the end cap Replacement brushes come preassembled in the carrier housing retained with two carton staples Commutator Service Clean the commutator with a coarse
269. the test If you get the sign and or F again in the retest replace that SAM IMPORTANT Allow 15 20 seconds for the tester to clear and reset itself between tests or if test is interrupted before completion of test cycle Otherwise a false reading may be displayed in the form of a or a faint 8 b DSAM only DSAM firing points are different and testing can only determine if the DSAM is working not the actual firing points Connect the tester in the same manner and start the test If the numbers start advancing the DSAM is working If a dash appears the DSAM is not working Check all of the connections and retest If it still is not working replace the DSAM 8 12 3 Disconnect the yellow and brown tester leads from the long module leads Connect the brown tester lead to the short brown module lead Connect the yellow tester lead to the short yellow or pink module lead See Figure 8 13 Leave the red and green leads connected Repeat step 2 Figure 8 13 The tester is powered by a 9 volt battery Most SAM s are designed to operate down to a minimum of 7 25 volts If the tester battery drops below that level incorrect test readings will result The tester battery should be checked periodically by connecting a DC voltmeter between the red and green lead wires with the tester connected to a SAM Press and hold the test button for a full test cycle F or P appears and then display shuts off
270. ther Two different styles of regulators are used based upon the system involved The Impco Beam regulator is shown in Figure 5A 18 and the Nikki regulator is shown in Figure 5A 19 Although the basic design and operating principles are similar due to system differences the regulators should not be interchanged Section 5A LPG Fuel Systems Figure 5A 19 Nikki Regulator Following are separate sections covering the theory of operation and general service information for each style of regulator Detailed service repair instructions are included in the rebuild kit for each regulator 5A 9 Section 5A LPG Fuel Systems Impco Beam Regulator See Figure 5A 20 L PG vapor enters at point A then passes into primary area B at point 28 where pressure is reduced from up to 250 psi at the tank to 4 5 psi in area B Fuel pressure against diaphragm 2 overcomes spring 3 and as movement increases spring 5 will close lever 6 The primary diaphragm breather not shown in drawing is vented to secondary m eS IIS KH rF 0777777 LLLA N Ne L Ye chamber so that rupture of this diaphragm would direct OI Email Tel fuel into the carburetor l HI N 4 K M N W Fuel now moves through passage E past secondary valve 25 into secondary area C As negative pressure vacuum is created at the carburetor venturi and is transmitted through the dry gas hose to chamber C secondary dia
271. tinuity must exist between all or the armature is bad Insulation Wear limit length 7 6 mm 0 300 in Armature Coil Figure 8 54 Checking Armature Figure 8 52 Checking Brushes 3 Check for continuity between the armature coil Armature segments and the commutator segments See 1 Clean and inspect the commutator outer Figure 8 54 There should be no continuity If surface The mica insulation must be lower than continuity exists between any two the armature is the commutator bars undercut to ensure proper bad operation of the commutator See Figure 8 53 4 Checkthe armature windings insulation for shorting Shift Fork Check that the shift fork is complete and the pivot and contact areas are not excessively worn cracked or broken 8 32 Brush Replacement The brushes and springs are serviced as a set 4 Use Brush and Spring Kit Kohler Part No 25 221 01 S if replacement is necessary 1 Perform steps 1 5 in Starter Disassembly 2 Remove the two screws securing the brush holder assembly to the end cap plate Note the orientation for reassembly later See Figure 8 55 Discard the old brush holder assembly Figure 8 55 Removing Brush Holder 3 Clean the component parts as required 4 The new brushes and springs come preassembled in a brush holder with a protective sleeve that will also serve as an installation tool See Figure 8 56 Figure 8 56 Service Brush Kit 5 Perf
272. tion 3 Looking down the throat of the carburetor check that the throttle plate is in the full throttle position and that the head of the high speed collar stop screw is in contact with the carburetor boss If not loosen the carburetor mounting screws and reposition the carburetor slightly Torque the carburetor mounting screws to 9 9 N m 88 in Ib NOTE If additional adjustment is required loosen the throttle linkage clamp bracket mounting screw set the throttle shaft to the full throttle position against the head of the stop screw and retighten the clamp mounting screw securely See Figure 5A 14 Figure 5A 14 Tightening Throttle Linkage Clamp Bracket Nikki Carburetor 1 Reinstall the rear plug with a new sealing washer Tighten the plug securely 2 Reinstall fuel transfer chamber cover with a new gasket Secure with the three screws 3 Install new carburetor mounting gasket on manifold studs followed by the carburetor and new air cleaner base gasket 4 Reconnect the throttle and choke linkages and the fuel and vacuum lines 5 Reinstall the air cleaner base and breather tube Secure base with two mounting nuts Torque nuts to 9 9 N m 88 in Ib Install the rest of the air cleaner system 5A 8 7 Check to be sure all system connections are tight 8 Reset idle RPM and recheck high idle governed speed after starting and allowing sufficient warm up time Electric Lock Off Filter Assembly
273. tion Switch Voltage Terminal 86 Terminal 287A JD ECU Not used Controlled Ground Terminal 30 Permanent Battery Voltage Figure 5B 14 Relay Connector a Clean the connection and check wiring if circuit was not completed 3 Set meter for DC voltage Touch red tester lead to the 30 terminal in relay connector A reading of 12 volts should be indicated at all times 4 Connect red lead of meter to the 485 terminal in relay connector Turn key switch to the on position Battery voltage should be present a No voltage present indicates a problem in the wiring or at the connector b If voltage is present the wiring to the connector is good Turn ignition switch off and proceed to test 5 to test the relay Terminal 87 Feed to Ignition Coils Fuel Injectors and Fuel Pump Terminal 86 ECU Controlled Ground Terminal 85 Ignition Switch Voltage Terminal 874 Not Used Terminal 30 Permanent Battery Voltage Figure 5B 15 Relay Terminal Details 5 Connect an ohmmeter Rx1 scale between the 85 and 86 terminals in the relay There should be continuity See Figure 5B 15 5B 14 6 Attach ohmmeter leads to the 30 and 87 terminals in relay Initially there should be no continuity Using a 12 volt power supply connect the positive lead to the 85 terminal and touch the negative lead to the 86 terminal When 12 volts is applied the relay should
274. tion later NOTE Impco Carburetor Do not loosen or alter the mounted position of the clamping brackets _ c Loosen the venturi retaining screw on the side and or stop collar on the throttle shaft Each is of the carburetor body and lift out the preset in correlation to a specific position of venturi See Figure 5A 5 the throttle plate shaft or acts as a stop None of these attached components including the throttle plate or shaft requires disassembly or removal for any carburetor servicing All the components on the throttle shaft should be left intact If the settings of any one of these is inadvertently loosened or altered each must be checked reset or performance and operation will be affected Refer to the procedure included in the reassembly installation sequence to check or reset Figure 5A 5 5A 4 Section 5A LPG Fuel Systems 4 Inspect the overall condition of the fuel Nikki Carburetor enrichment hose attached to the carburetor It 1 Turn off fuel supply at tank must be free of cracks deterioration and damage Disconnect the fuel enrichment hose 2 Remove the air cleaner breather hose fuel line from the carburetor fittings to clean or check vacuum hose choke and throttle linkages condition as required See Figure 5A 6 Replace Remove the nuts carburetor and gaskets from with a new Kohler high pressure hose LP rated if the engine Discard the gaskets the condition is questionable in any way Secure ne
275. to be replaced Spark Plugs EFI engines are equipped with Champion RC12YC Kohler Part No 12 132 02 S resistor style spark plugs Equivalent alternate brand plugs can also be used but must be a resistor style plug or permanent damage to the ECU will occur in addition to affecting operation Proper spark plug gap is 0 76 mm 0 030 in Wiring Harness The wiring harness used in the EFI system connects the electrical components providing current and ground paths for the system to operate All input and output signaling occurs through a special all weather connector that attaches and locks to the ECU see Figures 5B 23 5B 24 and 5B 25 Figure 5B 23 35 Pin MA 1 7 Metal Cased ECU Connector and O Ring Figure 5B 24 24 Pin MSE 1 0 Plastic Cased ECU Connector Figure 5B 25 32 Pin MSE 1 1 Plastic Cased ECU Connector The condition of the wiring connectors and terminal connections is essential to system function and performance Corrosion moisture and poor connections are more likely the cause of operating problems and system errors than an actual component Refer to the Troubleshooting Electrical section for additional information Battery Charging System EFI engines are equipped with either a 15 or 25 amp charging system to accommodate the combined electrical demands of the ignition system and the specific application Charging system troubleshooting information is provided in Section 8
276. ttle against the idle stop On some EFI engines there is a dampening spring on the end of the idle speed screw The dampening spring if used should be fully compressed and the tab on the throttle lever in direct contact with the speed screw Adjust the idle speed to 1500 RPM using a tachometer 6 Shut off engine 7 Locate the service connector plug in the wiring harness 35 Pin MA 1 7 Metal Cased ECU Connect a jumper wire from the TPS initialization pin 8 gray wire to the ground pin black wire or use jumper plug SPX Part No KO3217 7 with red jumper wire See Figure 5B 8 Section 5B EFI Fuel System 24 Pin MSE 1 0 Plastic Cased ECU b If light stays on or blinking ceases prematurely Connect a jumper wire from the TPS initialization the procedure was unsuccessful and must be pin 24 violet wire to the battery voltage pin red repeated Possible causes for unsuccessful wire or use jumper plug SPX Part No learning may be 1 Movement occurred in KO3217 9 with blue jumper wire See Figure either the TPS or throttle shaft during 5B 9 procedure 2 Crankshaft movement rotation was detected by the speed sensor during procedure 3 Throttle plate position was out of learnable range recheck the 1500 RPM idle speed adjustment or 4 Problem with ECU or TPS 9 When the initialization procedure has been successfully completed turn off the key switch remove the jumper wire or connector and remove the
277. ughly or stalls at low idle speed check the following areas before adjusting or disassembling the carburetor e Make sure the fuel tank is filled with clean fresh gasoline e Make sure the fuel tank cap vent is not blocked and that it is operating properly e Make sure fuel is reaching the carburetor This includes checking the fuel shut off valve fuel tank filter screen in line fuel filter fuel lines and fuel pump for restrictions or faulty components as necessary e Make sure the air cleaner base and carburetor are securely fastened to the engine using gaskets in good condition e Make sure the air cleaner element including precleaner if equipped is clean and all air cleaner components are fastened securely e Make sure the ignition system governor system exhaust system and throttle and choke controls are operating properly If the engine is hard starting runs roughly or stalls at low idle speed it may be necessary to adjust or service the carburetor High Altitude Operation When operating the engine at altitudes of 1500 m 5000 ft and above the fuel mixture tends to get over rich This can cause conditions such as black sooty exhaust smoke misfiring loss of speed and power poor fuel economy and poor or slow governor response To compensate for the effects of high altitude special high altitude jet kits are available The kits include a new main jet slow jet where applicable necessary gaskets and
278. ure 11 56 Installing Breather Reed Assembly Ignition Modules 4 Insert the breather filter into position in the crankcase Make sure no filter strands are on the sealing surface See Figure 11 57 5 Install the new breather gasket Figure 11 55 Connect Leads on SMART SPARK Ignition Modules Install Breather Cover and Inner Baffles RTV sealant was used on early models between the breather cover and the crankcase A gasket with imprinted sealant beads is now used and recommended Install as follows Figure 11 57 sui New Breather Filter 6 Carefully position the breather cover on the crankcase Install first two hex flange screws at positions shown in Figure 11 58 and finger tighten 1 Be sure the sealing surfaces of the crankcase di at this time and breather cover are clean of old gasket material or RTV sealant Do not scrape the surfaces as this could result in leakage 2 Check to make sure there are no nicks or burrs on sealing surfaces 3 Install the hex flange screw breather reed retainer and breather reed onto the crankcase as shown in Figure 11 56 11 16 Section 11 Reassembly Install Blower Housing and Outer Baffles NOTE Do not completely tighten screws until all items are installed to allow shifting for hole alignment 1 Connect the plug to the key switch in the blower housing if so equipped 2 Slide the blower housing into position over the front edge of the inner baffles Se
279. ust be in contact with the carburetor boss from the back hose fitting side preventing any further rotation over center Set or adjust the stop collar as required See Figure 5A 12 Figure 5A 10 Tightening Idle Speed Clamp 6 Zeg Mounting Screw 9 High Speed Stop Collar 4 Resetthe idle speed adjustment screw back to the original position High Speed Stop Collar Position 1 Make sure the idle speed clamp position has already been checked or properly set Figure 5A 12 Adjusting Setting Stop Collar 2 Rotate and hold the throttle shaft so the throttle 4 Tighten the screw securely plate is fully open perfectly vertical See Figure 9A 11 NOTE After the idle speed clamp bracket and the high speed stop collar positions have been set check that the throttle shaft pivots freely without binding or restriction Throttle Linkage Clamp Bracket Position Carburetor must be assembled to engine with linkage attached to set this position 1 The throttle linkage clamp bracket should be positioned as shown in Figure 5A 13 on the idle High Speed Stop speed clamp bracket side of the throttle shaft Collar Figure 5A 11 Full Throttle Position Throttle Linkage ad Clamp Bracket Figure 5A 13 Throttle Linkage Clamp Bracket Position 5A 7 Section 5A LPG Fuel Systems 2 Manually move the governor lever with the throttle linkage connected toward the carburetor as far as it will go Hold it in this posi
280. w hose using new clamps 3 Remove the fuel transfer chamber cover by removing the three screws See Figure 5A 3 Carefully remove the cover and gasket Discard the gasket 4 The main jet is fixed and nonadjustable but may be accessed for cleaning by removing the rear plug and sealing washer Discard the washer 5 In order to clean the off idle transfer passages and carburetor thoroughly use a good carburetor cleaner and follow the manufacturer s instructions Blow clean compressed air through the passages and make sure all are open before reassembling Do not use wire or metal objects to clean passages or carburetor body Figure 5A 6 5 Cl Il part rad dicamus LPG Carburetor Inspection RE eege 1 Inspect the carburetor body and removable ebat following the ee me venturi Impco carburetor for cracks holes and ow clean compressed air through all the other wear or damage passages Do not poke or probe into the load OCR A SCD amaga anne Bene resulting 2 Check the choke shaft Nikki carburetor only and in serious operational problems See Figure 5A 7 iBsdbretia ehaftforweetand i aemovemenr NOTE Do not attempt to disassemble or remove either shaft from the carburetor body including the mounted clamp brackets on Impco style carburetors The screws attaching the choke and throttle plate to their respective shafts are staked or bonded to prevent loosening The plate s and shaft s are not available separately
281. while monitoring the voltage reading on the voltmeter If the voltage drops below 7 5 at any time during the cycle the 9 volt tester battery must be replaced Use an extended life alkaline battery To replace the battery remove the outer set of screws on the faceplate and carefully lift the panel from the body Unplug the connector and pull battery with mounting tape off the back of the tester Attach the connector to the new battery and mount the battery to the case with double backed tape Reinstall the faceplate and secure with the four screws Battery Charging System General Most engines are equipped with a 15 or 20 amp regulated charging system Some have a 25 amp regulated charging system See Figure 8 14 for the 15 20 25 amp charging system diagram Some engines utilize a 3 amp unregulated system with optional 70 watt lighting circuit Refer to Figure 8 18 NOTE Observe the following guidelines to avoid damage to the electrical system and components Section 8 Electrical System and Components e Make sure the battery polarity is correct A negative ground system is used wiring harness plug before doing any electric Disconnect the rectifier regulator plug and or the welding on the equipment powered by the engine Also disconnect all other electrical accessories in common ground with the engine e Prevent the stator AC leads from touching or shorting while the engine is running This could dam
282. xtremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Do not start the engine near spilled fuel Never use gasoline as a cleaning agent General These engines are equipped with fixed main jet carburetors manufactured by Keihin to Kohler specifications Most have automatic chokes and fuel shut off solenoids Keihin carburetors with accelerator pump features are standard on many models and are furnished as an option on other CH applications where improved performance is required during periods of rapid acceleration Both types are almost identical except for the accelerator pump parts shown in the inset in Figure 5 8 Most information in the following pertains to both type carburetors with differences pointed out or shown wherever pertinent Troubleshooting Carburetor Related Causes Possible Cause Probable Remedy 1 Engine starts hard runs roughly or Low idle fuel mixture some models speed improperly adjusted stalls at idle speed Adjust the low idle speed tab then adjust the low idle fuel needle Engine runs rich indicated by Clogged air cleaner Clean or replace black sooty exhaust smoke Choke partially closed during operation Check the choke lever
283. y sheared 2 Speed Sensor Ring Gear Related a Damaged teeth b Varying gap gear loose out of alignment 3 Engine Wiring Harness Related 35 Pin MA 1 7 Metal Cased ECU a Pin circuits 3 and or 21 wiring or connectors b Shielding for pin circuits 3 and or 21 damaged or not properly grounded c Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output d Pin circuits 3 and or 21 routed near noisy electrical signals coils spark plug lead plug connector 3 Engine Wiring Harness Related 24 Pin MSE 1 0 Plastic Cased ECU a Pin circuits 9 and or 10 wiring or connectors b Shielding for pin circuits 9 and or 10 damaged or not properly grounded c Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output d Pin circuits 9 and or 10 routed near noisy electrical signals coils spark plug lead plug connector 3 Engine Wiring Harness Related 32 Pin MSE 1 1 Plastic Cased ECU a Pin circuits 9 and or 10 wiring or connectors b Shielding for pin circuits 9 and or 10 damaged or not properly grounded c Poor or improper grounds in system battery ECU oxygen sensor shielding fuel pump ignition output d Pin circuits 9 and or 10 routed near noisy electrical signals coils spark plug lead plug connector Section 5B EFI Fuel System 4 ECU Harness Related a ECU to harness connection
284. ystem and Components Figure 8 62 Installing Thrust Washer Figure 8 64 Removing Retaining Clips 10 Starter reassembly when replacing the Brushes b Position each of the brushes back in their slots Brush Holder Assembly so they are flush with the I D of the brush holder assembly Insert the Brush Installation a Hold the starter assembly vertically on the end Tool SPX Part No KO3226 1 with extension housing and carefully position the assembled or use the tube described above from a prior brush holder assembly with the supplied brush installation through the brush holder protective tube against the end of the assembly so the holes in the metal mounting commutator armature The mounting screw clips are up out holes in the metal clips must be up out Slide the brush holder assembly down into place c Install the brush springs and snap on the four around the commutator and install the positive retainer caps See Figure 8 65 brush lead grommet in the cutout of the frame See Figure 8 63 The protective tube may be saved and used for future servicing Figure 8 65 Brush Installation Tool with Extension d Hold the starter assembly vertically on the end Figure 8 63 Installing Brush Holder Assembly with housing and carefully place the tool with Supplied Tube extension and assembled original brush holder assembly onto the end of the armature shaft Starter reassembly when not replacing the Brushes Slide the

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