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TP-2480 TH16, TH18 Service Manual

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1. i Aluminum e 1 7 15 2 9 26 36 5 0 44 2 0 18 3 2 28 5 8 51 K i a 9 7 86 4 0 35 5 7 50 9 9 88 14 0 124 16 5 146 6 8 60 13 6 120 24 4 216 33 9 300 40 7 360 17 0 150 Tightening Torque N m ft Ib or 10 Property Class Noncritical Fasteners Ce amp if Aluminum 27 1 47 5 35 66 4 49 81 4 60 33 9 25 47 5 es 82 7 Gen 116 6 86 139 7 103 61 0 45 76 4 55 131 5 97 184 4 136 219 7 162 94 9 70 Torque Conversions N m sin Ib x 0 113 N m ft Ib x 1 356 in Ib Nm x 8 85 ft Ib N m x 0 737 Section 1 Safety and General Information Tightening Torque N m in Ib or 20 Bolts Screws Nuts and Fasteners Assembled Into Cast Iron or Steel Q Grade 2 2 3 20 3 6 32 3 6 32 7 9 70 9 6 85 17 0 150 18 7 165 29 4 260 33 9 300 47 5 35 61 0 45 67 8 50 94 9 70 101 7 75 135 6 100 149 2 110 189 8 140 199 3 150 271 2 200 Grade 2 or 5 Fasteners into Aluminum 18 7 165 22 6 200 39 6 350 101 7 75 108 5 80 237 3 175 311 9 230 TH16 amp TH18 Section 2 Special Tools These 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 satisfaction by decreasin
2. 7 5 TH16 amp TH18 Section 8 Electrical System and Components This section covers the operation service and repair of 2 Remove the plug and check its condition See the electrical system components Systems and Inspection following this procedure Replace the components covered in this section are plug if necessary Spark Plugs NOTE Do not clean spark plug in a machine Battery and Charging System using abrasive grit Some grit could remain in the spark plug and enter the Electronic CD Ignition System engine causing extensive wear and Electric Starter damage Spark Plugs 3 Check the gap using a wire feeler gauge Adjust Engine misfire or starting problems are often caused the gap to 0 76 mm 0 030 in by carefully by a spark plug that has improper gap setting or is in bending the ground electrode See Figure 8 1 poor condition Wire Gauge The engine is equipped with the following spark plugs Type Champion RC12YC or equivalent 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 Ground debris out of the engine Electrode 0 76 mm 0 0
3. Install Air Cleaner 1 Install a new base plate gasket and base plate Secure to the carburetor with three hex flange screws tightened to 9 9 N m 88 in Ibs torque See Figure 11 56 Install new seals on base plate studs one long seal on top tank version Figure 11 56 Install Air Cleaner Base Plate Std Shown 11 18 Section 11 Reassembly 2 Install precleaner and paper element 3 Align tank over stud holes then install and secure with five hex flange screws 3 Install inner cover and secure with two wing nuts one on top tank type cleaner See Figure 11 57 4 Install air cleaner cover after top tank is secured Install Drain Plugs and Oil Filter 1 install oil drain plugs and securely tighten See Figure 11 59 Figure 11 57 Installing Inner Cover Wing Nut Top Tank Shown 4 Install air cleaner cover and secure with retaining knob standard type only on top tank type install Figure 11 59 Reinstalling Oil Drain Plugs cover only after tank is installed 2 Prefill oil filter following instructions in Section 6 NOTE Refer to Section 4 for air cleaner components 3 Install prefilled oil filter Turn clockwise until tight Install Fuel Tank Top Mounted 1 Install hose clamp on fuel line Connect line to fitting on fuel shut off valve and then slide clamp over fitting and release See Figure 11 58 4 Addoilto bring level up to full mark on dipstick Connect Spark Plug Leads
4. 1 Connect the leads to the spark plugs See Figure 11 60 Figure 11 58 Connecting Fuel Line to Shut Off Valve Top Mounted Tank Figure 11 60 Connect Spark Plug Leads 2 Place tank on top of engine and slide it into position back toward PTO end Be sure grommet aligns with hole in base std type 11 19 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 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 11 20 Testing the Engine It is recommended that the engine be operated on the test stand or bench prior to installation in the piece of equipment de Set the engine up on a test stand Install an oil pressure gauge in the location normally used for Oil Sentry Refer to Lubrication System section Figure 6 6 Start the engine and check to be certain that oil pressure 20 psi or more is present Run the engine for 5 10 minutes between idle and midrange Adjust the carburetor idle speed setting as necessary Make sure the maximum engine speed does not exceed 3750 RPM no load Adjust the t
5. KOHLER jns SERVICE MANUAL OHC 16 18 HP Horizontal Crankshaft Contents Section 1 Safety and General Information e ceeciieeeeeeeee ecce eren eene nnnnn Section 2 CN TEEN Section EHE rune Section 4 Air Cleaner and Air Intake System eee enne Section 5 Fuel System and Governor essei e eeeeeeeee esee enne tease nnne nnne near annee enn n nnn Section 6 Lubrication System io es cioetrse eere ea C2na noce NE Iso consc cet oa oS poen Eo ENEE ee Section 7 Retractable Starter 5 eege ria rati dtl n ups QV NEU Oan NEN evi Section 8 Electrical System and Components Section 9 Disassombly crap er eru t e2d rx ex Suse UK X xl NI ESTEE NN ENS FR Y Qa DE VEYR E VE PRU ER eCS E esp ua a P RN UR Section 10 Inspection and Reconditioning eese nennen nnn Section 11 Reassembly ois sss cscs e anos eec er rape biE eo aea Eeer TH16 amp TH18 Section 1 Safety and General Information Safety Precautions To insure safe operations 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 inj
6. 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 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 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 CAUTION 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 1 2 Section 1 Safety and General Information Engine Identification Numbers When ordering parts or in any c
7. Figure 8 12 Assembling inner Half of Tooi Around Armature Shaft and Retaining Ring 5 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 18 mm to turn the center screw clockwise see Figure 8 13 The resistance against the center screw will tell you when the retaining ring has popped out of the groove in the armature shaft Figure 8 13 Holding Tooi and Turning Center 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 ZS Figure 8 14 Assembling Larger inner Half Around Spring Retainer 7 The splines should have a light film of lubricant Relubricate as necessary with Kohler bendix starter lubricant Part No 52 357 01 Reinstall or replace the drive components assembling them in the same sequence as they were removed Retaining Ring Installation Position the retaining ring in the groove in one of the inner halves of tool 25 761 18 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
8. Remove Cup From Retractable Starter Equipped Models 2 Useaflywheel puller to separate flywheel from crankshaft taper See Figure 9 17 Figure 9 17 Using Puller to Remove Flywheel NOTE Tension spring located inside will POP flywheel free of crankshaft See Figure 9 18 Figure 9 18 Spring Inside Will POP Flywheel Off 3 Use needle nose pliers or side cutter to grasp and remove flywheel key See Figure 9 19 Figure 9 19 Removing Flywheel Key From Crankshaft 9 6 Section 9 Disassembly Remove Stator 2 Onall other engines remove the ten hex flange 1 Note routing of all wiring and harnesses to Screws securing covers reassemble in same position later TAM 3 Remove the dipstick 2 Remove the two hex flange screws securing stator to crankcase See Figure 9 20 4 Remove the valve covers and gaskets on both sides Discard the gaskets See Figures 9 22 9 23 and 9 24 Figure 9 20 Removing Stator 3 Remove the stator and let it hang loose Remove Timing Belt 1 Remove the two hex flange screws securing the idler pulley to the crankcase 2 Remove idler pulley and the timing belt See Figure 9 21 Screws Figure 9 21 Remove Idler Pulley to Remove Timing Belt Remove Valve Covers 1 On engines with top mounted fuel tank remove the five 7 16 adapter studs and the five hex GER flange screws securing covers Figure 9 24 Removing Cover and Fuel Pump Assembly
9. or stalls at are securely fastened to the engine using gaskets low idle speed check the following areas before in good condition adjusting or disassembling the carburetor Make sure the air cleaner element is clean and all Make sure the fuel tank is filled with clean fresh air cleaner components are fastened securely gasoline Make sure the ignition system governor system Make sure the fuel tank cap vent is not blocked exhaust system and throttle and choke controls and that it is operating properly are operating properly Make sure fuel is reaching the carburetor This If the engine is still hard to start runs roughly or stalls includes checking the fuel shut off valve fuel tank at low idle speed it may be necessary to service the filter screen in line fuel filter fuel lines and fuel carburetor pump for restrictions or faulty components as necessary 5 5 Section 5 Fuel System and Governor Fuel Shut off Solenoid Some carburetors are equipped with an optional fuel shut off solenoid The solenoid is installed in place of the bowl retaining screw The solenoid has a spring loaded pin that retracts when 12 volt current is applied to the lead The pin blocks the main fuel jet and prevents fuel from entering the carburetor when it is extended Below is a simple test made with the engine off that can determine if the solenoid is functioning properly 1 Shut off the fuel and remove the solenoid from the c
10. use new carburetor and intake manifold gaskets 5 9 Section 5 Fuel System and Governor Governor When the engine is at rest and the throttle is in the fast position the tension of the governor spring holds the throttle plate open When the engine is operating and the governor assembly is rotating the force applied against the cross shaft tends to close the throttle plate The governor spring tension and the force applied by the bushing balance each other during operation to maintain engine speed General The 2 side camshaft is equipped with a centrifugal flyball mechanical governor It is designed to hold the engine speed constant under changing load conditions The governor works as follows Centrifugal force acting on the rotating governor assembly causes the flyballs to move outward as speed increases When load is applied and the engine speed and governor speed decrease the governor spring tension moves the governor lever to open the throttle plate wider This allows more fuel into the engine increasing engine speed As speed reaches the governed setting the governor spring tension and the force applied by the bushing will again offset each other to hold a steady engine speed Asthe flyballs move outward they exert increasing pressure against the cover and bushing The bushing contacts the yoke on the cross shaft causing the shaft to rotate One end of the cross shaft protrudes through the c
11. 0 psig The tester should indicate a change to continuity switch closed down to 0 psig 4 Replace the switch if it does not operate as specified TH16 amp TH18 Section 7 Retractable 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 Starter Housing Figure 7 2 Removing Retractable Starter To Install Starter 1 Install the retractable starter and five hex flange screws to blower housing Leave the screws Pawi Dog slightly loose 2 Pullthe starter handle out until the pawls engage in the drive cup Hold the handle in this position Center Screw and tighten the screws securely Figure 7 1 Retractable Starter Exploded View Rope Replacement The rope can be replaced without complete starter To Remove Starter P p p disassembly 1 Remove the five hex flange screws securing the starter to blower housing See Figure 7 2 1 Remove the starter from the engine blower housing 2 Remove the starter 2 Pull the rope out approximately 12 and tie a temporary slip knot in it to keep it from retracting into the starter See Figure 7 3 7 1 Section 7 Retractable Starter E Figure 7 3 Removing Starter Handle Figure 7 4 Installing Rope 3 Remove the rope retai
12. 1 Side 9 7 Section 9 Disassembly Remove 1 Side Camshaft and Rocker Arms 1 Turn the camshaft until tension is off the rocker arms 2 Remove the C clip on inside of rocker box using two small screwdrivers 3 Remove the camshaft and thrust washer See Figure 9 25 aman pipa ie omm E Figure 9 25 Removing Camshaft on 1 Side 4 Remove the two hex flange screws from the rocker arm shaft See Figure 9 26 Figure 9 26 Removing Rocker Arm Shaft Screws 5 Lift rocker arm assembly off valve mechanism See Figure 9 27 Figure 9 27 Removing Rocker Arm Assemblies 2 Side Shown Remove 2 Side Camshaft and Rocker Arms 1 Turn the camshaft until tension is off the rocker arms and the coiled spring pin is visible in the governor body See Figure 9 28 Figure 9 28 42 Side Camshaft Rocker Arm Detail 2 Using a small punch drive the coiled spring pin down about 5 8 See Figure 9 29 Figure 9 29 Driving Coiled Spring Pin Down 9 8 Section 9 Disassembly 3 Turn the camshaft 180 Remove Governor Yoke and Cross Shaft 1 Remove the two hex socket head screws from 4 Grasp protruding end of the coiled spring pin with the governor yoke See Figure 9 32 vise grip pliers Pull the pin out of camshaft See Figure 9 30 2 Remove the governor cross shaft See Figure 9 32 Figure 9 30 Removing Coiled Spring Pin Figure 9 32 Removing Gover
13. End Crank in Engine 0 cee eee cece eee creer eeeeee tees tereennenenes 0 015 mm 0 0006 in Entire Crank in V Blocks ccccecceccceseeseeeseeeeeeseseeeeceesesetesenees 0 010 mm 0 0004 in Cylinder Bore Cylinder Bore D New ULL 73 006 73 031 mm 2 8742 2 8752 in RRG KEE 75 025 75 050 mm 2 9537 2 9547 in Max Wear Limit AVG ese rte en eere Eb Ee e oa este Ostet te Eee tol 73 07 mm 2 8767 in le KE EE 75 09 mm 2 9563 in Max Out of Round essssssesssseeeeeneee enne nennen enne 0 13 mm 0 005 in Max E LEE 0 13 mm 0 005 in Electric Starter Starter Mounting Fastener Torque sssssesresressrreressisnensssssrnsrsnnrinsnes 7 9 N m 70 in Ib Timing Belt Belt Tensioner Mounting Screw orgue sssssnssnssrinsinsinsrresinnrennnnno 7 3 N m 65 in Ib Belt Tension Torque enapan ent aaae aeiaaeeao lakao aieka titia 3 4 4 5 N m 30 40 in Ib Fan Flywheel Fan Fastener Torque sessssessssseeeeeeeee nee 9 9 N m 88 in Ib Flywheel Retaining Screw Torque sse 66 4 N m 49 ft Ib Governor Governor Cross Shaft to Crankcase Running Clearance esssssssessseeeeeeneneen eene 0 013 0 075 mm 0 0005 0 0030 in Governor Cross Shaft O D New gie eie tte e e qoe eg a sete ids dade d Pater are EO 7 975 8 012 mm 0 3140 0 3154 in Max Wear mit 1 ocio eet ot reme ete tee 7 96 mm 0 3134 in 1 9 Section 1 Safety and General Information Governor Cont Gov
14. I D KEE 8 025 8 050 mm 0 3159 0 3169 in Max Wear Limit E 8 07 mm 0 3177 in Breather Cover Mounting Fasteners ssessseseee 5 6 N m 50 in Ib Oll Drain Plugs err ente ite eet 13 6 N m 10 ft Ib Crankcase Halves Mounting Screw Torque eesssesssssesissersnsenresenene 24 4 N m 216 in Ib Crankshaft EMG GE E Not Adjustable Crankshaft Sleeve Bearing D News re ertet etie ated EE 45 071 45 111 mm 1 7744 1 7760 in Max Wear limit neo eee fet tees 45 12 mm 1 7764 in Crankshaft to Sleeve Bearing Running Clearance New EEN 0 030 0 090 mm 0 0012 0 0035 in 1 8 Section 1 Safety and General Information Crankshaft Cont Flywheel End Main Bearing Journal O Dz New a hee lites e eet eda NEE tette 45 021 45 041 mm 1 7725 1 7735 in O D Max Wear Limit 44 95 mm 1 7696 in EE EE 0 02 mm 0 0008 in Max Out of Round sssssssssseeeeeeeen enne nehmen nennen 0 02 mm 0 0008 in PTO End Main Bearing Journal QD EE 45 021 45 041 mm 1 6107 1 6116 in O D Max Wear Limit esse 44 95 mm 1 7696 in Max KT 0 02 mm 0 0008 in Max Qut of Ro nd Seege Regie tete te efits 0 02 mm 0 0008 in Connecting Rod Journal OD SNOW insit et her ree etie eR eee 31 948 31 966 mm 1 2578 1 2585 in OD Max Wear Uimp 31 93 mm 1 2571 in Maxi EI ERE 0 02 mm 0 0008 in Max e Tee ie ree tenir ttr ge teer enn 0 02 mm 0 0008 in Crankshaft T I R PTO
15. Install valley baffle and wiring 13 Install rectifier regulator 14 Install governor camshaft 2 side 15 Install camshaft 1 side 16 Install timing belt 17 Install flywheel 18 Install ignition modules 19 Set valve clearance 20 Install valve cover 1 side 21 Install valve cover 2 side OANOaARWN Install dipstick Install spark plugs Install cylinder side baffles Install electric starter motor Install blower housing Install grass screen or retractable starter Install carburetor and controls Install muffler if so equipped Install air cleaner Install fuel tank if so equipped Install drain plugs and pre filled oil filter Connect spark plug leads Install Valve Train 1 2 Install the valve seals Lubricate the valve guides and stems 3 Turn upper crankcase half upside down in stand Figure 11 1 Compress Valve Springs and Install block on work bench Install valves in guides using valve lapping tool Install valve blocking tools and cover plate then turn crankcase half over again Install retainers springs and spring caps Compress valve springs and install valve keepers See Figure 11 1 Keepers 11 1 Section 11 Reassembly Install Connecting Rods with Pistons and Rings 1 Turn crankcase half upside down again and remove cover plate and valve blocking tools See Figure 11 2 LP T 4 Figure 11 2 Removing Valve Blocking Tool
16. NOTE The cylinders are numbered on the crankcase Make sure to install piston connecting rod and end cap into its appropriate cylinder bore as previously marked at disassembly Do not mix 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 2 Stagger the piston rings in the grooves until the end gaps are 120 apart The oil ring rails should also be staggered 3 Align the match marks and assemble the rod caps to the connecting rods with the screws finger tight 4 Lubricate cylinder bores piston and rings 5 Compress the rings with piston ring compressor Push piston through until crown just protrudes from bottom of compressor to pilot inside cylinder bore 6 Position piston connecting rod assembly see Reconditioning Section 10 in correct bore with FLY mark toward flywheel end and match marks facing outside 7 Hold the connecting rod in alignment with one hand and bump the rod cap with the heel of your other hand to move the piston and rings through the compressor into the cylinder 8 Repeat procedure with the other piston rod assembly Install Crankshaft Install crankshaft assembly see Reconditioning Section 10 as follows See Figure 11 3 1 Push the pistons to the top of the cylinder and then remove the rod caps Figure 11 3 Installing Cr
17. Remove the hex flange nut and fiber washer from the stud terminal Remove the stud terminal with positive brushes and plastic insulating bushing from the end cap 4 Reinstall the insulating bushing to the new stud terminal with positive brushes Install the stud terminal with bushing into the commutator end cap Secure the stud with the fiber washer and hex flange screw 5 Install the brush holder new negative brushes and self tapping screws 6 Install the brush springs and brushes into the pockets in brush holder Make sure the chamfered sides of brushes are away from the brush springs 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 16 Figure 8 16 Brush Holder Tool For UT Starters UT Commutator Service Clean the commutator with a coarse 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 UT Starter Reassembly 1 Place the thrust washer over the drive shaft of armature 2 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 8 15 Section 8 Electrical System and Components 3 Install the drive end cap over the drive shaft Make sure the match marks on the end cap and starter frame are aligned See Fi
18. The stator is mounted on the crankcase behind the flywheel Should the stator have to be replaced follow the procedures in Section 9 Disassembly See Figure 8 7 for 15 amp stator or Figure 8 8 for 25 amp stator Rectifier Regulator The rectifier regulator is mounted on the blower housing on standard engines and on the valley baffle on top tank engines To replace it disconnect the plug remove the two mounting bolts and ground strap DC Voltmeter Rectifier Regulator Flywheel Stator Ammeter Battery Figure 8 9 Connections for Testing Charging System 8 11 Section 8 Electrical System and Components Electric Starting Motors Some engines in this series use inertia drive type starting motors while others use solenoid shift type The inertia drive types are covered first and the solenoid shift type is covered starting on page 8 16 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 Ifthe engine develops sufficient speed to disengage the inertia drive type starter but does not keep running a false start the engine rotation must be allowed to come to a complete stop before attempting to restart the engine If the starter is engaged while the flywheel is rotating the starter pinion and flywhe
19. Then carefully inspect each valve for defects such as warped heads excessive corrosion or worn stem ends Replace valves found to be in bad condition A normal valve and valves in bad condition are shown in the valve illustrations on the following pages Inspection and Service 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 inserts in the upper crankcase area for evidence of deep pitting cracks or distortion Check the clearance of the valve stems in guides See Figure 10 7 for valve details and specifications Exhaust Valve Intake Valve F E F E 2 Intake NL ERA 1 Exhaust Insert G G Insert ff Seat Angle Insert Area Insert LD None None Guide Depth in crankcase 8 63 9 23 mm 8 63 9 23 mm Guide I D 6 038 6 058 mm 6 038 6 058 mm Valve Head Diameter 29 18 29 43 mm 26 30 26 70 mm Valve Face Angle 45 45 Valve Margin Min 1 10 mm 1 13 mm Valve Stem Diameter 5 982 6 000 mm 5 970 5 988 mm zommoou Figure 10 7 Valve Details 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 i
20. air cleaner base from carburetor elbow by removing the three hex flange screws See Figure 9 4 Remove the base plate Some early engines may also have a spacer between the base plate and elbow Figure 9 4 Removing Base Plate Standard Type Shown 3 Discard the base plate to carburetor gasket Remove Fuel Tank If So Equipped 1 Onengines equipped with the top mounted fuel tank remove the five hex flange screws securing the tank to the valve covers 2 Lift the tank and pull it forward Fuel line will come with it See Figure 9 5 Figure 9 5 Removing Engine Mounted Fuel Tank 3 Loosen hose clamp holding fuel line to the fuel shut off valve then separate hose and remove fuel tank 9 2 Section 9 Disassembly Remove Muffler Disconnect Carburetor Linkage 1 Onengine so equipped remove the muffler from 1 Loosen the hose clamp holding the upper end of engine by removing the four hex flange nuts 2 the breather hose on the flange of the carburetor on each side with a 13 mm flex socket See elbow Pull the end off the flange See Figure 9 7 Figure 9 6 L Figure 9 7 Disconnecting Breather Hose Figure 9 6 Removing Muffler 2 Carefully disconnect the flanged lower end of the 2 Remove and discard the two exhaust gaskets hose from the breather cover Remove the hose 3 Loosen the hex flange nut and slide the governor lever off of the governor shaft j Screw Bushing f Governor Lev
21. amp Regulated Battery Charging System Without Panel 8 8 Section 8 Electrical System and Components Rectifier Regulator 15 Amp Stator Figure 8 7 15 amp Stator and Rectifier Regulator Rectifier Regulator AC Leads 25 Amp Stator Figure 8 8 25 amp Stator and Rectifier Regulator 8 9 Section 8 Electrical System and Components Troubleshooting Guide 15 25 amp Battery Charging System 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 fully charged Battery Continuously Charges at High Rate 8 10 Trace B lead from rectifier regulator to key 1 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 r
22. are used in these engines Inspection and Service Check bearing area big end for excessive wear score marks running and side clearances refer to Section 1 Specifications Tolerances and Special Torque Values Replace rod and cap if scored or excessively worn 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 Oil Seals in Crankcase Halves Always install new oil seals when reconditioning an engine There are two different seals for the crankshaft Lubricate these with engine oil before installation Use a seal driver and press to the depth shown in Figure 10 13 Install crankshaft oil seals after the crankshaft assembly is in position refer to Section 11 Reassembly 6 0 mm 0 2362 in Figure 10 13 Crankshaft Oil Seals The oil seals for the camshafts can be installed in the upper crankcase assembly at this time Lubricate the seals with engine oil and use a seal driver to the depth shown in Figure 10 14 Section 10 Inspection and Reconditioning 1 5 mm 0 0591 in K Camshaft Oil Seals Apply Oil Before Assembly Figure 10 14 Camshaft Oil Seals The governor shaft oil seal can also be installed
23. covers 17 Remove 1 side camshaft OMONOARWN gt 18 Remove rocker arms 19 Remove 2 side camshaft 20 Remove governor yoke 21 Remove rectifier regulator 22 Remove valley baffle 23 Remove crankcase breather 24 Remove Oil Sentry Switch 25 Remove oil filter adapter 26 Separate crankcase halves 27 Remove oil pump parts 28 Remove oil pressure relief parts 29 Remove connecting rods 30 Remove crankshaft 31 Disassemble crankshaft 32 Remove piston assemblies 33 Remove valve train parts 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 om Figure 9 1 Disconnect Both Spark Plug Leads 9 1 Section 9 Disassembly Turn Fuel Off 1 Turn fuel shut off valve to off position Vertical position is off See Figure 9 2 Figure 9 2 Turn Fuel Off Drain Oil From Crankcase and Remove Oil Filter 1 Remove oil fill cap and one of the oil drain plugs See Figure 9 3 for location of drain on oil filter side Figure 9 3 Removing Oil Drain Plug and Filter 2 Allow ample time for all of the oil to drain from the crankcase and oil filter 3 Remove the oil filter by turning it in a counterclockwise direction with a filter wrench Discard filter Remove Air Cleaner Assembly 1 Remove air cleaner components from base plate Refer to Section 4 2 Remove the
24. engine with heat shields or neutral guards removed 1 1 Section 1 Safety and General Information 44 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 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 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 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 WARNING
25. ft lbs cranking solenoid on engines so equipped with torque wrench See Figure 11 46 Leave screws slightly loose at this time 11 15 Section 11 Reassembly 3 Install wiring connector to 1 cylinder side baffle Install Blower Housing with two hex flange screws See Figure 11 48 1 Install the blower housing on the engine See Figure 11 50 Figure 11 48 Installing Wiring Connector Figure 11 50 Installing Blower Housing Install Electric Starter Motor 1 Install electric starter motor by inserting thru bolts 2 Secure the blower housing to crankcase The two into flange of lower crankcase See Figure 11 49 shorter screws are installed at the top positions and the four longer screws go in the middle and bottom positions Leave screws slightly loose to shift housing See Figure 11 51 Figure 11 49 Installing Electric Starter Motor 2 Tighten bottom bolt first then the top bolt Figure 11 51 Securing Blower Housing Screws 3 Install hex flange nuts in recesses at top front of blower housing 11 16 Install Grass Screen or Retractable Starter 1 If the engine does not have a retractable starter snap grass screen in place or attach to flywheel fan with appropriate hardware Position the retractable starter with handle in same position as removed Install the five retaining screws but leave loose until step 4 is complete Pull the starter handle out until the pawls engage in the drive c
26. level NOTE Do not overfill the battery Poor performance or early failure due to loss of electrolyte will result 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 8 3 Section 8 Electrical System and Components 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 will need a DC voltmeter Perform the following steps see Figure 8 2 1 Connectthe voltmeter across the battery terminals 2 Crankthe engine If the battery drops below 9 volts while cranking the battery is discharged or faulty Electronic CD Ignition Systems Operation of CD Ignition Systems This system consists of the following components DC Voitmeter Battery Figure 8 2 Battery Voltage Test Amagnet assembly which is permanently affixed to the flywheel Two electronic capacitive discharge ignition modules which mount on the engine crankcase Figure 8 3 Akill switch or key switch which grounds the modules to stop the engine Two spark plugs 8 4 Section 8 Electrical System and Components Kill Switch o
27. oil drain plugs A drain plug is located on either side of the crankcase one is below the oil filter and the other is below the starter See Figure 6 4 3 Allow all oil to drain and then reinstall the drain plug Torque to 13 6 N m 10 ft Ib 4 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 5 Reinstall the oil fill cap Section 6 Lubrication System Figure 6 5 Removing Oil Filter 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 oil filter as follows see Figures 6 5 and 6 6 1 Clean areas around drain plug oil filter dipstick and oil fill cap 2 Remove one of the oil drain plugs A drain plug is located on either side of the crankcase one is below the oil filter the other is below the starter 3 Allow all the oil to drain and then reinstall the drain plug Tighten 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 Puta drop of oil on your fi
28. oil of proper type up to the full mark Reinstall oil fill cap and dipstick F Mark Operating Range Figure 6 3 Oil Level Marks on Dipstick 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 Oil Change Overhead Valve For New Engines change oil after the first 5 hours of operation then every 100 hours of operation thereafter 6 2 For Overhauled Engines or those rebuilt with a new Short Block or Miniblock use 10W 30 weight Kohler Command service class SG or SH for the first 5 hours of operation Change the oil after this initial run in period Refill with service class SG or SH oil of viscosity specified under Oil Types When changing oil drain oil while the engine is still warm from operation The oil will flow more freely and carry away more impurities Tilt the engine slightly toward the oil drain and allow ample time for complete drainage After draining reinstall drain plug Fill with proper oil to the F mark on the dipstick Always check the level with the dipstick before adding more oil Make sure engine is level when filling and checking oil Figure 6 4 Location of Oil Drain on Oii Filter Side Change the oil as follows 1 Clean the areas around the drain plug dipstick and oil fill cap 2 Remove one of the
29. removed or the paper element or precleaner are serviced check the following Air Cleaner Element Cover Grommet and Seal Make sure element cover is not bent or damaged Make sure the wing nut grommet and seals are in place to ensure the element is sealed against leakage Be sure the grommet aligns with the hole in the base If the element cover is installed backward the hole in the base will not be sealed Air Cleaner Base Make sure the base is secured tightly to carburetor elbow and not cracked or damaged 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 If the base plate has to be removed proceed as follows 1 Remove air cleaner components from the base as described under Paper Element Service see page 4 2 2 Remove the hex flange screws securing the bracket top tank version and base Figure 4 7 3 Remove the base and gasket 4 Reverse procedure to reassemble components Tighten screws to 9 9 N m 88 in Ib torque Figure 4 7 Removing Base on Standard Type Air Cleaner Air Intake Cooling System To ensure proper cooling make sure the grass screen cooling fins and other external surfaces of the engine are kept clean at all times Every 100 hours of operation more often under extremely dusty or dirty conditions re
30. single cylinder camshaft pin Part No 47 380 09 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 10 3 Section 10 Inspection and Reconditioning Cylinder Bore Inspection and Service Check the cylinder bores for scoring Unburned fuel can result in 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 either of the cylinder bores is badly scored excessively worn tapered or out of round replacement of the upper crankcase half will be necessary Non replaceable liners are included in the upper crankcase These are not to be rebored Oversize pistons and rings are not available for these engines 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 foll
31. start switch is released the starter solenoid is deactivated the drive lever moves back and the drive pinion moves out of mesh with the ring gear into the retracted position End Frame Rear Stop Collar SM Rear Pusnng Front Stop Collar Front Bushing Figure 8 18 Exploded View of Solenoid Shift Starter R SS EN D cover Insulator ZS Spring thru Bolt Brush Holder 8 16 Starter Removal and Reinstallation Refer to the engine disassembly and reassembly sections later in this manual for starter removal and installation procedures Starter Disassembly 1 Disconnect the 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 brush springs from the brush spring holder Insulator Figure 8 19 Removing the Insulator 6 Remove the armature from the frame 7 Remove the drive lever and armature from the drive end cap Armature Figure 8 20 Removing the Armature and Drive Lever Section 8 Electrical System and Components Front Stop Collar Retainer Rear Stop Collar Figure 8 21 Stop Collars and Retainer 8 The stop collar consists of two pieces The rear stop collar is held in place by being snapped over a retainer The retainer is held in place by a groove in the armature shaft The front stop collar rests against the
32. stop the engine On vehicular applications lawn tractors mowers etc the pressure switch can only be used to activate a low oil warning light 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 6 4 Installation The Oil Sentry pressure switch is installed in the oil filter adapter 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 new switch follow these steps 1 Apply pipe sealant with teflon to the threads of the switch 2 Hand start the switch into the tapped hole in the oil filter adapter See Figure 6 6 3 Torque the switch to a maximum 3 4 N m 30 in Ib Do not overtighten or you will crack the adapter 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 psig pressure applied to the switch the tester should indicate continuity switch closed 2 Gradually increase the pressure to the switch As pressure increases through the range of 3 0 5 0 psig the tester should indicate a change to no continuity switch open The switch should remain open as the pressure is increased to 90 psig maximum 3 Gradually decrease the pressure through the range of 3 0 5
33. the manifold studs to secure the carburetor Torque the nuts to 9 9 N m 88 in Ibs Feed breather hose through control bracket and carefully attach lower end to breather cover Be sure flanges overlap cover hole for a positive seal Reattach the upper end to flange on the air intake elbow and secure it with the hose clamp Connect the fuel line to carburetor and secure with a hose clamp See Figure 11 53 Insert a small nail through hole in end of governor shaft Reset governor by rotating cross shaft counterclockwise and pushing governor lever toward control bracket then tightening the screw and nut 11 17 Section 11 Reassembly Bushing Governor ri Spring t Bushing 4 Bushing Linkage Spring __ Throttle Link PivotLever Screw TS Clamp xc Control Lever Spacer Figure 11 54 Standard Throttle Control Detail Install Muffler 1 Install new exhaust gaskets on both ports 2 Install muffler on studs and secure with four nuts See Figure 11 55 Figure 11 55 Installing Exhaust Gasket and Muffler f r Governor Link Screw r Governor Lever Nut y Location B 4 Choke Cable Fastner amp Clamp Choke Location A L7 Screw amp Clamp x NK gt Spacer o WS Control Wave Washer W N Bracket N 7 Governor Pivot Lever No NON N Sd Spacer Seti Ne NM Spacer iN Screw Contro Link
34. 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 Connect tester quick disconnect to the adapter hose while firmly holding the engine at TDC Note the gauge reading and listen for escaping air at the carburetor intake exhaust outlet and crankcase breather Check your test results against the table below Leakdown Test Results Air escaping from crankcase breather ssss Air escaping from exhaust system sssssseeee Air escaping from carburetor ssnsaneoneseeeseeerisenrreere nnne Gauge reading below 25 leakage s Gauge reading 25 50 leakage Gauge reading above 50 leakage s sesnnnsrarerrererersrere 3 4 atipi Defective rings or worn cylinder walls AETS Defective exhaust valve ais Defective intake valve Vitus Piston rings and cylinder in good condition Engine is still usable but there is some wear present Customer should start planning for overhaul or replacement OREA Rings and or cylinder have considerable wear Engine should be reconditioned or replaced TH16 amp TH18 Section 4 Air Cleaner and Air Intake System Air Cleaners General These engines are equipped with a replaceable high density paper air cleaner elemen
35. 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 Kohler Part No 25 761 05 is a relatively simple inexpensive leakdown tester for small engines The tester includes a quick disconnect for attaching the adapter hose and a 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 crankshaft until piston of cylinder being tested is at top dead center of compression stroke You will need to hold the engine in this position while testing The holding tool supplied with the tester can be used if the PTO end of the crankshaft is accessible Slide the holding tool onto the crankshaft and adjust the set screw to fit in the key slot Install a 3 8 breaker bar into the square hole of the holding tool so it is perpendicular to both the holding too and crankshaft PTO If the flywheel end is more accessible you can use a breaker bar and socket on the flywheel nut screw to hold it in position You may need an assistant to hold the breaker bar during testing If the engine is mounted in a piece of equipment you may be able 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
36. 0 Oil Pump Outer Parts Figure 10 21 Cover With Bearing Installed 4 If further disassembly is needed press the inner 5 Install new oil seal and O Ring when ball bearing out of the cover and install a new one reassembling the pump in its place See Figure 10 21 10 13 TH16 amp TH18 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 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 component subassembly work has been completed The sequence may vary to accommodate options or special equipment Detailed procedures can be found in the subsections following this sequence Install valve train Install connecting rods with pistons and rings Install crankshaft Instail oil pick up screen Install oil pressure relief install oil pump Assemble crankcase halves Stator wire routing Install crankcase breather 10 Install oil filter adapter 11 Install Oil Sentry Switch 12
37. 1 11 Section 11 Reassembly 9 Adjust timing belt tension cold engine by applying 3 4 4 5 N m 30 40 in Ibs torque in counterclockwise direction Tighten idler assembly screws to 7 3 N m 65 in Ibs starting with the lower screw See Figures 11 32 and 11 35 Figure 11 35 Adjusting Timing Belt Tension 10 Reinstall the stator and torque the mounting screws to 4 0 N m 35 in Ibs 11 Check to make sure all wiring is routed away from the timing belt to prevent cutting wires Install Flywheel a 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 flywheel hub are clean dry and completely free of lubricants The presence of lubricants can cause the flywheel to be overstressed and damaged when the retaining screw is torqued to specifications Cold Engine NOTE Always use a flywheel strap wrench or holding tool to hold the flywheel when tightening the flywheel fastener Do not use any type of bar or wedge to hold the flywheel as component damage and personal injury could result 1 Ins
38. 30 in Gap Figure 8 1 Servicing Spark Plug 4 Reinstall the spark plug into the cylinder head and tighten to 24 4 29 8 N m 18 22 ft Ib 8 1 Section 8 Electrical System and Components 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 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 overrich carburetion weak ignition or poor compression 2 EY nas D uu 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 Section 8 Electrical System and Components Wet Fouled A wet plug is caused by excess fuel or oil in the combustion chamber Excess fuel could be caused by a carburetor problem or operating the engine with too much choke Oil in the combustion chamber is usually caused by a breather problem worn piston rings or valve guides Overheated Chalky white deposits indicate very high combustion te
39. Note locating pin in crankcase to align bearing Replacement sleeve bearings are available in standard and 0 25 mm 0 010 in undersize If PTO end ball bearing turns easily and noiselessly reuse Press replacement bearing on if needed Install snap ring on TH18 See Figure 10 4 If the sleeve bearing journal is worn or damaged it can be ground 0 25 mm 0 010 in undersize and fitted with an undersize bearing When grinding a crankshaft grinding stone deposits can get caught in oil passages which could cause severe engine damage Removing the plug each time the crankshaft is ground provides easy access for cleaning any grinding deposits that may collect in the oil passages See Figure 10 4 Press ball bearing flush to shoulder Press cup plug to bottom of counterbore Install Snap Ring on TH18 Figure 10 4 Cup plug Ball Bearing Installation Detail Use the following procedures to remove and replace the plug 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 5 Self Tapping Screw Flat Washer Figure 10 5 Removing Crankpin Plug 3 Tighten the self tapping screw until it draws the plug out of the crankshaft Procedure to Install New Plug 1 Use a
40. ankshaft Assembly 2 With the rod journal up carefully place crankshaft in upper crankcase half NOTE The snap ring on the ball bearing must rest in the groove in the crankcase aligning hole in the front main bearing must be over the roll pin and the oil hole must align with groove in crankshaft journal 3 Pull the connecting rods toward the crankshaft and fit the bearing surfaces to the rod journal on the crankshaft Lubricate the journal and rod caps with engine oil and reassemble the caps to the appropriate rods The match marks should be to the outside 4 Install connecting rod bolts and torque in increments to final torque of 11 3 N m 100 in Ibs See Figure 11 4 11 2 Section 11 Reassembly Figure 11 4 Torquing Conne 5 Turn crankshaft to see that it turns freely 6 Grease lips of front oil seal and use a seal driver to install seal to depth shown in Figure 11 5 6 0 mm 0 2362 in h PEN N WN NN Oil Seal Apply Oil Before Assembly Roll Pin Press to Bottom Apply Oil Before Assembly Install Oil Pick up Screen 1 Install the oil pick up filtering screen inside the lower crankcase half See Figure 11 6 Figure 11 6 Installing Oil Pick up Screen 2 Secure the screen with two torx head screws Torque these to 4 0 N m 35 in Ibs Install Oil Pressure Relief 1 If they were removed install the relief va
41. arburetor When the solenoid is loosened and removed gas will leak out of the carburetor Have a container ready to catch the fuel 2 Attach a wire between the solenoid ground lead terminal and a battery ground with alligator clips A CAUTION Do this test away from any fuel vapors to prevent an accident 3 Insert a bare 1 4 male spade terminal into the terminal end of the power lead Touch the exposed terminal to the positive post of the battery 4 If pin retracts the solenoid is good Adjustments General The carburetor is designed to deliver the correct fuel to air mixture to the engine under all operating conditions Fuel mixture settings are set at the factory and are not adjustable NOTE Carburetor speed adjustment should be made only after the engine has warmed up 5 6 Figure 5 4 Fuel Shut off Solenoid Equipped Carburetor Low Idle Speed Adjusting Screw To adjust the carburetor idle speed see Figure 5 5 and follow these steps 1 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 Section 5 Fuel System and Governor Figure 5 5 Carburetor Adjustment 2 Place the th
42. at this time Lubricate the seal with engine oil and press into the 2 side crankcase to the depth shown in Figure 10 15 1 5 mm 0 0591 in Governor Cross Shaft Oil Seal Figure 10 15 Governor Cross Shaft Oil Seal 10 11 Section 10 Inspection and Reconditioning The oil seal for the oil pump is pressed into the pump cover to a depth of 1 5 mm as shown in Figure 10 16 1 5 mm 0 0591 in Cl CIE Kail RON L RAR Figure 10 16 Cross Sectioned View of Oil Pump Showing Oil Seal Depth Oil Pump Reconditioning The oil pump is driven by the timing belt on this engine The flywheel must be removed to gain access to the oil pump Refer to Disassembly Section 9 for details A service replacement oil pump assembly is available To recondition the existing oil pump proceed as follows 1 Use the flywheel holding tool to hold sprocket Then remove retaining screw washers and sprocket A small gear puller may be required to free the sprocket from the shaft See Figures 10 17 and 10 18 Figure 10 17 Using Holding Tool to Remove Sprocket 10 12 Figure 10 18 Oil Pump Sprocket and Retainer 2 Remove the three screws holding the oil pump cover to the lower crankcase half See Figure 10 19 Figure 10 19 Oil Pump Cover Removal 3 Remove the cover wear plate and the outer rotor and shaft See Figure 10 20 Section 10 Inspection and Reconditioning Figure 10 2
43. attempt to adjust by bending the tab replace float with kit if level is wrong Turn Carburetor Upside Down Figure 5 6 Proper Float Level Pull the float hinge pin and remove the float with float needle valve attached to inspect these parts and needle seat If dirty blow out with compressed air Replace float components as needed with kit Use new bowl gaskets reinstall bowl tighten bowl retaining screw or solenoid if used to 5 1 6 2 N m 45 55 in Ib Reinstall carburetor on engine reconnect fuel line control linkages and air intake components Retest operation 5 7 Section 5 Fuel System and Governor Disassembly Disassemble carburetor as follows after removal from engine See Figure 5 7 1 Remove the fuel bowl retaining screw or solenoid assembly then remove bowl and bowl gasket Pull the float hinge pin and remove the float with inlet needle attached Remove the vent plug from the column on solenoid equipped carburetors Remove the setscrews holding the throttle plate to the throttle shaft and pull the throttle shaft from carburetor body Figure 5 7 Carburetor Exploded View Remove the setscrews securing the choke plate to the choke shaft assembly and pull the choke shaft assembly out of the carburetor body Disassemble self relieving parts from shaft as needed Remove the three screws holding the passage cover to the body and remove the cov
44. bushing and disconnect the governor link from the pivot lever Mark the hole position of the governor spring in the governor lever and governor pivot lever Remove the spring Remove Retractable Starter or Grass Screen 1 Figure 9 9 Remove Retractable Starter On engines so equipped remove the retractable starter from blower housing by removing the five mounting screws Note the position of the starter handle to reinstall it later See Figure 9 9 2 Onengines with a grass screen either unsnap the screen or remove the screws holding it to the flywheel fan Remove Blower Housing 1 Figure 9 10 Removing Blower Housing If the rectifier regulator is mounted to the blower housing remove the left screw to disconnect the ground lead Remove the blower housing by removing the six hex flange screws and two hex flange nuts in recesses at top front of housing Make note of location of the two shorter screws See Figure 9 10 Section 9 Disassembly Remove Electric Starter 1 Ifthe engine is equipped with a cranking solenoid disconnect all leads remove the two hex flange mounting screws and remove the solenoid See Figure 9 11 Figure 9 11 Removing Solenoid 2 The starter thru bolts are also the mounting bolts Tape the end caps to the frame to prevent them from separating when the bolts are loosened 3 Remove the top 3 8 mounting screw as shown in Figure 9 12 Figure 9 12 Removin
45. ck and forth checking for clearance between the magnet and ignition modules Make sure the magnet does not strike the modules Check the gap with a feeler gauge and readjust if necessary Final Air Gap 0 20 0 30 mm 0 008 0 012 in Connect the kill leads to the terminals Modules Set Valve Clearance ale 2 Figure 11 39 Adjusting Valve Clearance 1 Turn flywheel clockwise to TDC on the 1 side Loosen locking nut and screw and insert feeler gauge blade Clearance should be 0 013 0 064 mm 0 0005 0 0025 in for the intake valve and 0 076 0 127 mm 0 0030 0 0050 in for exhaust valve Adjust screw in or out until it is the correct clearance then tighten locking nut See Figure 11 39 Shown 3 Turn flywheel clockwise 270 until 2 cylinder is at TDC Repeat clearance checks and adjustment procedure from step 2 on 2 side Set this side to same clearance 0 013 0 064 mm 0 0005 0 0025 in for the intake valve and 0 076 0 127 mm 0 0030 0 0050 in for the exhaust valve 11 13 Section 11 Reassembly Install 1 Side Valve Cover Install 2 Side Valve Cover 1 Install new cover gasket on 1 valve chamber 1 Install new cover gasket on 2 valve chamber 2 Install valve cover and insert the four fasteners 2 Install valve cover and insert the six fasteners Note that the lifting strap is usually installed in the lower front position See Figure 11 40 NOTE On engines with top mounted fu
46. e speed 3200 to 3750 RPM Openthe clamp and note the water level in the tube The level in the engine side should be a minimum of 30 cm 12 in above the level in the open side If the level in the engine side is the same as the open side 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 below Close the shut off clamp before stopping the engine No Crankcase Vacuum Pressure in Crankcase Crankcase breather clogged or inoperative Seals and or gaskets leaking Loose or improperly torqued fasteners Piston blowby or leaky valves Confirm by inspecting components Restricted exhaust Compression Test Disassemble breather clean parts thoroughly 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 Replace piston and or rings Recondition replace valves Recondition valve guides See Section 10 Repair replace restricted muffler exhaust system 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 alternate use the leakdown test described on the next page 3 3 Section 3 Troubleshooting Cylinder Leakdown Test A cylinder leakdown test can be a
47. e the spring is disengaged from the starter housing 6 Hold the pulley into 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 7 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 Figure 7 7 Removing Pulley from Housing 7 3 Section 7 Retractable Starter 8 Note the position of the spring and keeper Reassembly assembly in the pulley See Figure 7 8 1 Make sure the spring is well lubricated with grease Place the spring and keeper assembly Remove the spring and keeper assembly from the inside the pulley with spring towards pulley See pulley as a package Figure 7 9 a WARNING Spring Under Tension 2 Install the pulley with spring and keeper assembly Do not remove the spring from the keeper Severe into the starter housing See Figure 7 9 personal injury could result from the sudden uncoiling of the spring Make sure the pulley is fully seated against the starter housing Do not wind the pulley and recoil spring at this time Figure 7 8 Position of Spring and Keeper in Pulley Figure 7 9 Installing Pulley and Spring into Inspection and Ser
48. ectifier 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 stator 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 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 Stator
49. el ring gear may clash resulting in damage to the starter Troubleshooting Guide Starting Difficulties Possible Fault NOTE f 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 from United Technologies UT 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 2 Replace wires in poor condition and with frayed or broken insulation 1 Bypass the switch or solenoid with a jumper wire If starter cranks normally replace the faulty components Check the specific gravity of battery If low recharge or replace battery as necessary Battery 1 2 Battery too small must be at least 250 cold cranking amps Starter Energizes But Turns Slowly Transmission or Engine 1 Check for excessively dirty or worn brushes and commutator Clean using a coar
50. el tanks the top three are fuel adapter studs See Figure NOTE On engines with top mounted fuel tanks the 11 42 top two are fuel tank mounting studs See Figure 11 42 ae i N Figure 11 42 Stud Location on Top Mounted s p Tank 2 Side Figure 11 40 Installing Valve Cover 1 Side 3 Torque the fasteners to 5 6 N m 50 in Ibs see 3 Torque the fasteners to 5 6 N m 50 in Ibs in Figure 11 43 in the sequence shown in Figure the sequence shown in Figure 11 41 11 44 NE Figure 11 43 Installing Valve Cover 42 Side Figure 11 41 Valve Cover Tightening Sequence 1 Side 11 14 Section 11 Reassembly Figure 11 44 Valve Cover Tightening Sequence Figure 11 46 Torque Spark Plugs 82 Side 3 Leave spark plug leads disconnected until later Install Dipstick 1 Reinstall dipstick in tube on PTO end See figure Install Cylinder Side Baffles 11 45 1 Install the 2 cylinder side baffle and secure with one hex flange screw Leave screw slightly loose at this time See Figure 11 47 Figure 11 45 Installing Dipstick in Tube Install Spark Plugs Figure 11 47 Installing 2 Side Baffle 1 Install new spark plugs after setting gap at 0 76 mm 030 in 2 Install the 1 cylinder side baffle and secure with two hex flange screws which also mounts the 2 Tighten plugs to 24 4 29 8 N m 18 22
51. er D Governor Spring Z T Nut Location B Governor Link Choke Cable Fastener amp Clamp Location A LL Screw amp Clamp NG M ON Choke Lever Ne RON Spacer Nw Control N E Bracket Wave Washer oO d MN NN Governor Pivot Lever CN N N NS QN Spacer N d Spacer NON Screw Control Link Figure 9 8 Standard Throttle Control Detail 9 3 Section 9 Disassembly 10 11 9 4 Disconnect the fuel line from the carburetor by using a needle nose pliers to loosen the hose clamp Remove the two hex flange nuts from the carburetor mounting studs On engines without a top tank thread the carburetor nuts flanges facing onto the stud protruding from the top of the crankcase Jam them together and then turn the lower one counterclockwise to remove the stud Slide the intake elbow carburetor and spacer off the mounting studs on the intake manifold Lift the carburetor and control bracket assembly and disconnect the leads from the fuel shut off solenoid Remove the carburetor control bracket governor lever and attached linkages as an assembly If further service of the components is necessary the assembly can be broken down following steps 8 11 Unsnap the linkage bushing and disconnect the throttle link and linkage spring from the pivot lever See Figure 9 8 Disconnect choke link from carburetor and choke lever Unsnap the
52. er gasket Remove the slow speed adjusting needle and spring Except for the slow jet nozzle main jet and emulsion tubes which are considered non serviceable the carburetor is now completely disassembled and ready for thorough inspection and cleaning Cover Retaining Screw Passage Cover Cover Gasket Carburetor Body Self Relieving Choke Choke Plate Setscrew Plates 4 Bowl Retaining Screw Gasket Shut Off Solenoid Assembly Bowl Retaining Screw Fuel Bowl Float Kit Fuel Bowl Gasket Main Jet Throttle Shaft Lever mom boah Throttle Plate Spring Idle Speed Screw Idle Speed Adjusting 5 8 Inspection Repair To clean vent ports seats etc use a good commercially available carburetor solvent such as Gumout and clean dry compressed air to blow out internal channels and port Use a suitable shop rag to prevent debris from hitting someone Carefully inspect all components and replace those that are worn or damaged Inspect the carburetor body for cracks holes and other wear or damage e Inspect the float for cracks holes and missing or damaged float tabs Check the float hinge and shaft for wear or damage nspect the fuel inlet needle and seat for wear or damage The choke plate is spring loaded Check to make sure it moves freely on the shaft Always use new gaskets when servicing or reinstalling carburetors Repair kits are available which include new gaske
53. er installing the new compression top and middle rings on piston check piston to ring side clearance Top ring side clearance is 0 040 0 085 mm 0 0016 0 0033 in for TH16 and TH18 Middle ring side clearance is 0 030 0 080 mm 0 0012 0 0031 in for TH16 and 0 030 0 076 mm 0 0012 0 0030 in for TH18 If side clearance is greater than specified a new piston must be used Refer to Figure 10 10 Piston Ring Top Compression Ring Center Compression Ring Figure 10 10 Measuring Piston Ring Side SE Ring Clearance Three Piece Install New Piston Rings s Figure 10 12 Piston Ring Installation To install piston rings proceed as follows 1 Oil Control Ring Bottom Groove Install the expander and then the rails Make sure the ends of expander are not overlapped 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 2 rings see Figure 10 11 Install the bottom oil control ring first and the top compression ring last Refer to Figure 10 12 Compression Ring Center Groove Install the center ring using a piston ring installation tool Make sure the pip mark is up 3 Compression Ring Top Groove Install the top ring using a piston ring installation tool Figure 10 11 Installing Piston Rings with Expander 10 10 Connecting Rods Offset Stepped Cap Connecting Rods
54. eration of fuel pump a Remove the fuel line from the inlet fitting of carburetor b Crank the engine several times and observe flow If fuel does not flow from the line check for clogged fuel line If the fuel line is unobstructed the fuel pump is faulty and must be replaced 5 2 Section 5 Fuel System and Governor Fuel Pump General Most engines are equipped with a mechanical fuel pump The pumping action is created by a lobe on the 1 side camshaft 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 Two check valves prevent fuel from going backward through the pump Performance Fuel pump outlet pressure should not exceed 13 79 kPa 2 psi to avoid overriding the float system in the carburetor Replacing the Fuel Pump Replacement valve cover fuel pumps are available through your source of supply To replace the valve cover fuel pump assembly follow these steps 1 Disconnect the fuel lines from the inlet and outlet fittings Figure 5 1 Removing 1 Side Valve Cover Fuel Pump Assembly 2 Remove the four hex flange screws and valve cover fuel pump 3 Install a new valve cover fuel pump using the hex flange screws 4 Tighten the hex flange screws to 5 6 N m 50 in Ib 5 Connectthe fuel lines to the inlet and outlet fittings Carburetor General Engines
55. ernor Bushing to Camshaft Running Cleararce 5 itinere entren aaae Load dn 0 045 0 160 mm 0 0018 0 0063 in Governor Bushing I D EE 32 020 32 080 mm 1 2606 1 2630 in Max Wear Limit teen rni AER Ee eases 32 09 mm 1 2634 in Ignition Spark Plug Type Champion or Equivalent ssss RC12YC Spark Pl g Gap eret ee irte teret iens 0 76 mm 0 030 in Spark Plug Torque eene uio te e rire ect sd Ee ANEN 24 4 29 8 N m 18 22 ft Ib Ignition Module Air Gap cecceecceecceeeeeneeeceeeeseeeeeeeeeseesseeeveneeesaaeeas 0 20 0 30 mm 0 008 0 012 in Ignition Module Fastener Torque E 4 0 6 2 N m 35 55 in Ib Muffler Muffler Retaining Nuts Torque ssssessssseeessereererrererrerrarsririserrnssrrnnen 24 4 N m 216 in Ib Oil Filter Qil Filter Torgus geegent ge dE a regalo 5 6 9 0 N m 50 80 in Ib Oil Filter Nipple Torque ssseeeeennneem een emnes 40 7 N m 30 ft Ib Oil Sentry Pressure Switch esses 3 4 Nm 30 in Ib Piston Piston Rings and Piston Pin Piston Pin Bore to Piston Pin Select EI 0 006 0 016 mm 0 0002 0 0007 in Piston Pin Bore LD NOW cst n Ut a ERE cer eei SS co E EE IE 17 006 17 012 mm 0 6695 0 6698 in Max Wear Limit ere eire Reeder bh 17 025 mm 0 6703 in Piston Pin O D NOW iustis ute es o end a 16 996 17 000 mm 0 6691 0 6693 in Max Wear Lirik eere t rre tede ea een reda inne 16 995 mm 0 6691 in Top Compressi
56. 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 Assemble the inner halves with the larger cavity around the spring retainer see Figure 8 14 Slide the collar over them and thread the center screw in until resistance is felt 5 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 6 Reinstall the dust cover 8 14 Section 8 Electrical System and Components UT Starter Disassembly 1 Remove the dust cover retainer ring spring retainer anti drift spring dust cover spacer and drive pinion Refer to UT Starter Drive Service starting on page 8 13 2 Remove the thru bolts 3 Remove the commutator end cap with brushes and brush springs 4 Remove the drive end cap 5 Remove the armature and thrust washer from inside the starter frame UT Brush Replacement 1 Remove the brush springs from the pockets in brush holder See Figure 8 15 Brush Springs Self Tapping Screw Negative Brush Self Tapping Screw Stud Terminal With Positive Brushes Figure 8 15 Commutator End Cap with Brushes 2 Remove the self tapping screws negative brushes and plastic brush holder 3
57. fins grass screen and other external surfaces Dirt or debris on these areas are causes of overheating e Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or improperly assembled breather worn or damaged seals and gaskets or loose or improperly torqued fasteners e Check the air cleaner cover and base for damage or indications of improper fit and seal e 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 underserviced e Check the carburetor throat for dirt Dirt in the throat is further indication that the air cleaner is not functioning properly e Checkthe 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 interval 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 dra
58. g Crank the engine and observe the tester spark gap Repeat the If the tester shows spark but the engine misses or procedure on the other cylinder Remember to won t run on that cylinder try a new spark plug reconnect the first spark plug lead If neither side is firing check for shorted kill lead or faulty ignition switch Ground Clip Post Terminal 8 6 Section 8 Electrical System and Components Battery Charging Systems General These engines are equipped with either a 15 amp or 25 amp regulated battery charging system See Figure 8 5 for the 15 amp system with panel diagram and Figure 8 6 for the 15 25 amp system without panel diagram NOTE Observe the following guidelines to avoid damage to the electrical system and components Make sure the battery polarity is correct A negative ground system is used e Disconnect the rectifier regulator leads and or wiring harness plug before doing electric welding on the equipment powered by the engine Also disconnect other electrical accessories in common ground with the engine Prevent the stator AC leads from touching or shorting while the engine is running This could damage the stator 28 518 01 Lower Blower Violet Red Blue Red E Ground round Lead Housing Screw Wires Wires R Rectifier Pax h H S ECH Oil Sentry Yellow M Magneto Q ntry Oil Pressure Wire x Panel Light D Switch 7 Starter White Wires Red Wire A Accessory Fro
59. g Starting Motor 4 Loosen the bottom 3 8 mounting screw just enough to remove the starting motor Do not completely remove the mounting screw from starter Remove Side Baffles 1 Remove the single screw holding the side baffle to the 2 cylinder and remove the baffle See Figure 9 13 Figure 9 13 Removing 2 Side Baffle 2 To remove the 1 side baffle loosen the two screws holding the wire connector and slide the connector off 3 Remove the side baffle from the 1 cylinder See Figure 9 14 gure 9 14 Removing 1 Side Baffle Remove Ignition Modules 1 Turn the flywheel magnet away from the ignition modules 2 Disconnect the white kill leads 9 5 Section 9 Disassembly 3 Remove the two hex flange mounting screws from each module and remove both modules See Figure 9 15 Figure 9 15 Removing Ignition Modules 1 Side Shown Remove Flywheel NOTE Always use a flywheel strap wrench or holding tool to hold the flywheel when loosening or tightening the flywheel screw Do not use any type of bar or wedge to hold the flywheel Use of such tools could cause the flywheel to become cracked or damaged 1 Hold flywheel with a strap wrench or holding tool refer to Section 2 Turn flywheel retaining screw 13 mm socket counterclockwise to remove screw and washer Engines with retractable starters will also have the drive cup retained with the flywheel screw See Figure 9 16 Figure 9 16
60. g engine downtime Flywheel Strap Wrench eene enne nennen NU 10357 Flywheel Puller Kit AAA NU 3226 Water Manometer AA 25 761 02 Cylinder Leakdown Tester 25 761 05 Ignition System Tester nne 24 455 02 Camshaft Timing Tool Set sse eene 28 761 01 Starter Snap Ring Kin 25 761 18 Valve Blocking Tools and Engine Stand A 28 761 02 Contact your Kohler Distributor for price and availability Ignition System Tester Use Kohler Part No 24 455 02 to test the CD ignition modules on the OHC engines Cylinder Leakdown Tester Kohler Part No 25 761 05 Cylinder Leakdown Tester is a valuable alternate to a compression test 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 on page 3 4 of this manual Special Tools You Can Make Figure 2 1 Flywheel Holding Tool Flywheel Holding Tool Flywheel removal and reinstallation becomes a snap using a handy holding tool you can make out of a piece of an old junk flywheel ring gear as shown in Figure 2 1 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 crankcase so that the tool teeth engage the ring gear teeth on the flywheel The bosses will lock the tool and flywheel in
61. g is acceptable up to 40 F Synthetic oils will provide better starting in extreme cold below 10 F NOTE Using other than service class SG or SH oil or extending oil change intervals longer than recommended can cause engine damage A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 6 1 Figure 6 1 Oil Container Logo The top position of the symbol shows service class such as API SERVICE CLASS SG The symbol may show additional categories such as SH 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 car engines 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 cool so the oil has had time to drain into sump 2 Clean the area around the dipstick before removing it This will help to keep dirt grass clippings etc out of the engine 6 1 Section 6 Lubrication System 3 Remove the dipstick wipe oil off Reinsert the dipstick into the tube until fully seated See Figure 6 2 Figure 6 2 Location of Dipstick and Starter Side 4 Remove dipstick and check oil level The level should be between the F and L marks If low add
62. gure 8 17 The small notch in the edge of the end cap adjacent to the match mark will engage a small tang inside the end of the starter frame Match Marks Figure 8 17 UT Starter Assembly Match Marks 4 Install the brush holder tool to keep the brushes in the pockets of the commutator end cap 5 Align the terminal stud on the commutator end cap with the long scribe mark on the starter frame Hold the drive end and commutator end caps firmly to the starter frame Remove the brush holder tool Magnet Switch Drive Lever Drive Housing Retainer 6 Install the thru bolts and tighten securely 7 Lubricate the drive shaft with Kohler electric starter drive lubricant Install the drive pinion dust Cover spacer anti drift spring spring retainer retaining ring and dust cover Refer to UT Starter Drive Service on page 8 13 Solenoid Shift Electric Starter This subsection covers the solenoid shift electric starter Much of the information in the preceding subsection relates to this starter therefore it is not repeated here Please use the exploded view Figure 8 18 for reference during the disassembly and assembly procedure Operation 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 When the engine starts and the
63. he crimped portion to the post 6 Replace the brush holder in the frame and place the brushes in the brush holder Reinstall the Springs Trimmed Edge Spare Brush Retainer Rear Stop Collar Figure 8 29 Installing Retainer Starter Service Clean drive lever and armature shaft then apply Kohler electric starter drive lubricant or equivalent to lever and shaft Starter Reassembly 1 Insert the rear stop collar on the armature shaft Figure 8 28 Soldering Brush Clips To Posts 8 19 Section 8 Electrical System and Components Grease Grease Engine Cil Grease K A Q eh Grease Engine Oil Engine Oil Figure 8 30 Lubrication Points Figure 8 31 Tightening the Retainer Figure 8 32 Installing the Stop Collar 2 Install new retainer in the groove on the armature 3 Fitthe front stop collar over the shaft and bring shaft the front and the rear stop collars together over the retainer Using two pairs of pliers apply even NOTE Always use a new retainer Tighten the force to the two collars until they snap over the retainer in the groove to secure retainer and nest into one another 8 20 Section 8 Electrical System and Components Brush Spring Figure 8 33 Installing the Brush Springs 4 Reassemble the remaining components of the starter in reverse order of disassembly 8 21 TH16 amp TH18 Section 9 Disassembly AA Warnine Accidental Starts Before servici
64. hetic oil having 5W 20 or 5W 30 rating is acceptable up to 40 F Synthetic oils will provide better starting in extreme cold below 10 F NOTE Using other than service class SG or SH oil or extending oil change intervals longer than recommended can cause engine damage A logo or symbol on oil containers identifies the API service class and SAE viscosity grade See Figure 1 3 Figure 1 3 Oil Container Logo Refer to Section 6 Lubrication System for detailed procedures on checking the oil changing the oil and changing the oil filter Fuel Recommendations y iN 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 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 recommended Such a container is easier to handle and helps eliminate spillage during refueling Do not use gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting Do not add oi
65. hrottle and choke controls and the high speed stop as necessary Refer to the Fuel System and Governor section FOR SALES AND SERVICE INFORMATION IN U S AND CANADA CALL 1 800 544 2444 FORM NO TP 2480 ISSUED 2 97 REVISED MAILED 3 97 LITHO IN U S A KOHLERENGINES ENGINE DIVISION KOHLER CO KOHLER WISCONSIN 53044
66. ilding TP 2150 for additional information Measurement Guide TP 2159 A and Engine Inspection Data Record TP 2435 are also available use these to record inspection results 10 1 Section 10 Inspection and Reconditioning Camshafts This engine features two overhead camshafts which are belt driven off the crankshaft The camshaft on the 1 side drives the mechanical fuel pump which is part of the 1 side valve cover The 2 side camshaft includes governor components to limit top governed speed Refer to Section 5 for information on governor function Inspection and Service Inspect cam lobes for signs of wear Replace camshaft if itis badly worn If the sprocket is damaged or worn replace it NOTE The same sprocket is used on both camshafts On the 1 camshaft it is mounted with the 1 visible to the front On the 2 camshaft it is reversed so the 2 is visible Crankshaft The crankshaft assembly on this engine includes a sprocket for driving the timing belt a sleeve bearing on the flywheel end and a ball bearing on the PTO end The ball bearing includes a locating snap ring which controls end play of the crankshaft Inspect and or service components as follows Inspection and Service Inspect the teeth of the sprocket Replace the sprocket if the teeth are badly worn chipped or missing Depending on tolerances the sprocket is usually a light press fit on the crankshaft and is keyed to the shaft Install as fol
67. in this series are equipped with fixed jet carburetors Some applications utilize a fuel shut off solenoid which is installed in place of the fuel bowl retaining screw All carburetors feature the self relieving choke components shown in the exploded view on page 5 9 These carburetors include three main circuits which function as follows Float Circuit Fuel level in the bowl is maintained by the float and fuel inlet needle The buoyant force of the float stops fuel flow when the engine is at rest When fuel is being consumed the float will drop and fuel pressure will push the inlet needle away from the seat allowing more fuel to enter the bowl When demand ceases the buoyant force of the float will again overcome the fuel pressure and stop the flow Slow Circuit See Figure 5 2 At low speeds the engines operates only on the slow circuit As a metered amount of air is drawn through the slow air bleed jet fuel is drawn through the main jet and further metered through the slow jet Air and fuel are mixed in the body of the slow jet and exit to the transfer port From the transfer port this air fuel mixture is delivered to the idle progression chamber From the idle progression chamber the air fuel mixture is metered through the idle port passage At low idle when the vacuum signal is weak the air fuel mixture is controlled by the setting of the non accessible idle adjust screw This mixture is then mixed with the main body of air and del
68. inage 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 3 2 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 a water manometer Kohler Part No 25 761 02 is recommended Complete instructions are provided in kit Test the crankcase vacuum with manometer as follows 1 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 Section 3 Troubleshooting Start the engine and run at no load high idl
69. ir intake and cooling areas clean as necessary Section 4 Every 25 Hours Service precleaner element E Replace air cleaner element Section 4 ion H Change engine oil Section 6 ours Remove cooling shrouds and clean cooling areas Section 4 Every Change oil filter Section 6 200 Hours Check spark plug condition and gap Section 8 Annually or Every Have bendix starter drive serviced Section 8 500 Hours 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 Storage If the engine will be out of service for two months or 4 Remove the spark plugs and add one tablespoon more use the following storage procedure of engine oil into each spark plug hole Install plugs and ground spark plug leads do not connect 1 Clean the exterior surfaces of the engine the leads to the plug Crank the engine two or three revolutions 2 Change the oil and oil filter while the engine is still warm from operation See Change Oil and Oil 5 Store the engine in a clean dry place Filter in Section 6 3 The 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
70. iston 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 piston or the pin are worn or damaged a new piston assembly is required Section 10 Inspection and Reconditioning Ring failure is usually indicated by excessive oil Some important points to remember when servicing consumption and blue exhaust smoke When rings fail piston rings oil is allowed to enter the combustion chamber where it is burned along with the fuel High oil consumption can 1 The bore must be deglazed before service ring also occur when the piston ring end gap is incorrect sets are used Use only a ball hone for deglazing because the ring cannot properly conform to the or renewing crosshatch Do not use any other cylinder wall under this condition Oil control is also type Do not allow the balls to contact the lost when ring gaps are not staggered during combustion chamber surfaces installation 2 If the bore is good and the old piston is within When cylinder temperatures get too high lacquer and wear limits and free of score or scuff marks the varnish collect on the pistons causing the rings to old piston may be reused Stick which results in rapid wear 3 Remove old rings and clean up grooves Never Scratches on the rings and pistons are caused by reuse o
71. ivered to the engine As the throttle plate opening increases greater amounts of air fuel mixture are drawn in through the fixed and metered idle progression holes As the throttle plate opens further the vacuum signal becomes great enough so the main circuit begins to work 5 3 Section 5 Fuel System and Governor Main Circuit Figure 5 3 At high loads the engine operates mostly on the main circuit As a metered amount of air is drawn through the main air bleed jet fuel is drawn through the main jet The air and fuel are mixed in the main nozzle and then enter the main body of air flow where further mixing of the fuel and air takes place This mixture is then delivered to the combustion chamber The carburetor has a fixed main circuit There is no adjustment feature present Slow Circuit Slow Air Bleed Jet Slow Jet Transfer Port Idle Progression Chamber Idle Limiter Jet Idle Port Passage Idle Port Idle Progression Holes Bowl Vent Main Circuit ooMgoggnEON Choke Plate Throttle Plate Main Nozzle Emulsion Tube Part of Main Nozzle Main Jet Main Air Bleed Jet Inlet Needle Pin Float Fuel Inlet Figure 5 2 Slow Circuit SONDAN Figure 5 3 Main Circuit 5 4 Section 5 Fuel System and Governor Troubleshooting Carburetor Related Causes Possible Cause Probable Remedy 1 Engine starts hard runs roughly 1 Low idle speed improperly adjusted Adjust the low idle speed or
72. just as follows 1 To increase the sensitivity move the spring closer to the governor lever pivot point 2 To decrease the sensitivity move the spring away from the governor lever pivot point 5 11 TH16 amp TH18 Section 6 Lubrication System General This engine uses a full pressure lubrication system This system delivers oil under pressure to the crankshaft camshafts and connecting rod bearing surfaces A high efficiency gerotor pump is located in the crankcase The oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve in the crankcase limits the maximum pressure of the system Service The two crankcase halves must be separated to service the oil pickup or the pressure relief valve Refer to the appropriate procedures in Section 9 Oil Recommendations Using the proper type and weight of oil in the crankcase is extremely important so is checking oil daily and changing the oil and filter regularly Use high quality detergent oil of API American Petroleum Institute service class SG or SH Select the viscosity based on the air temperature at the time of operation as shown in the following table RECOMMENDED SAE VISCOSITY GRADES ae RES Koh er Winter 10W 30 Lll SW 20 5W 30 Kohler Command LN lap 20 TEMPERATURE RANGE EXPECTED BEFORE NEXT OIL CHANGE Use of synthetic oil having 5W 20 or 5W 30 ratin
73. k Belt Tension in This crankshaft with the keyway over the flywheel key Area Belt Tension Should and the mounting tab toward crankcase Secure Be 30 Lbs the mounting tab to lower stator mounting boss 6 Route timing belt along the left side of crankshaft and oil pump sprockets See Figure 11 32 Timing 7 Route timing belt counterclockwise around remaining sprockets as shown in Figure 11 32 If alc belt h it they should point in th Sprocket elt has arrows on it they should point in the direction of rotation clockwise 8 With idler pulley assembly loose route the belt around the idler sprocket See Figure 11 34 Then install idler assembly as follows Idler Pulley a Start top screw of assembly into crankcase Assembly first Crankshaft 3 Sprocket i b Using 3 8 drive extension on a torque wrench place extension in square slot in plate for leverage Sprocket aL c Apply leverage and install the lower screw Figure 11 32 Timing Belt Detail 3 Insert pins of camshaft timing tool into timing holes in sprockets See Special Tools Section 2 4 Setthe engine to top dead center TDC on the 1 cylinder AT TDC the third tooth counterclockwise from the keyway in crankshaft will be lined up with the point on crankcase See Figure 11 33 Timing Mark EN e EI Figure 11 34 Routing Timing Belt Around Idler Sprocket Figure 11 33 Setting 41 Cylinder at Top Dead Center Cold Engine 1
74. l to gasoline 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 Unleaded gasoline is recommended as it leaves fewer combustion chamber deposits Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 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 gasoline blends up to a maximum of 15 MTBE by volume are approved as a fuel for Kohler engines Other gasoline ether blends are not approved 1 4 Section 1 Safety and General Information Periodic Maintenance A WARNING Accidental Starts Before servicing the engine or equipment always disconnect the spark plug leads to prevent the engine from starting accidentally Ground the leads to prevent sparks that could cause fires Make sure the equipment is in neutral 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 Maintenance Required Fill fuel tank Section 5 Daily or Before Check oil level Section 6 Starting Engine Check air cleaner for dirty loose or damaged parts Section 4 Check a
75. ld rings abrasive material such as carbon dirt or pieces of hard metal 4 Before installing the rings on piston place the top two rings each in turn in its running area in Detonation damage occurs when a portion of the fuel cylinder bore and check end gap see Figure charge ignites spontaneously from heat and pressure 10 9 Top ring end gap is 0 180 0 380 mm shortly after ignition This creates two flame fronts 0 0071 0 0150 in Middle ring end gap is which meet and explode to create extreme hammering 0 180 0 440 mm 0 0071 0 0173 in for TH16 pressures on a specific area of the piston Detonation and 0 180 0 450 mm 0 0071 0 07177 in for generally occurs from using low octane fuels TH18 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 fins improperly seated valve or wrong spark plug Replacement pistons are available in STD bore size only Replacement pistons include new piston ring sets and new piston pins Service replacement piston ring sets are also available separately in STD bore size only Always use new piston rings when installing pistons Never reuse old rings Figure 10 9 Measuring Piston Ring End Gap 10 9 Section 10 Inspection and Reconditioning 5 Aft
76. ll bearing in position It must be removed to remove bearing Discard the oil seal See Figure 9 57 Crankshaft Disassembly 1 The belt drive sprocket has a low interference fit onto the crankshaft If it will not slide off heat the gear slightly with a propane torch until it expands and loosens then remove it with a shop towel or glove See Figure 9 55 Arts T NOTE Snap ring must stay on bearing Figure 9 57 Oil Seal Removed From PTO End Figure 9 55 Belt Drive Sprocket Removed 2 Use a pliers or side cutter to remove the sprocket key from the crankshaft 9 15 Section 9 Disassembly Remove Connecting Rods With Pistons 2 Turn the crankcase upright compress the valve and Rings springs and remove the valve keepers See 1 Pullthe piston assemblies out of both cylinders Figure 9 60 See Figure 9 58 If reusable mark the connecting rods and pistons to match the caps Remove and discard the piston rings a Figure 9 60 Compress Springs to Remove Keepers Figure 9 58 Piston Assemblies Removed 3 Turn crankcase over again for access to valves 4 Use the suction cup end of a valve lapping tool to pull the valves out Refer to Reconditioning Section 10 See Figure 9 61 2 To completely disassemble remove the piston pin retainers and separate pistons from connecting rods Refer to Reconditioning Section 10 Remove Valve Train 1 Install valve blocking tools into the cylinders I
77. lows 1 Install key in keyway for sprocket See Figure 10 1 Figure 10 1 Installing Key For Sprocket 10 2 2 If needed heat sprocket with a 60 watt light bulb or on a hot plate Then slip it into position on crankshaft See Figure 10 2 Figure 10 2 Heat Sprocket Before Installing Inspect the crankshaft keyways If 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 H 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 0 25 mm 0 010 in undersize connecting rods big end must then be used to achieve proper running clearance Measure the crankpin for size taper and out of round NOTE Ifthe crankpin is reground visually check to insure that the fillet blends smoothly with the crankpin surface See Figure 10 3 High Point From Fillet Intersections The Fillet Must Blend Smoothly With The Bearing Minimum Journal Surface This Fillet Area Must Be Completely Smooth Figure 10 3 Crankpin Fillets Section 10 Inspection and Reconditioning Inspect the main bearings and journals Check sleeve bearing surface for scoring grooving or excessive wear To replace slide old bearing off and new in its place
78. lve piston and spring in the lower crankcase half See Figure 11 7 Roll Pin Pressed Flush to d 0 3 Below Surface A r Relief Valve Spring Relief Valve Piston Figure 11 7 Oil Pressure Relief Components Section 11 Reassembly 2 Install the roll pin flush with the surface See Install Oil Pump Figure 11 8 1 Install a new O Ring inside the crankcase See Figure 11 10 D aS Figure 11 8 Installing Oil Pressure Relief Roll Pin 3 Apply pipe sealant with Teflon to the threads and install the oil pressure relief valve pipe plug Torque the plug to 11 3 N m 100 in Ibs See 2 Install new or reconditioned oil pump assembly Figure 11 9 refer to Reconditioning Section 10 Figure 11 10 Installing O Ring Inside Crankcase 3 Secure the oil pump cover to the lower crankcase with the three hex flange screws Tighten these to 7 3 N m 65 in Ibs torque See Figure 11 11 Figure 11 9 Installing Pipe Plug Figure 11 11 Securing Oil Pump Cover to Crankcase Section 11 Reassembly 4 Install the oil pump drive gear on pump shaft See Figure 11 12 Figure 11 12 Oil Pump Drive Gear Parts 5 Secure the drive gear with a wave washer flat washer lock washer and hex flange screw Torque to 9 9 N m 88 in Ibs Assemble Crankcase Halves RTV silicone sealant is used as a gasket between the crankcase halves Refer to the chart on page 2 2 of Special Tools Secti
79. m Light Batter ght 25 099 04 n 48 155 01 Connector Layout Key Switch 48 155 01 Connector Spark Plug ome Plug Cyl 2 Cyl Kill White Baffle To Starter ED Qo4 White pP Solenoid Relay Stud Ground Ge Circuit Violet Stud Black Ignition Carburetor Relay Yetlow 11 Modules Em i mae Fuel Shut off Solenoid Flywheel eee DN Stator Negative y Assembly 1 Battery i be Positive i Starter Solenoid Starter SE Regulator elas i 5 ge Connector g E gt Block Solenoid Shift Starter Assembly Figure 8 5 15 amp Regulated Charging System With Panel 8 7 Section 8 Electrical System and Components 25 155 06 Connector Layout attach to 1 cyl baffle White wey l Violet Red i g i Oil Pressure c Switch xm Green Wire 25 155 06 Connector Valley Baffle Spark Plug Spark Plug Screw Cyl 2 Cyl 1 Cranking Relay Relay Stud Blue H B r Made Ignition White Carburetor Modules Violet _ Fuel Shut off c Solenoid Jr Flywheel Stator Assembly Rectifier ne 09 N A Lc Regulator o j 25 Amp Rectifier Regulator 15 Amp Starter Regulator Solenoid Connector Tang TT ER Block Solenoid Shift Starter Assembly Figure 8 6 Wiring Diagram 15 25
80. move the blower housing and other cooling shrouds Clean the cooling fins and external surfaces as necessary Make sure the cooling shrouds are reinstalled Cleanout kit 24 755 90 can be used for inspection and cleanout of the cooling fins without removing the blower housing or shrouds 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 4 TH16 amp TH18 Section 5 Fuel System and Governor Description Awarnine 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 fuel system and related components include the following Fuel Tank Fuel Lines In Line Fuel Filter Fuel Pump Carburetor Operation The fuel from the tank is moved through the in line filter and fuel lines by the fuel pump Fuel then enters the carburetor float bow and is moved into the carburetor body There the fuel is mixed with air This fuel air mixture is then burned in the engine combustion chambers Fuel Rec
81. mperatures 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 a minimum of 250 cold cranking amps should be sufficient for cranking The actual cold cranking requirement depends on engine size application and starting temperatures Cranking requirements increase as temperatures decrease and battery capacity shrinks Refer to the operating instructions of the equipment this engine powers for specific battery requirements If the battery charge is not sufficient 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 sparks open flames and other 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
82. n on workbench Figure 9 50 Removing Oil Pressure Relief Plug 2 Remove the connecting rod cap screws See 2 Use a small punch to drive out the relief valve Figure 9 53 retaining pin See Figure 9 51 3 Remove the relief valve spring and piston Figure 9 53 Removing Connecting Rod Caps 3 Before removing connecting rod caps note that Figure 9 51 Removing Relief Valve Retaining Pin the match marks on the rods face toward the outside of the crankcase Number the rod caps 4 Remove the two torx head screws securing the oil 1 is nearest the flywheel end Do not mix end screen to the bottom of the crankcase Remove caps and connecting rods the oil filter pick up screen See Figure 9 52 4 Lift connecting rod caps off crankshaft journals 9 14 Section 9 Disassembly Remove Crankshaft 3 Remove the oil seal and sleeve bearing from the 1 Lift the crankshaft assembly straight up out of the front end of the crankshaft Discard the oil seal crankcase half See Figure 9 54 See Figure 9 56 ng Figure 9 54 Removing Crankshaft Assembly i Figure 9 56 Sprocket Oil Seal and Sleeve Bearing Removed 2 Place crankshaft on workbench for further disassembly 4 Remove the oil seal and ball bearing from PTO end of crankshaft Use puller or press to remove 3 Loosely reassemble rod caps to the correct bearing TH18 engines have an additional snap connecting rod to keep them as sets ring on crankshaft to lock ba
83. nents but it is necessary to remove the starter from the engine Tape the commutator end cap to the starter frame so they cannot separate when the bolts are loosened for removal Remove the starter Section 8 Electrical System and Components Service the drive as follows Dust Cover Spring Retainer e Retaining 2 Dust Cover Spacer E d i Pinion Drive Nut Collar Figure 8 11 Drive Components UTE Bonded Inertia Drive Starter 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 11 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 2 Disassemble removal tool 25 761 18 by loosening the center screw one or two turns and removing the outer collar 3 Again referring to Figure 8 11 grasp the spring retainer and push it toward the starter compressing the anti drift spring and exposing the retaining ring 8 13 Section 8 Electrical System and Components 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 12 Slide the collar over the inner halves to hold them in position
84. ner from inside the starter 10 Tiea slip knot approximately 12 from the free handle Untie the single knot and remove the rope end of rope Hold the pulley firmly and allow it to retainer and handle rotate slowly until the slip knot reaches the guide bushing of housing 4 Hold the pulley firmly and untie the slip knot Allow the pulley to rotate slowly as the spring tension is 11 Slip the handle and rope retainer onto the rope released Tie a single knot at the end of the rope Install the rope retainer into the starter handle 5 When all spring tension on the starter pulley is released remove the rope from pulley 12 Untie the slip knot and pull on the handle until the rope is fully extended Slowly retract the rope into 6 Tie a single knot in one end of the new rope the starter 7 Rotate the pulley counterclockwise when viewed When the spring is properly tensioned the rope from pawl side of pulley until the spring is tight will retract fully and the handle will stop against Approximately 6 full turns of pulley the starter housing 8 Rotate the pulley clockwise until the rope hole in Pawls Dogs Replacement pulley is aligned with rope guide bushing of starter To replace the pawls follow disassembly steps 1 4 housing and reassembly steps 3 8 on the following pages A pawl repair kit is available which includes the following NOTE Do not allow the pulley spring to unwind components Enlist the aid of a helper if necessary
85. ner to air dry 1 Loosen the cover retaining knob and remove the 4 Saturate the precleaner with new engine oil cover Squeeze out all excess oil 2 Remove the wing nut s element cover and air 5 Reinstall the precleaner over the paper air cleaner cleaner element element 3 Remove the precleaner if so equipped from the 6 Reinstall the air cleaner cover Secure cover with paper element Service the precleaner the cover retaining knob 4 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 5 Reinstall the paper element precleaner element cover and wing nut s 6 Reinstall the air cleaner cover and secure cover with the retaining knob D Figure 4 3 Top Tank Air Clean Removed 2 er with Cover Figure 4 4 Removing Element on Standard Type 4 2 Section 4 Air Cleaner and Air Intake System amp Knob Knob Knob Gasket Knob Gasket Element Cover Element Cover _ Element Base Assembly Ss S Base Gasket Base Gasket Figure 4 5 Standard Air Cleaner System Figure 4 6 Top Tank Air Cleaner System Components Components 4 3 Section 4 Air Cleaner and Air Intake System Air Cleaner Components Whenever the air cleaner cover is
86. ng the M8x40 mm Hex Flange Screws 3 Pry between lifting tabs to separate the crankcase halves See Figures 9 43 and 9 44 Figure 9 45 Removing Lower Crankcase Half 5 Place lower half on workbench with oil drain holes down 9 12 Section 9 Disassembly Remove Oil Pump 1 Block oil pump from turning flywheel holding tool works well then remove the gear retaining screw and washers See Figure 9 46 Figure 9 48 Removing Oil Pump Cover 4 Note position of the O Ring ball bearing and oil seal inside cover Figure 9 46 Removing Oil Pump Drive Gear 5 Remove ball bearing wear plate oil pump shaft with rotor outer rotor and O Ring in recess of 2 Remove the drive gear from the pump shaft a crankcase See Figure 9 49 small gear puller may be necessary to pop it loose from the shaft See Figure 9 47 Figure 9 49 Oil Pump Ball Bearing Wear Plate Rotor Shaft and O Ring Figure 9 47 Oil Pump Gear Components 3 Remove the three screws from the pump cover and remove the cover See Figure 9 48 9 13 Section 9 Disassembly Remove Oil Pressure Relief Parts This should only be done if a problem is suspected or there is a specific reason for removal 1 Remove the allen head pipe plug from crankcase half See Figure 9 50 Figure 9 52 Removing Oil Filter Pick up Screen Remove Connecting Rods 1 Using the engine stand block place upper crankcase half upside dow
87. ng the engine or equipment always disconnect the spark plug lead s to prevent the engine from starting accidentally Ground the leads to prevent sparks that could cause fires Make sure the equipment is in neutral 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 Turn fuel shut off valve to off position Drain oil from crankcase and remove oil filter Remove air cleaner assembly Remove fuel tank if so equipped Remove muffler if so equipped Disconnect carburetor linkage Remove retractable starter or grass screen Remove blower housing 10 Remove electric starter motor 11 Remove side baffles 12 Remove ignition modules 13 Remove flywheel 14 Remove stator 15 Remove timing belt 16 Remove valve
88. ngertip and wipe it on the rubber gasket Figure 6 6 Hand Tighten New Filter in Clockwise Direction 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 1 2 turn 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 Figure 6 7 Replenish Oil to Proper Level 6 3 Section 6 Lubrication System Figure 6 8 Reinstall Dipstick 8 Reinstall the oil fill cap and dipstick 9 Start the engine and check for oil leaks Stop the engine allow a minute for the oil to drain down and recheck the level on the dipstick Oil Sentry General Some engines are equipped with an optional Oil Sentry oil pressure switch monitor If the pressure decreases 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 and make contact as the oil pressure decreases At oil pressure above approximately 3 0 5 0 psig the switch contacts open Below this pressure the switch contacts close On stationary or unattended applications pumps generators etc the pressure switch can be used to ground the ignition module to
89. nor Yoke and Cross 5 Hold governor halves together with one hand and Shaft slide camshaft out See Figure 9 31 Remove Rectifier Regulator 1 Onengines with top mounted fuel tank remove the wiring connector from the rectifier regulator 2 Remove the two mounting nuts holding the rectifier regulator to the valley baffle Remove the rectifier regulator and spacer See Figure 9 33 Figure 9 31 Hold Governor Together While Removing Camshaft 6 Lift out governor assembly 7 Remove the two hex flange screws from the rocker arm shaft See Figure 9 26 8 Lift rocker arm assembly off the valve b mechanism Figure 9 33 Removing Rectifier Regulator and Spacer 9 9 Section 9 Disassembly Remove Valley Baffle 2 Lift off the breather cover 1 Remove the hex flange screw from the wire retainer on the backside of the valley baffle 3 Remove and discard the gasket See Figure 9 36 2 Remove the hex flange screw from the front side of the baffle and remove the baffle See Figure 9 34 MT P Figure 9 36 Breather Cover Removal 4 Remove the two hex flange screws securing the breather housing to the crankcase Remove the housing there will be some resistance from the grommet underneath Figure 9 34 Removing Valley Baffle Remove Crankcase Breather 5 Remove the screw securing the breather stop and 1 Remove the two hex flange screws securing the reed See Figure 9 37 breather cover See Fig
90. nor body 7 Insert new coiled spring pin in the holes and drive in with a punch until flush with the governor body See Figure 11 29 Figure 11 29 Driving Coiled Spring Into Position in Governor Install Camshaft 1 Side 1 Lubricate the rocker arm shaft Install rocker arm assembly into position in chamber on the 1 side Torque screws to 4 0 N m 35 in Ibs See Figure 11 30 Figure 11 30 Installing Rocker Arm Assembly on 1 Side 3 Apply a small amount of grease to lip of oil seal 4 Hold the thrust washer inside the rocker chamber and insert the 1 side camshaft belt sprocket through the seal thrust washer and rocker arms 11 10 5 Install the C clip in groove to hold camshaft in place 6 Leave covers off until later Install Timing Belt 1 Install the flywheel key into the keyway of the crankshaft See Figure 11 31 Make sure that key is properly seated and parallel with shaft NOTE Make sure flywheel key is installed properly in the keyway The flywheel can become cracked or damaged if the key is not installed properly in the keyway Figure 11 31 Installing Key In Crankshaft 2 Remove the two screws and remove the stator to allow installation of the timing belt over the crankshaft sprocket 3 Rotate camshafts until timing holes in sprockets are horizontal and numbers are at the top See Figure 11 32 Section 11 Reassembly 5 Slide the crankshaft holding tool onto the Chec
91. nstall the cover plate and secure with two of the M8x40 mm crankcase bolts Refer to Section 2 Special Tools The valves would fall free without the tool on this engine design See Figure 9 59 E Figure 9 61 Removing Valves Figure 9 59 Special Valve Blocking Tools 9 16 TH16 amp TH18 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 Fuel System amp Governor Section 5 Retractable Starter Section 7 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 gasket remover or paint remover to remove the old RTV from the crankcase halves Do not scrape the surfaces when cleaning as this will damage the surfaces This could result in leaks Refer to A Guide to Engine Rebu
92. ommendations 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 recommended Such a container is easier to handle and heips eliminate spillage during refueling Donotuse gasoline left over from the previous season to minimize gum deposits in your fuel system and to ensure easy starting Donotaddoil to the gasoline e Donotoverfill 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 Gasoline Alcohol blends Gasohol up to 10 ethyl alcohol 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 gasoline blends up to a maximum of 15 MTBE by volume are approved as a fuel for Kohler engines Other gasoline ether blends are not approved Fuel Filter Most engines are equipped with an in line filter Periodically inspect the filter and replace when dirty with a genuine Kohler filter 5 1 Section 5 Fuel System and Governor Fuel System Tests When the engine starts hard o
93. ommunication involving an engine always give the Model Specification and Serial Numbers including letter suffixes if there are any Identification 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 Model No Twin Cylinder Engine Horizontal Crankshaft Version Code Horsepower S Electric Start 16 16 HP 18 2 18 HP Spec No Engine Model Code Code Model 52 TH16 54 TH18 Variation of Basic Engine Serial No 2605810332 Manufactured JI Factory Code 1996 1997 1998 1999 2000 Figure 1 2 Explanation of Engine Identification Numbers 1 3 Section 1 Safety and General Information Oil Recommendations Using the proper type and weight of oil in the crankcase is extremely important So is checking oil daily and changing oil regularly Failure to use the correct oil or using dirty oil causes premature engine wear and failure Cil Type Use high quality detergent oil of API American Petroleum Institute Service class SG or SH Select the viscosity based on the air temperature at the time of operation as shown in the following table RECOMMENDED SAE VISCOSITY GRADES ar Koh er Winter o 10W 30 5W 20 5W 30 Kohler Command D Ll L 20 10 30 40 E Lm pl i ix TEMPERATURE RANGE EXPECTED BEFORE NEXT OIL CHANGE Use of synt
94. on 2 of this manual for a listing of approved sealants Always use fresh sealant Using outdated sealant can result in leakage 1 Prepare the sealing surfaces of the crankcase halves as directed by the sealant manufacturer 2 Check to make sure that there are no nicks or burrs on the sealing surfaces of the halves 3 Apply a 1 5 mm 1 16 bead of silicone sealant to the surface of the lower crankcase half in pattern shown in Figure 11 13 Apply 1 5 mm 1 16 Sealant Bead of RTV Silicone Rubber or Equivalent Figure 11 13 Crankcase Sealant Pattern and Fastener Torque Sequence 4 Turn lower crankcase half upside down and carefully place on the upper half as shown in Figure 11 14 Make sure the snap ring on the ball bearing fits into the groove on the PTO end of the crankcase halves ae d bi Figure 11 14 Install Lower Crankcase To Upper Half 5 Loosely install the crankcase fasteners in proper position but do not tighten The two 70 mm long go in positions marked 1 and 2 the two 115 mm long go into positions marked 3 and 4 on the PTO side and the eight 40 mm long go into the remaining side holes See Figure 11 13 Section 11 Reassembly 6 Lay a straight edge or surface plate vertically across the bosses on the PTO face of the crankcase to check alignment between
95. on Ring to Groove Side Clearance TAHTO EE 0 040 0 085 mm 0 0016 0 0033 in cp 0 040 0 085 mm 0 0016 0 0033 in Middle Compression Ring to Groove Side Clearance Wish o IE 0 030 0 080 mm 0 0012 0 0031 in M m E e onte tete eege ed de me usi cioe im 0 030 0 076 mm 0 0012 0 0030 in Oil Control Ring to Groove Side Clearance Hohl 0 046 0 201 mm 0 0018 0 0079 in THATS Rincon pee oem eti eere tenera nud 0 070 mm 0 0028 in Top Compression Ring End Gap 0 180 0 380 mm 0 0071 0 0150 in 1 10 Section 1 Safety and General Information Piston Piston Rings and Piston Pin Cont Middle Compression Ring End Gap Ro ME 0 180 0 440 mm 0 0071 0 0173 in TEHT8 EE 0 180 0 450 mm 0 0071 0 0177 in Piston Thrust Face O D TH16 NOW weer 72 966 72 984 mm 2 8727 2 8734 in Max Wear EIImib iuca eter tete tacere tee e aee uen E 72 839 mm 2 8677 in TH18 M HE 74 966 74 984 mm 2 9514 2 9521 in Eve rg 74 839 mm 2 9464 in Piston Thrust Face to Cylinder Bore Running Clearance H e KEE 0 022 0 065 mm 0 0009 0 0026 in Hip EE 0 041 0 084 mm 0 0016 0 0033 in Speed Control Speed Control Bracket Assembly Fastener Torque 9 9 N m 88 in Ib Stator Stator Mounting Screw Torque ssonsssnseessersressersrnrresrrssrssrasnernnnn 4 0 Nm 35 in Ib Throttle Choke Controls Governor Control Leve
96. or use a C clamp to hold the pulley in Pawl Repair Kit postion Qty Dog Cam Center Screw Pawl Dog Spring 9 Insert the new rope through the rope hole in starter pulley and rope guide bushing of housing See Figure 7 4 Brake Spring Starter Pawl Dog Brake Washer Washer 7 2 Disassembly A WARNING Spring Under Tension Do not remove the center screw from 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 spring tension and remove the handle and 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 5 3 Remove the brake spring and brake washer See Figure 7 6 4 Carefully note the positions of the pawls and pawl springs before removing them Remove the pawls and pawl springs from the starter pulley e e n amp vn i EN 7 E Pawl mut Figure 7 5 Center Screw Washer and Pawl Retainer Section 7 Retractable Starter Affe Spring and SPIEL Figure 7 6 Brake Spring and Washer and Pawls 5 Rotate the pulley clockwise 2 full turns This will ensur
97. ore I D New Empire petites e EUR S 32 000 32 025 mm 1 2598 1 2608 in Bau uito ee ate ee tete E 24 800 24 825 mm 0 9764 0 9774 in Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 1 7 Section 1 Safety and General Information Camshaft Cont Bore I D Cont Max Wear Limit IS LU EE 32 04 mm 1 2614 in Det M ER 24 84 mm 0 9779 in Camshaft Bearing Surface O D New Fr n ege Eed 31 920 31 975 mm 1 2567 1 2589 in PRO AM cso RENE 24 720 24 775 mm 0 9732 0 9754 in Max Wear Limit BRON ee ES 31 91 mm 1 2562 in Flea iouis eerie EE 24 71 mm 0 9728 in Carburetor Carburetor Mounting Fasteners Torque ssssssesennssinsnrsrnrrnrerneen 9 9 N m 88 in Ib Carburetor Adjustments ssssssssssseseeeeeeeeeeenre nennen Non Adjustable Idle Fuel and Main Fuel Connecting Rod Cap Fastener Torque torque in increments G MM Step AOW an ee tdt cites deutet led deem 11 3 N m 100 in Ib Connecting Rod to Crankpin Running Clearance NOW TE EE 0 056 0 030 mm 0 0022 0 0012 in Max Wear Limit us NEES tete innate 0 07 mm 0 0028 in Connecting Rod to Crankpin Side Clearance sss 0 250 0 740 mm 0 0098 0 0291 in Piston Pin End I D NEW dues Hoi teet Itt a E sete esee Ur MUI 17 015 17 023 mm 0 6699 0 6702 in Max Wear Limit EE 17 04 mm 0 6708 in Crankcase Governor Cross Shaft Bore
98. over gasket Refer to page 2 2 fora listing of approved sealants Always use fresh sealant Using outdated sealant can result in leakage 5 Prepare the sealing surfaces of the breather cover and breather as directed by the sealant manufacturer 6 Check to make sure that there are no nicks or burrs on the sealing surfaces 7 Apply 1 5 mm bead of silicone sealant to breather cover gasket both sides See Figure 11 20 Breather Cover Gasket Apply 1 5 mm 1 16 Sealant Bead of RTV Silicone Rubber or Equivalent on Both Sides Figure 11 20 Sealant Pattern For Breather Cover Gasket 8 Position new breather cover gasket with large hole toward the flywheel end of the engine See Figure 11 19 9 Position the breather cover with the hole toward PTO end Install the two cover mounting screws and tighten these to 5 6 N m 50 in Ibs torque 10 Apply lubricant to nipple on bottom of breather to aid insertion into the grommet 11 Install breather assembly into grommet and press it down 12 Install breather retaining screws and tighten to 4 0 N m 35 in Ibs torque Top tank models have a wire retaining clip under the breather screw on the 1 side Install Oil Filter Adapter RTV silicone sealant is used as a gasket between the oil filter adapter and the crankcase Refer to page 2 2 for a listing of approved sealants Always use fresh sealant Using outdated sealant can result in leakage 1 Prepare the
99. owing procedure to accurately measure the piston to bore clearance 1 Usea 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 6 10 4 6 mm 0 24 in Measure 6 mm Above the Bottom of Piston Skirt at Right Angels to Piston Pin Figure 10 6 Measuring Piston Diameter 2 Use an 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 3 Piston to 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 flywheel if cracked Replace the flywheel the crankshaft and the key if flywheel key is sheared or the keyway is damaged Fuel Pump A mechanical type fuel pump is used on this engine The pump is an integral part of the valve cover on the 1 side The pump is driven off a lobe on the 1 side camshaft If faulty replace the 1 valve cover fuel pump assembly The pump itself is not serviceable Section 10 Inspection and Reconditioning Valves Hard starting or loss of power accompanied by high fuel consumption may be symptoms of faulty valves After removal clean the valve heads faces and stems with a power wire brush
100. position for loosening tightening or removing with a puller 2 1 Section 2 Special Tools RTV Silicone Sealant RTV silicone sealant is used as a gasket on the crankcase halves breather cover gasket and oil filter adapter The chart below lists some of the approved sealants RTV Sealants Figure 2 2 Loctite No 598 Syringe Dispenser Vendor No and Description S yring p RTV 102 White RTV 109 Gray NOTE Always use fresh sealant Using outdated GE RTV 103 Black RTV 154 Gray sealant can result in leakage Generally the RTV 106 Red RTV 156 Red shelf life of an unopened dispenser is about RTV 108 Clear RTV 1473 Black 1 year while that of a used one is not more 593 Black 598 Black than 6 months i SS WE SE NOTE Two styles of breather cover gaskets have been used One style has a sealant bead 6 Blue 6M Blue already on the surface and does not require Permatex 6B Blue 66B Clear any additional RTV 6C Blue 66C Clear NOTE Loctite No 598 is available in a handy 10 cc size syringe type dispenser with 2 disposable tips under Kohler Part No 25 597 04 2 2 TH16 amp TH18 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 For example a starting problem could be caused by an empty fuel tank Some common causes of engine troubles are listed below Use these to locate the cau
101. r Off Position of Key Switch Ignition Modules 008 012 in 20 30 mm Flywheel Air Gap Figure 8 3 Capacitive Discharge Ignition System The timing of the spark is controlled directly by the location of the flywheel magnet group as referenced to engine top dead center Figure 8 4 Capacitive Discharge Ignition Module 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 chamber 8 5 Section 8 Electrical System and Components Troubleshooting CD Ignition Systems Reported ignition problems are most often due to poor The CD ignition systems are designed to be trouble connections Before beginning the test procedure f
102. r Fastener Toroue sees 9 9 N m 88 in Ib Valve Cover Valve Cover Fastener Toroue eeeeeerreseerersnsrreierrrererreerereererrerrerret 5 6 Nem 50 in Ib Valves 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 EI 6 038 6 058 mm 0 2377 0 2385 in Max Wear Limit centeno neni 6 13 mm 0 2413 in Exhaust Valve Guide NOW eege ce ee EE x etd 6 038 6 058 mm 0 2377 0 2385 in Max Wear Limit E 6 19 mm 0 2437 in Valve Guide Reamer Size Standard iic at etude tete etude tense a is 6 048 mm 0 2381 in 0 25 mm OS hera a tpe dit dece eere e Ree days 6 298 mm 0 2480 in Intake Valve Minimum Lift 7 50 mm 0 295 in Exhaust Valve Minimum Lift eese 7 50 mm 0 295 in Nominal Valve Seat Ange 45 Measure 6 mm 0 236 in above the bottom of the piston skirt at right angles to the piston pin eee Section 1 Safety and General Information Valves Cont Valve Lash Intake oeste erede s Red erem ee e 0 013 0 064 mm 0 0005 0 0025 in EXHauSL ape ees Sa yore aeons dee EE ees 0 076 0 127 mm 0 0030 0 0050 in General Torque Values Metric Fastener Torque Recommendations for Standard Applications Tightening Torque N m in Ib or 10 Property Class Noncritical Fasteners
103. r 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 Test Conclusion 1 Check the following a Make sure the fuel tank contains clean fresh proper fuel b Make sure the vent in fuel tank cap is open c Make sure the fuel valve is open Check for fuel in the combustion chamber a Disconnect and ground spark plug leads b Close the choke on the carburetor c Crank the engine several times d Remove the spark plug and check for fuel at the tip 2 If there is fuel at the tip of the spark plug fuel is reaching the combustion chamber If there is no fuel at the tip of the spark plug check for fuel flow from the fuel tank Test 3 Check for fuel flow from the tank to the fuel pump a Remove the fuel line from the inlet fitting of fuel pump b Holdthe line below the bottom of the tank Open the shut off valve if so equipped and observe flow If fuel does flow from the line check for faulty fuel pump Test 4 If fuel does not flow from the line check for clogged fuel tank vent fuel pick up screen in line filter shut off valve and fuel lines If fuel does flow from the line check for faulty carburetor Refer to the Carburetor portions of this section Check the op
104. rankcase The rotating action of the cross shaft Adjustments is transmitted to the throttle lever of the carburetor through the governor lever and external linkage 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 Screws Cross Shaft Camshaft A KEN Shaft Seal Sprocket ER Flyballs Figure 5 8 Internal Governor Components on 2 Side Camshaft 5 10 Section 5 Fuel System and Governor Initial Adjustment Make this adjustment whenever the governor lever is loosened or removed from the cross shaft Adjust as follows 1 Make sure the throttle linkages are connected to the governor lever the bellcrank 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 TOWARDS the throttle control bracket as far as it will move wide open throttle and hold in 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 is adjusted by repositioning the governor spring in the holes on 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 Ad
105. rear stop collar Slide the front stop collar off of the armature shaft See Figure 8 22 Use a 1 2 or 13 mm deep socket and plastic hammer and tap the rear stop collar down to separate it from the retainer See Figure 8 23 Fron Stop Collar Figure 8 22 Removing the Front Stop Collar 8 17 Section 8 Electrical System and Components Plastic Hammer 1 2 13 mm Deep Socket Rear Stop Collar Figure 8 23 Separating the Rear Stop Collar From the Retainer 9 After 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 Part No 52 221 01 contains four replacement brushes and springs If replacement is necessary all four brushes should be replaced Figure 8 24 Replacement Brush 1 Remove brushes from brush holder and remove brush holder from frame 8 18 Trim Off Brush Lead Wire Figure 8 25 Cutting Brush Lead Wires From the Frame Posts 2 Cutthe brush lead wire at the edge of the post with a pair of nippers 3 File off burrs on the post LE Remove Burrs Figure 8 26 Filing Off Burrs on Posts 4 Place the plate of the spare brush on the welded portion of the brush lead wire and then crimp them together with a pair of pliers Be sure to align the edge of the lead wire Section 8 Electrical System and Components 5 Solder t
106. ree for the life of the engine Other than periodically check all external wiring Be certain all ignition related checking replacing the spark plugs no maintenance or Wires are connected including the spark plug leads timing adjustments are necessary or possible Be certain all terminal connections fit snugly Make Mechanical systems do occasionally fail or break sure the ignition switch is in the run position down however so the following troubleshooting information is provided to help you get to the root of a NOTE The CD ignition systems are sensitive to reported problem excessive load on the kill lead If a customer complains of hard starting low power or A WARNING Electrical Shock misfire under load it may be due to excessive draw on the kill circuit Disconnect any auxiliary kill wires or safety switches connected to the kill circuit and operate the engine to determine if the reported problem is gone Never touch electrical wires or components while the engine is running They can be sources of electrical shock Testing Procedure Test Conclusion Test for spark on both cylinders with Kohler 1 If one side is not firing check all wiring ignition tester Part No 24 455 02 Disconnect one connections and terminations on that side If spark plug lead and connect it to the post terminal wiring is okay replace ignition module and retest of the tester Connect the clip to a good ground for spark not to the spark plu
107. rew improperly set Low compression Stale fuel and or gum in carburetor Engine Overheats 1 IAN Air intake or grass screen cooling fins or cooling shrouds clogged Excessive engine load Low crankcase oil level High crankcase oil level Faulty carburetor Engine Knocks 2 3 4 Excessive engine load Low crankcase oil level Old or improper fuel Internal wear or damage 3 1 Section 3 Troubleshooting Engine Loses Power 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 0 Oo cmt amp o I Engine Uses Excessive Amount Of Oil Incorrect oil viscosity type Clogged or improperly assembled breather Worn or broken piston rings Worn cylinder bore Worn valve stems or valve guides Crankcase overfilled DARON Oil Leaks From Oil Seals Gaskets 1 Crankcase breather is clogged or inoperative 2 Loose or improperly torqued fasteners 3 Piston blowby or leaky valves 4 Restricted exhaust External Engine Inspection Before cleaning or disassembling the engine make a thorough inspection of its external appearance and condition This inspection can give clues to what might be found inside the engine and the cause when it is disassembled e Check for buildup of dirt and debris on the crankcase cooling
108. rottle 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 75 RPM Float Replacement If symptoms described in the carburetor troubleshooting guide indicate float level problems remove the carburetor from the engine to check and or replace the float Use Float Kit to replace float pin and inlet needle or valve 7 Float Kit Contains Float Valve float inlet needle Pin float 8 Gasket carburetor 3 Gasket air cleaner base 1 Remove the air cleaner and air intake 9 components from the carburetor as described in Section 4 2 Disconnect the fuel inlet line from the carburetor 3 Disconnect governor throttle linkage from the carburetor Disconnect lead wires from fuel shut off solenoid equipped carburetor Slide the carburetor off the retaining studs Remove the fuel bowl retaining nut or fuel shut off solenoid and drain fuel from the bowl into a safe container Remove the bowl from the carburetor body Turn the carburetor body upside down and check level of the float as shown in Figure 5 6 With the float needle valve fully seated 16 5 mm 65 should be measured from the body to float as indicated Don t
109. se cloth not emery cloth 2 Replace brushes if excessively or unevenly worn 1 Make sure the clutch or transmission is disengaged or placed in neutral This is especially important on equipment with hydrostatic drive The transmission must be exactly in neutral to prevent resistance which could keep the engine from starting 2 Check for seized engine components such as the bearings connecting rod and piston 8 12 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 Figure 8 10 UT Inertia Drive Electric Starter UT 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 It is not necessary to completely disassemble the starter to service the drive compo
110. sealing surfaces of the crankcase and oil filter adapter as directed by the sealant manufacturer 2 Check to make sure that there are no nicks or burrs on the sealing surfaces 3 Apply 1 5 mm bead of silicone sealant to crankcase oil filter adapter joint See Figure 11 21 Oil Filter Adapter Crankcase Apply 1 5 mm 1 16 Sealant Bead of RTV Silicone Rubber or Equivalent Figure 11 21 Sealant Pattern Oil Filter Adapter Crankcase Joint Section 11 Reassembly 4 Install oil filter adapter Install flat washer and turn nipple into adapter and crankcase Torque nipple to 40 7 N m 30 ft Ibs Install Oil Sentry Switch If So Equipped 1 Apply pipe sealant with Teflon to the threads of the switch Hand start the Oil Sentry switch into the oil filter adapter 2 Torque the Oil Sentry switch to a maximum of 3 4 N m 30 in Ibs as shown in Figure 11 22 Do not overtighten the switch The switch has pipe thread tapered and it will crack the adapter if overtightened Figure 11 23 Valley Baffle Installed Note Wiring Install Rectifier Regulator 3 Connect the wires to the Oil Sentry 1 On engines equipped with top mounted fuel tanks install the spacer and rectifier regulator See Figure 11 24 Figure 11 22 Torque Oil Sentry Switch Figure 11 24 Spacer and Rectifier Regulator SH Top Mount Fuel Tank Units Only Install Valley Baffle and Wiring 1 Before installing
111. seat inserts following the instructions provided with the valve seat cutter being used A typical cutter is shown in Figure 10 8 The final cut should be made with an 89 cutter as specified for the valve seat angle in Figure 10 7 With the proper 45 valve face angle as specified in Figure 10 7 and the valve seat cut properly 44 5 as measured from centerline when cut 89 this would result in the desired 0 5 1 0 full cut interference angle where the maximum pressure occurs on the outside diameters of valve face and seat 10 8 Figure 10 8 Typical Valve Seat Cutter Lapping Valves Reground or new valves must be lapped in to provide fit Use a hand valve grinder with suction cup for final lapping Lightly coat valve face with fine grade of grinding compound then rotate valve on seat with grinder Continue grinding until a smooth surface is obtained on the seat and on the valve face Thoroughly clean upper crankcase and valve in soap and hot water to remove all traces of grinding compound After drying parts apply light coating of SAE 10 oil to prevent rusting Pistons and Rings Inspection Scuffing and scoring of pistons and cylinder walls occurs when internal temperatures approach the welding point of the piston 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 p
112. sing factors Engine Cranks But Will Not Start Empty fuel tank Fuel shut off valve closed Dirt or water in the fuel system Clogged fuel line Spark plug lead disconnected Key switch or kill switch in off position Faulty spark plugs Faulty ignition module Carburetor solenoid malfunction 0 4090 20IN Engine Starts But Does Not Keep Running 1 Restricted fuel tank cap vent 2 Dirt or water in the fuel system 3 Faulty choke or throttle controls 4 Loose wires or connections that short the kill terminal of ignition module to ground 5 Faulty carburetor Engine Starts Hard PTO drive is engaged Dirt or water in the fuel system Clogged fuel line Loose or faulty wires or connections Faulty choke or throttle controls Faulty spark plugs Low compression Weak spark ONOARWN Engine Will Not Crank 1 NOONAN 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 ch oar won Dirt or water in the fuel system Spark plug lead disconnected Loose wires or connections Engine overheated Faulty ignition module Faulty spark plugs Engine Will Not Idle 1 OP OU om Restricted fuel tank cap vent Dirt or water in the fuel system Faulty spark plugs Idle speed adjusting sc
113. stalls at idle speed Screw 2 Engine runs rich indicated by 2a Clogged air cleaner Clean or replace black sooty exhaust smoke b Choke partially closed during operation Check the choke lever misfiring loss of speed and power linkage to ensure choke is operating properly governor hunting or excessive C Float level too high Separate fuel bowl from carburetor body throttle opening Free if stuck or replace float d Dirt under the fuel inlet needle Remove needle clean needle and seat and blow with compressed air e Bowl vent or air bleeds plugged Clean vent ports and air bleeds Blow out all passages with compressed air f Leaky cracked or damaged float Submerge float to check for leaks 3a Float level too low Separate fuel bowl from carburetor body Free if stuck or replace float b Idle holes plugged dirt in fuel delivery channels Clean main fuel jet and all passages blow out with compressed air 3 Engine runs lean indicated by misfiring loss of speed and power governor hunting or excessive throttle opening 4 Fuel leaks from carburetor 4a Float stuck See Remedy 2c b Dirt under fuel inlet needle See Remedy 2d c Bowl vents plugged Blow out with compressed air d Carburetor bowl gasket leaks Replace gasket Troubleshooting Checklist Make sure the air cleaner base and carburetor When the engine starts hard runs roughly
114. t Most are also equipped with an oiled foam precleaner which surrounds the paper element Two different types are used The standard type air cleaner is shown in Figure 4 1 while the top tank type air cleaner is shown in Figure 4 2 Internal components vary however the service recommendations are the same Figure 4 1 Standard Air Cleaner we nm Figure 4 2 Top Tank Air Cleaner Service Check the air cleaner daily or before starting the engine Check for and correct heavy 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 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 Loosen the cover 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 Paper Element Service detergent Rinse the precleaner thoroughly until Every 100 hours of operation more often under all traces of detergent are eliminated Squeeze extremely dusty or dirty conditions replace the paper out excess water do not wring Allow the element Follow these steps preclea
115. t The valve shown was in operation for almost 1000 hours under controlled test conditions Bad Condition The valve depicted here should be Coking 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 Section 10 Inspection and Reconditioning Excessive Combustion Temperatures The white Stem Corrosion Moisture in the fuel or condensation deposits seen here indicate very high combustion are the most common causes of valve stem corrosion temperatures usually due to a lean fuel mixture 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 Overheating An exhaust valve subject to overheating gasoline Gum is a prevalent cause of valve sticking will have a dark discoloration in the area above the The cure is to ream the valve guides and clean or valve guide Worn guides and faulty valve springs may replace the valves depending on their condition 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 G
116. tall tension spring See Figure 11 36 Ge Figure 11 36 Installing Tension Spring 2 Install flywheel drive cup if engine has retractable starter washer and retaining screw 3 Use a flywheel strap wrench or flywheel holding tool to hold the flywheel Torque retaining screw to 66 4 N m 49 ft Ibs See figure 11 37 Figure 11 37 Installing Flywheel Fastener mana DUUUUUUUMMMMMaa amp i o A A ALOOEXOOL CLIAXLILL LALILLALLZ L B amp 4 RSRR K I O OBOGILO xiLOLLXJLIOAU UL LECLERQLLELLLLOXLRlEESCLXdLAAEERALiERIAEZE 11 12 Section 11 Reassembly Install Ignition Modules 1 Figure 11 38 Adjusting Air Gap of Ignition Turn flywheel so ignition magnet is away from the module positions Install ignition module for the 42 side with the kill terminal toward the cylinder The 1 side should have the kill terminal facing away from the cylinder Pull the modules away from the flywheel and snug the screws to hold them in position Rotate the flywheel to position the magnet directly under an igniton module Insert a 0 25 mm 0 010 in flat feeler gauge or shim stock between the magnet and ignition module see Figure 11 38 Loosen the screws enough to allow the magnet to pull the module down against the feeler gauge Torque the two hex flange screws to 4 0 6 2 N m 35 55 in Ibs Repeat steps 3 through 5 for the other ignition module Rotate the flywheel ba
117. 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 carburetor To empty the system run the engine until the tank and system are empty 1 5 Section 1 Safety and General Information 4X MB X 1 25 6H 17 0 67 DEEP 4X 3 8 16 UNC 2B INCH 21 0 83 DEEP 196 85 7 75 D B C 4X 5 16 24 UNF 28 INCH 17 0 67 DEEP Mon V ke or N 127 00 5 00 D B C OIL FILTER M Ke zi d UNC 28 INCH b EN so 165 10 6 50 D B C L e 3 8 24 UNF 2B INCH 27 SS rea 25 4 1 00 DEEP 18 7 3 d di BEEN g 146 05 PILOT STANDARD 5 75 62 OIL FILTER 8X 9 09 36 THRI REMOVAL 110 36 S MOUNTING 4 31 39 22 4 L HOLE A 1 54 MOUNTING HOLE A eme SC 4 DIMENSIONS IN MILLIMETERS INCH EQUIVALENTS SHOWN IN FUEL PUMP INLET DIPSTICK OPTIONAL OIL FILL 5 PRONG CONNECTOR 25 40 1 00 21 Pu 86 OIL FILTER 4 00 P T O PILOT DEPTH 16 76 00 2X OIL DRAIN PLUG 2 99 3 8 N P T INCH 59 20 2 33 75 40 2 97 MOUNTING HOLE A KILOWATTS HORSEPOWER NEWTON METERS 97859895835 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 Figure 1 4 Typical Engine Dimensions Torque and Horsepower Curves OHC 16 18 HP 1 6 Section 1 Safe
118. the upper and lower halves Tap or shift the lower half as necessary to bring it into correct alignment 7 Torque all crankcase retaining fasteners to 24 4 N m 216 in Ibs in the sequence shown in Figure 11 13 Figure 11 17 Loosely Install Stator Mounting Screws Install Crankcase Breather 1 Install a new breather grommet in crankcase See Figure 11 18 d Figure 11 15 Tighten Crankcase Halves to Torque Stator Wire Routing 1 Route wiring so that leads are in 10 o clock position See Figure 11 16 Figure 11 18 Installing New Grommet in Crankcase 2 Install breather reed and reed retainer in breather housing and secure with hex flange screw Tighten screw to 4 0 N m 35 in Ibs torque See Figure 11 19 wl Figure 11 16 Route Wiring to Stator 2 Install the two stator mounting screws but do not tighten them at this time The stator will have to be removed later when installing the timing belt See Figure 11 17 11 6 Section 11 Reassembly Retainer Reed Reed TOM Cover Breather Hole at This End Screw p f T ma wrth H 7 Breather Gasket Breather Cover Large Hole This End Figure 11 19 Crankcase Breather Components 3 Examine the new replacement breather cover gasket If it has silicone beads imprinted on the surfaces go to step 8 If it does not have beads follow steps 4 7 4 RTV silicone sealant is used on both sides of the breather c
119. the valley baffle see Figure 7y 2 Secure rectifier regulator to valley baffle with two 11 23 carefully route wiring as follows screws See Figure 11 25 a Stator wiring harness must be between where valley baffle mounts b Ground wire attaches to lower mounting screw of baffle c Rectifier regulator feeds through cutout 11 8 Section 11 Reassembly Figure 11 25 Rectifier Regulator Installed On Valley Baffle 3 Connect terminal block to the rectifier regulator See Figure 11 26 Figure 11 26 Rectifier Regulator Connected le Figure 11 27 Install Cross Shaft and Yoke 2 Install Governor Camshaft 2 Side Slide governor cross shaft in from inside of valve box See Figure 11 27 Secure yoke with two allen head screws See Figure 11 27 Lubricate the rocker arm shaft Install rocker arm assembly in 2 chamber and torque retaining screws to 4 0 N m 35 in Ibs Grease lip on new camshaft oil seals both sides as installed in Section 10 Position governor assembly inside valve chamber Insert camshaft belt sprocket through seal governor and rocker arms See Figure 11 28 4 Route wire from breather to backside PTO end of baffle and attach wire clip to baffle with hex flange screw Figure 11 28 Installing Camshaft Through Governor 11 9 Section 11 Reassembly 6 Turn the camshatt until the hole aligns with the matching hole in the gover
120. ts and other components These kits are described below Refer to the Parts Manual for the engine being serviced to ensure the correct repair kits and replacement parts are used The Kohler part number is stamped on the choke side flange on top of the carburetor body Overhaul Kit With Gaskets Contains Description Gasket air cleaner base Gasket carburetor Screw throttle adjusting Gasket chamber screw Screw idle adjusting Float Pin float Valve float Gasket float chamber Spring throttle adjusting screw Spring idle adjusting screw Gasket passage cover 1 4 4 1 1 1 1 1 1 1 1 1 Section 5 Fuel System and Governor Choke Repair Kit With Gaskets Contains Gasket air cleaner base Gasket carburetor Screw valve set Valve choke Filter choke shaft Spring choke arm return Ring choke lever Collar choke Shaft choke assembly Lever choke assembly h h b b sch sch st YS Gasket Kit With Gaskets Contains Gasket air cleaner base Gasket carburetor Gasket chamber screw Gasket float chamber Gasket passage cover Solenoid Replacement Kit With Gaskets Contains Gasket air cleaner base Gasket carburetor Gasket solenoid Gasket chamber screw Holder solenoid Valve solenoid Reassembly Procedure Reassembly is essentially the reverse of the disassembly procedure Use new gaskets springs and adjusting screws as provided in the repair kit Also
121. ty and General Information Description TH16 amp TH18 General Specifications Power 3600 RPM corrected to SAE J1349 Ra EE 11 9 kW 16 HP ls MEET 13 4 kW 18 HP Peak Torque See Torque Curve 2500 RPM TEL irc tee etie I REND ORE 35 5 N m 26 2 ft Ib TEATS ss coc EE 40 N m 29 5 ft Ib Bore Be EE 73 mm 2 87 in BR e EE 75 mm 2 95 in Stroke TELTO dete cett Coste E rp eer e 62 mm 2 44 in HR e AE Stores eroe he ree recette PM echo vets eem tae 65 mm 2 56 in Displacement la NEE 519cc 31 7 cu in le EH 574cc 35 0 cu in Compression Ratio Run 7 81 THB E ante IR e eter e eU RE DR D needa t ES 8 41 Dry Weight nee rere EID IER eer RT 43 kg 90 Ib Oil Capacity with ter 1 4 L 1 5 U S gt Angle of Operation Maximum At Full Oil Level AII Directions 25 Blower Housing and Sheet Metal M5 Fasteners Torque cceccceesceceeeeeeeeeeeeeeeeeseeseeeseesecnsensetesseeesaes 4 0 N m 35 in Ib M6 Fasteners Torque into crankcase esses 7 3 N m 65 in Ib M6 Fasteners Torque into sheet baffle sseeseesssssese 4 0 N m 35 in Ib Rectifier Fastener Torque ccccccesesccceceseseeessaeeeseateesseneessseeeeessees 4 0 N m 35 in Ib Camshaft End Play FEV SIdeczzsez us eene ERE ect dee ee 0 000 0 700 mm 0 000 0 0275 in RR 0 000 1 300 mm 0 000 0 0512 in Running Clearance nennen 0 025 0 105 mm 0 0010 0 0041 in B
122. uides 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 seats 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 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 If the intake clearance exceeds 0 038 0 076 mm 0 0015 0 0030 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 Maximum I D wear on the intake valve guide is 6 13 mm 0 2413 in while 6 19 mm 0 2437 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 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 replace with new valves Valve Seat Inserts Hardened steel alloy intake and exhaust valve seat inserts are press fitted into the upper crankcase half The inserts are not replaceable on the engines but can be reconditioned if not too badly pitted or distorted If cracked or badly warped upper crankcase should be replaced Recondition the valve
123. up Hold the handle in this position and tighten the screws securely See Figure 11 52 Figure 11 52 Installing Retractable Starter Install Carburetor and Controls 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 governor spring in hole locations marked during disassembly Spring coils should be closest to the pivot lever Connect governor link to pivot lever and lock with bushing clip Reattach choke link to choke lever and carburetor Connect throttle link and linkage spring to pivot lever and lock with bushing clip 10 11 12 Figure 11 53 Connecting Fuel Line To Carburetor 3 Section 11 Reassembly Hold the carburetor control bracket governor lever assembly just above the engine and reconnect the solenoid leads Slide a new carburetor gasket onto the manifold studs followed by the carburetor new elbow gasket and the elbow Slide the governor lever onto the governor shaft but do not tighten it Mount throttle control bracket to crankcase with four hex flange screws and then tighten all baffles and blower housing screws On standard models apply Loctite to the bottom threads of the air cleaner stud and reinstall it in the top of the crankcase Remove the hex flange nuts from the stud and install them on
124. ure 9 35 Figure 9 37 Breather Stop and Reed Removal Figure 9 35 Removing Crankcase Breather Cover Screws 6 Remove rubber grommet from bottom side of the breather 9 10 Section 9 Disassembly Remove Oil Sentry Switch If So Equipped 1 Disconnect the wire lead from the Oil Sentry Switch 2 Remove the Oil Sentry switch from the oil filter adapter See Figure 9 38 Figure 9 38 Removing Oil Sentry Switch Remove Oil Filter Adapter 1 Remove oil filter nipple with an 8 mm or 5 16 allen head Turn nipple in counterclockwise direction See Figure 9 39 Figure 9 39 Removing Oil Filter Nipple 2 Remove the oil filter adapter as shown in Figure 9 40 Figure 9 40 Oil Filter Adapter and Nipple Separate Crankcase Halves 1 Remove the two 70 mm long screws securing crankcase halves on flywheel side See Figure 9 41 Figure 9 41 Removing the M8x70 mm Hex Flange Screws 9 11 Section 9 Disassembly 2 Using the engine stand the largest piece in set 28 761 02 see Section 2 Special Tools turn crankcase assembly upside down so that the lower half is on top Remove the remaining 10 crankcase screws holding the crankcase halves together PTO side has two 115 mm long screws all others are 40 mm long See Figure 9 42 Figure 9 44 Splitting Crankcase Halves 4 Liftthe lower crankcase half off the upper half See Figure 9 45 Figure 9 42 Removi
125. ury death or substantial property damage if the warning is ignored AA CAUTION Caution is used to indicate the presence of a hazard that will or can cause minor personal injury or property damage if the warning 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 4b WARNING 4y WARNING 4 WARNING Accidental Starts can cause severe injury or death Rotating Parts can cause severe injury Hot Parts can cause severe burns Do not touch engine while operating or just after stopping Disconnect and ground spark plug Stay away while engine is in leads before servicing operation Accidental Starts Rotating Parts Hot Parts Before servicing the engine or Keep hands feet hair and Engine components can get equipment always disconnect the clothing away from all moving extremely hot from operation To spark plug leads to prevent the parts to prevent injury Never prevent severe burns do not engine from starting accidentally operate the engine with covers touch these areas while the Ground the leads to prevent shrouds or guards removed engine is running or immediately sparks that could cause fires after it is turned off Never operate Make sure the equipment is in the
126. vice Housing 1 Carefully inspect the rope pawls housing center screw and other components for wear or damage 3 Install the pawl springs and pawls into the starter pulley See Figure 7 10 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 rewind a spring that has come out of the keeper Order and install a new spring and keeper assembly 4 Clean all old grease and dirt from the starter components Generously lubricate the spring and center shaft with any commercially available Figure 7 10 Installing Pawis and Paw Springs bearing grease 4 Place the brake washer in the recess in starter pulley over the center shaft 7 4 Lubricate the brake spring sparingly with grease Place the spring on the plain washer Make sure the threads in center shaft remain clean dry and free of grease and oil Apply a small amount of Loctite No 271 to the threads of the center screw Install the center Screw with washer and retainer to the center shaft Torque the screw to 7 4 8 5 N m 65 75 in Ib Tension the spring and install the rope and handle as instructed in steps 6 through 12 under Rope Replacement on page 7 2 Install the starter to the engine blower housing See Figure 7 11 Section 7 Retractable Starter

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