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Service Manual KT715-KT745

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1. Pug E MainJet F Float NN Shut off Solenoid Fuel Bowl Assembly Choke Lever 32 690 03 Rev Fuel System pre y D IA o P H A Idle Speed Screw B Carburetor Body C Mandt D Float Assembly G Choke Lever Engines in this series are equipped with either a Keihin or Walbro fixed main jet carburetor Most carburetors utilize a fuel shut off solenoid and feature a self relieving choke Troubleshooting Checklist When engine starts hard runs rough or stalls at low idle speed check these areas before adjusting or disassembling carburetor 1 Make sure fuel tank is filled with clean fresh gasoline 2 Make sure fuel tank cap vent is not blocked and is operating properly 3 Make sure fuel is reaching carburetor This includes checking fuel shut off valve fuel tank filter screen in line fuel filter fuel lines and fuel pump for restrictions or faulty components as necessary 4 Make sure air cleaner base and carburetor are securely fastened to engine using gaskets in good condition 5 Make sure air cleaner element including precleaner if equipped is clean and all air cleaner components are fastened securely 6 Make sure ignition system governor system exhaust system and throttle and choke controls are operating properly KohlerEngines com 21 Fuel System Troubleshooting Carburetor Related Causes Condition Engine runs
2. NOTE RTV sealant should be allowed to cure a minimum of 1 hour before engine is started 1 Install breather filter between 2 ribs inside breather chamber 2 Make sure sealing surfaces are clean and free of nicks or damage 3 Apply a 1 5 mm 1 16 in bead of RTV sealant to sealing surface of breather cover See sealant pattern 4 Immediately install cover onto crankcase Do not allow RTV sealant to come into contact with any other components 5 Secure breather cover with M5 screws Torque screws in sequence shown to 6 2 N m 55 in Ib into a new cored hole or 4 0 N m 35 in Ib into a used hole 6 Attach breather hose if disconnected earlier KohlerEngines com 5 Reassembly Crankshaft Governor Gear Oil Pump Components C Valve Tappets Regulating Pin overnor Gear Governor Cross DE GENET Oil Sentry4y Ground Strap Location Outer Gerotor Gear CE a kl as 1 CB a Piston and Connecting Rod Details Install Governor Cross Shaft Lubricate governor cross shaft bearing surfaces in crankcase with engine oil Slide lower washer onto governor cross shaft and install cross shaft from inside of crankcase Install nylon washer onto governor cross shaft then start push on retaining ring Hold cross shaft up in position place a 0 50 mm 0 020 in feeler gauge on top of nylon washer and push retaining ring down shaft to se
3. Carefully inspect valve mechanism parts Inspect valve Although these symptoms could also be attributed to springs and related hardware for excessive wear or worn rings remove and check valves first After removal distortion Check valves and valve seat area or inserts clean valve heads faces and stems with a power wire for evidence of deep pitting cracks or distortion brush Then carefully inspect each valve for defects such as warped head excessive corrosion or worn stem end Replace valves found to be in bad condition 32 690 03 Rev KohlerEngines com 49 Disassembly Inspection and Service Valve Guides If a valve guide is worn beyond specifications it will not guide 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 valve guide and using a split ball gauge measure inside diameter of guide Then using an outside micrometer measure diameter of valve stem at several points on stem where it moves in valve guide Use largest stem diameter to calculate clearance by subtracting stem diameter from guide diameter If intake clearance exceeds 0 040 0 078 mm 0 0016 0 0031 in or exhaust clearance exceeds 0 052 0 090 mm 0 0020 0 0035 in determine whether valve stem or guide is responsible for excessive clearance Maximum I D wear on intake valve guide is 7 140 mm 0 2811 in while 7 1
4. Kohler genuine service parts can be purchased from Kohler authorized dealers To find a local Kohler authorized dealer visit KohlerEngines com or call 1 800 544 2444 U S and Canada 32 690 03 Rev KohlerEngines com Maintenance OIL RECOMMENDATIONS We recommend use of Kohler oils for best performance Other high quality detergent oils including synthetic of API American Petroleum Institute service class SJ or higher are acceptable Select viscosity based on air temperature at time of operation as shown in table below e Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running 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 Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent NOTE E15 E20 and E85 are NOT approved and should NOT be used effects of old stale or contaminated fuel are not warrantable Fuel must meet these requirements e Clean fresh unleaded gasoline e Octane rating of 87 R M 2 or higher e Research Octane Number RON 90 octane minimum e Gasoline up to 10 ethyl alcohol 90 unleaded is acceptable e Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blend max 15 MTBE by volume are approved e Do not
5. ground lead Keihin carburetors only Discard gasket and screws only 5 Remove idle speed adjusting screw and spring from carburetor Discard parts 6 Clean carburetor bowl and inlet seat areas as required 7 Carefully remove main jet from carburetor After main jet is removed on some carburetors main nozzle can be removed through bottom of main tower Note orientation direction of nozzle Save parts for cleaning and reuse Position of slow jet varies and is removable only on some styles of carburetors See correct illustration for corresponding style of carburetor showing location Save parts for cleaning and reuse unless a jet kit is also being installed Clean slow jet using compressed air Do not use wire or carburetor cleaner 9 Carburetor is now disassembled for appropriate cleaning and installation of parts in overhaul kit Further disassembly is not necessary Throttle shaft assembly fuel inlet seat and idle fuel adjustment screw are non serviceable items and should not be removed Choke shaft assembly is serviceable however it should not be removed unless a choke repair kit will be installed NOTE KohlerEngines com 23 Fuel System For Keihin Carburetors Only 10 11 12 13 14 19 16 17 18 19 20 21 22 23 24 25 26 24 To install choke repair kit go to step 10 otherwise go to step 21 Remove and discard plastic cap from top of choke lever shaf
6. An assistant may be needed to hold breaker bar during testing If engine is mounted in a piece of equipment it may be possible to hold it by clamping or wedging a driven component Just be certain that engine cannot rotate off of TDC in either direction Install adapter into spark plug hole but do not attach it to tester at this time Turn regulator knob completely counterclockwise Connect an air source of at least 50 psi to tester Turn regulator knob clockwise increase direction until gauge needle is in yellow set area at low end of scale Connect tester guick connect to adapter hose While firmly holding engine at TDC gradually open tester valve Note gauge reading and listen for escaping air at combustion air intake exhaust outlet and crankcase breather 99 NOS OT om Condition Conclusion Gauge reading in low green zone Gauge reading in moderate yellow zone Engine is still usable but there is some wear present Customer should start planning for overhaul or replacement Gauge reading in high red zone Rings and or cylinder have considerable wear Engine should be reconditioned or replaced 18 KohlerEngines com 32 690 03 Rev AIR CLEANER These systems are CARB EPA certified and components should not be altered or modified in any way Air Cleaner Components 2 A Precleaner B Paper Element Air Cleaner Cover D Blower Housing Air Cleaner Cover Lever NOTE Operating engine with loose o
7. Carbon Canister Canister Breather e Oer F To Carburetor For engine to be Tier IIl compliant it may be fitted with a Kohler supplied canister vapor recovery system or a system developed and installed by Original Equipment Manufacturer OEM Details on Kohler system are included below Operation Maintenance Fuel vapors travel from fuel tank through tubing to On Kohler supplied canisters breather filter can be carbon canister On intake stroke of engine fuel vapors removed and cleaned with hot soapy water dried and are drawn in through a port in carburetor and burned reinstalled Do not oil breather screen This is done with fuel charge periodically or if system operation is suspect Carbon canister is sealed and requires no maintenance In some applications or installations OEM will have installed a different canister or fuel vapor recovery system See OEM equipment documentation for service or maintenance information 42 KohlerEngines com 32 690 03 Rev Emission Compliant Systems SECONDARY EMISSION COMPLIANT SYSTEM Twin Secondary Air Induction System Secondary Air Hose To Exhaust F Valve Assembly ru Manifold E Hose To Carburetor r Inlet Screen For engine to be Tier III compliant it may be fitted with a secondary air induction system SAI Operation Maintenance Intake pulse of engine activates secondary air valve Air inlet screen in secondary air valve can be removed Air is drawn through an inlet screen of
8. Install Cylinder Heads NOTE Match numbers embossed on cylinder heads and crankcase NOTE When installing cylinder heads new screws should always be used New screws are supplied in gasket sets NOTE Push rods should always be installed in same position as before disassembly 62 KohlerEngines com 1 Check to make sure there are no nicks or burrs on sealing surfaces of cylinder head or crankcase Make sure dowel locating pins are in lower 2 cylinder bolt holes on each side 2 Install a new cylinder head gasket with printing up on each side Install each cylinder head and start 4 new screws 4 Torque screws in 2 stages first to 22 6 N m 200 in Ib then finally to 41 8 N m 370 in Ib following sequence Install Rocker Arms 1 Note mark or tag identifying push rod as either intake or exhaust and cylinder 1 or 2 Check each push rod is straight and not bent Dip ends of push rods in engine oil and install in their original positions making sure each push rod ball seats in its tappet socket 2 Install guide plate and studs Torque studs to 11 3 N m 100 in Ib 3 Apply grease to contact surfaces of adjusters rocker arms and rocker arm pivots Install rocker arms and rocker arm pivots onto appropriate cylinder head and install adjuster finger tight Make sure set screw is backed out until flush with adjuster gt 32 690 03 Rev Reassembly Install Valve Covers Valve Cover RTV Sealant Adju
9. Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled Accidental Starts can cause severe injury or death Disconnect and ground spark plug lead s before servicing Do not touch wires while engine is running CAUTION Damaging Crankshaft and Flywheel can cause Ro personal injury CN Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions and procedures when installing flywheel CAUTION 3 Electrical Shock can cause injury Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery WARNING Hot Parts can cause zh severe burns tn M ih Do not touch engine while operating or just after stopping Never operate engine with heat shields or guards removed WARNING Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and instructions on
10. Loctite 5900 or 5910 3 Immediately install breather reed cover over mounting stud and onto crankcase Do not allow RTV sealant to come in contact with breather reed or reed sealing surface 4 Secure with a new sealing washer and M5 nut Torque nut to 1 3 N m 12 in Ib Check that a complete seal has occurred by RTV sealant being squeezed out around entire flange perimeter Install Stator and Backing Plate 1 Apply pipe sealant with Teflon Loctite PST 592 or equivalent to stator mounting holes 2 Position stator aligning mounting holes so leads are at bottom toward crankcase 3 Install and torque screws to 8 8 N m 78 in Ib 4 Install backing plate Secure with screws Torque Screws in a crisscross pattern to 7 3 N m 65 in Ib 32 690 03 Rev Reassembly Install Flywheel and Fan A CAUTION Damaging Crankshaft and Flywheel can cause personal injury Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions and procedures when installing flywheel NOTE Before installing flywheel make sure crankshaft taper and flywheel hub are clean dry and completely free of lubricants Presence of lubricants can cause flywheel to be overstressed and damaged when screw is torqued to specifications NOTE Make sure flywheel key is installed properly in keyway Flywheel can become cracked or damaged if key is n
11. T 7 Z 7 YYW Yj f Z 4 il UP A FixedGuard B AirCleanerCover C Debris Screen D BlowerHousing E HoseClamp F FuelPump G HosClp H Fuelline 1 fFuelFiter J OilFilter K OuterBaffle L ElectricStater M InnerBafle N Ignition Module O Intake Manifold P Carburetor A Gasket R AirCleanerBase S Air Cleaner Element T Rectifier Regulator U W Dipstick Tube Oil Fill Dipstick Breather Hose 32 690 03 Rev KohlerEngines com 45 Disassembly Inspection and Service Clean all parts thoroughly as engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many Control Bracket Components commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow manufacturer s instructions and safety precautions carefully Make sure all traces of cleaner are removed before engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down lubricating properties of engine oil Disconnect Spark Plug Leads NOTE Pull on boot only to prevent damage to spark plug lead 1 Disconnect leads from spark plugs 2 Shut off fuel supply Remove Throttle Controls Drain Oil From Crankcase and Remove Oil Filter 1 Remove oil fill
12. baffles Remove Ignition Modules 1 Rotate flywheel so magnet is away from modules 2 Disconnect lead from each ignition module 3 Remove mounting screws and ignition modules Note position of ignition modules Remove Intake Manifold and Rectifier Regulator 1 Remove screws securing intake manifold to cylinder heads Note which screws hold wiring clamp s 2 Remove intake manifold and O rings Leave wiring harness attached to manifold 3 Remove screws securing rectifier regulator to backing plate and disconnect plug 4 Use tip of a small screwdriver or similar small flat tool to bend locking tang then remove B center lead from terminal plug This will allow intake manifold to be removed with wiring harness intact 47 Disassembly Inspection and Service Cylinder Head Components AR adi m M na INN 3 1D itp i u A Gasket B Valve C CylinderHead D Valve Spring Cap E Valve Stem Seal F Valve Spring G Valve Spring Keeper H Stud Guide Plate I SparkPlug 1 J M Rocker Arm Pivots NJ Adjusters Remove Spark Plugs Remove spark plug from each cylinder head Remove Valve Covers and Cylinder Heads NOTE Valve cover is sealed to cylinder head using RTV silicone sealant When removing valve Cover use care not to damage gasket surfaces of cover and cylinder head To break RTV seal hold a block of wood against 1 flat face of valve cover Strike wood firmly with a ma
13. be caused by an empty fuel tank Some general common causes of engine troubles are listed below and vary by engine specification Use these to locate causing factors Engine Cranks But Will Not Start e Battery connected backwards e Blown fuse e Carburetor solenoid malfunction e Choke not closing e Clogged fuel line or fuel filter Diode in wiring harness failed in open circuit mode DSAI or DSAM malfunction Empty fuel tank Faulty electronic control unit Faulty ignition coil s Faulty spark plug s Fuel pump malfunction vacuum hose clogged or leaking Fuel shut off valve closed Ignition module s faulty or improperly gapped Insufficient voltage to electronic control unit Interlock switch is engaged or faulty Key switch or kill switch in OFF position Low oil level e Quality of fuel dirt water stale mixture e SMART SPARK malfunction e Spark plug lead s disconnected Engine Starts But Does Not Keep Running e Faulty carburetor Faulty cylinder head gasket Faulty or misadjusted choke or throttle controls Fuel pump malfunction vacuum hose clogged or leaking Intake system leak Loose wires or connections that intermittently ground ignition kill circuit e Quality of fuel dirt water stale mixture e Restricted fuel tank cap vent Engine Starts Hard e Clogged fuel line or fuel filter e Engine overheated e Faulty ACR mechanism e Faulty or misadjusted choke or throttl
14. dipstick and oil drain plug 2 Allow ample time for oil to drain from crankcase and oil filter 3 Remove and appropriately discard oil filter Remove Muffler Remove exhaust system and attaching hardware from engine Remove Fuel Pump if equipped A WARNING Explosive Fuel can cause fires and severe burns D A Choke Linkage 8 Throne Linkage C Govemorlever D Governor Spring E Cross Shat F Como Bracket G Dampener Spring Do not fill fuel tank while engine is hot or running 1 Remove screws securing throttle control bracket to Gasoline is extremely flammable and its vapors can cylinder heads explode if ignited Store gasoline only in approved 2 Disconnect choke linkage from choke actuator lever containers in well ventilated unoccupied buildings Unhook governor spring and dampener spring from away from sparks or flames Spilled fuel could ignite governor lever Note hole locations for reassembly if it comes in contact with hot parts or sparks from 1 Disconnect pulse vacuum hose and outlet fuel line Loosen nut and remove governor lever from cross shaft from fuel pump Leave lever attached to throttle linkage 2 Remove mounting screws unhook outlet hose from blower housing clip and remove fuel pump from blower housing Remove Blower Housing and Outer Baffles 1 Remove air cleaner cover 2 Remove screws securing blower housing 3 Remove blower housing from eng
15. engine and can cause death if inhaled with covers shrouds or guards removed Hotating Parts can cause severe injury Stay away while engine is in operation A partial vacuum should be present in crankcase when engine is operating Pressure in crankcase normally caused by a clogged or improperly assembled breather can cause oil to be forced out at oil seals gaskets or other available spots Crankcase vacuum is best measured with either a water manometer or a vacuum gauge Complete instructions are provided in kits To test crankcase vacuum with manometer To test crankcase vacuum with vacuum pressure gauge 1 Insert rubber stopper into oil fill hole Be sure pinch 1 Remove dipstick or oil fill plug cap clamp is installed on hose and use tapered adapters 5 install adapter into oil fill dipstick tube opening n Porno upside down over end of a small diameter dipstick manometer tube Leave other tube open to k tube or directly into engine if a tube is not used atmosphere Check that water level in manometer is ince barbed u fitting into hole in stopper at O line Make sure pinch clamp is closed 2 Start engine and run no load high speed 3 Nee and one B nalog tester needle movement to left of 0 is a 3 Open clamp and note water level in tube vacuum and movement to right indicates a Level in engine side should be a minimum of pressure 10 2 cm 4 in above level in open side Digital tester depress test button
16. hose 2 Attach pulse hose to fuel pump and secure with a clamp Mount fuel pump to blower housing with screws Torque screws to 2 8 N m 25 in Ib 3 Connect inlet and outlet fuel lines to pump Route inlet fuel line through fuel line clamp if used as shown Install Muffler 1 Install muffler and attaching hardware to muffler bracket Torque screws to 9 9 N m 88 in Ib 2 Install M8 nuts or 5 16 18 head capscrews based on head design to secure muffler Torque nuts to 24 4 N m 216 in Ib or capscrews to 16 9 N m 150 in Ib Install Oil Filter and Fill Crankcase with Oil NOTE Make sure oil drain plug is installed and torqued to specification to prevent oil leakage 1 Install oil drain plug Torque plug to 13 6 N m 10 ft Ib 2 Place new filter in shallow pan with open end up Fill with new oil until oil reaches bottom of threads Allow 2 minutes for oil to be absorbed by filter material 3 Apply a thin film of clean oil to rubber gasket on new filter 4 Refer to instructions on oil filter for proper installation 5 Fill crankcase with new oil Level should be at top of indicator on dipstick 6 Reinstall oil fill dipstick and tighten securely Connect Spark Plug Leads Connect leads to spark plugs Prepare Engine for Operation Engine is now completely reassembled Before starting or operating engine be sure to do following 1 Make sure all hardware is tightened securely 2 Make
17. kill lead to shut it down Because you have interrupted kill circuit it may not stop using switch Isolate and verify trouble is within engine 1 Locate connectors where wiring harnesses from engine and equipment are joined Separate connectors and remove white kill lead from engine connector Rejoin connectors and position or insulate kill lead terminal so it cannot touch ground Try to start engine to verify whether reported problem is still present Condition Possible Cause Conclusion Problem goes away Electrical System Check key switch wires connections safety interlocks etc Problem persists Ignition or Electrical System Leave kill lead isolated until all testing is completed Identify white kill lead of engine wiring harness connector Establish a connection to a known good ground location Engine should kill completely If not or only one cylinder is affected test ignition modules Test for Spark NOTE If 2 testers are available testing can be performed simultaneously for both cylinders However if only 1 tester is available 2 individual tests must be performed Side not being tested must have spark plug lead connected or grounded Do not crank engine or perform tests with 1 spark plug lead disconnected and not grounded or permanent system damage may occur 1 With engine stopped disconnect 1 spark plug lead Connect spark plug lead to post terminal of spark tester and attach tester clip to a good engine grou
18. lead and 1 black lead to terminals on being used Turn on power switch POWER light open end of tandem adapter lead connections are should be illuminated and 1 of 4 status lights may be not location specific on as well This does not represent condition of part 4 Connect remaining black lead from tester to 1 outer 4 Press TEST button until a click is heard and then AC terminal on rectifier regulator release Momentarily 1 of 4 status lights will 5 Plug tester into proper AC outlet power for tester illuminate indicating condition of part being used Turn on power switch POWER light should be illuminated and 1 of 4 status lights may be on as well This does not represent condition of part 6 Press TEST button until a click is heard and then release Momentarily 1 of 4 lights will illuminate indicating partial condition of part Condition Conclusion 25 amp 12 15 amp OK green light comes on and stays steady Disconnect tester black lead Part is good and may be used attached to 1 AC terminal and reconnect it to other AC terminal Repeat test If OK green light comes on again part is good and may be used NOTE Aflashing LOW light can also occur as Rectifier regulator is faulty and should not be used a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure Other lights come on 34 KohlerEngines com 32 690 03 Rev Electrical System 12 15 25 Amp Battery C
19. lead s and negative battery cable Start engine and perform Idle Speed RPM Adjustment High Altitude Operation Engines may require a high altitude carburetor kit to ensure correct engine operation at altitudes above 1219 meters 4000 ft To obtain high altitude kit information or to find a Kohler authorized dealer visit KohlerEngines com or call 1 800 544 2444 U S and Canada This engine should be operated in its original configuration below 1219 meters 4000 ft as damage may occur if high altitude carburetor kit is installed and operated below 1219 meters 4000 ft 32 690 03 Rev Fuel System UNITIZED THROTTLE AND CHOKE CONTROL Some engines are equipped with a unitized throttle and choke control This assembly controls choke and engine speed with a single lever Engines with a unitized throttle and choke control will have either a left side pull or a right side pull Governor Throttle Control Connections E Left Side Pull B Cable Clamp L Speed Control Lever Speed Setting Lever Choke Lever Right Side Pull Contact Point H Choke Control Cable Dual Control High ES Throttle Control Cable Lever Stop Screw Do High Led MNO q Choke Linkage Not Remove m Hen bash d Control bash d 32 690 03 Rev KohlerEngines com 25 Fuel System Throttle Cable Adjustment NOTE Choke is placed ON by moving throttle control slightly past fast position If throttle control does not have a d
20. m 20 ft Ib Module Fastener 4 0 6 2 N m 35 55 in Ib Rectifier Regulator Fastener 4 0 N m 35 in Ib Intake Manifold Mounting Fastener torque in 2 increments first to 7 4 N m 66 in Ib finally to 9 9 N m 88 in Ib Muffler M8 Hex Nuts 24 4 N m 216 in Ib 5 16 18 Capscrew 16 9 N m 150 in Ib Bracket Screw 9 9 N m 88 in Ib Oil Pan 244 Nm 216 in Ib Oil Pump Screw no torque sequence 9 9 N m 88 in Ib Oil Sentry Pressure Switch 4 5 N m 40 in Ib Solenoid Starter Mounting Hardware 4 0 6 0 N m 35 53 in Ib m Nut Positive Brush Lead 8 0 11 0 N m 71 97 in Ib Speed Control Bracket 7 3 N m 65 in Ib into used holes Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 32 690 03 Rev KohlerEngines com 7 Specifications TORQUE SPECIFICATIONS KT715 KT725 KT730 KT735 KT740 KT745 Starter Assembly Thru Bolt Inertia Drive 4 5 5 7 Nm 40 50 in Ib Solenoid Shift 5 6 9 0 N m 49 79 in Ib Mounting Screw 23 8 N m 211 in Ib Brush Holder Mounting Screw 2 5 3 3 N m 22 29 in Ib Stator Mounting Screw 8 8 N m 78 in Ib Valve Cover 3 6 Nm 85 in Ib CLEARANCE SPECIFICATIONS KT715 KT725 KT730 KT735 KT740 KT745 Camshaft End Play 0 06 0 40 mm 0 0024 0 0157 in Running Clearance 0 040 0 077 mm 0 0016 0 0030 in 20 000 20 025 mm 0 7874 0 7884 in Max Wear Limit 20
21. on top of tester If level in engine side is less than specified low no Cr n a ankcase vacuum should be a minimum of 10 2 cm vacuum or level in engine side is lower than level in 4 in of water If reading is below specification or if open side pressure check for conditions in table pressure is present check table below for possible below causes and conclusions 4 Close pinch clamp before stopping engine Condition Conclusion Crankcase breather clogged or inoperative NOTE If breather is integral part of valve cover and cannot be serviced separately replace valve cover and recheck pressure Disassemble breather clean parts thoroughly check sealing surfaces for flatness reassemble and recheck pressure Seals and or gaskets leaking Loose or improperly torque Replace all worn or damaged seals and gaskets Make fasteners sure all fasteners are tightened securely Use appropriate torque valves and sequences when necessary Piston blow by or leaky valves confirm by inspecting Recondition piston rings cylinder bore valves and components valves guides Restricted exhaust Check exhaust screen spark arrestor if equipped Clean or replace as needed Repair or replace any other damaged restricted muffler or exhaust system parts 32 690 03 Rev KohlerEngines com 17 Troubleshooting COMPRESSION TEST For Command Twins A compression test is best performed on a warm engine Clean any dirt or debris away fr
22. removed before engine is assembled and placed into operation Even small amounts of these cleaners can quickly break down lubricating properties of engine oil Check oil pan crankcase cylinder heads and valve covers to be certain all old sealing material has been removed Use gasket remover lacquer thinner or paint remover to remove any remaining traces Clean surfaces with isopropyl alcohol acetone lacquer thinner or electrical contact cleaner Connecting Rods Piston Breather Components BF Piston Ring Set Connecting Rod Connecting Rod F CESSES Piston Pin Retainer d Breather Cover Breather Hose Breather Filter Oil Seal 32 690 03 Rev Reassembly Install Flywheel End Oil Seal 1 Make sure seal bore of crankcase is clean and free of any nicks or burrs 2 Apply a light coat of engine oil to outside diameter of oil seal 3 Install oil seal into crankcase using a seal driver Make sure oil seal is installed straight and true in bore and tool bottoms against crankcase Install Breather Filter and Breather Cover Fastener Torque Sequence and Sealant A Sealant Bead NOTE Always use fresh sealant Using outdated sealant can result in leakage Refer to Tools and Aids for a listing of approved sealants NOTE To ensure proper adhesion of sealant to both sealing surfaces perform step 4 immediately 5 minutes maximum after application of RTV
23. retainer and washer from governor cross shaft 2 Remove cross shaft with small inner washer through inside of crankcase 3 Remove governor shaft seal from crankcase If governor cross shaft seal is damaged and or leaks replace it using following procedure Remove oil seal from crankcase and replace it with a new one Install new seal to depth shown 32 690 03 Rev Disassembly Inspection and Service Connecting Rods Piston Breather Components A Piston Ring Set B Piston Pin Retainer C Piston D Pistonem Connecting Rod E Connecting Rod I End Cap Breather Oil Seal Remove Breather Assembly Breather system is designed to control amount of oil in head area and still maintain necessary vacuum in crankcase When pistons move downward crankcase gases are pushed past reed through breather filter into intake system Upward travel of pistons closes reed and creates a low vacuum in lower crankcase Any oil separated out through filter drains back into crankcase 1 Remove screws securing breather cover to crankcase 2 Carefully remove cover and breather filter Make sure drain back hole is not plugged or restricted Remove Connecting Rods with Pistons and Rings NOTE If a carbon ridge is present at top of either cylinder bore use a ridge reamer tool to remove it before attempting to remove piston NOTE Cylinders are numbered on crankc
24. secondary air cleaned and reinstalled If inspection of system reveals valve Air is then drawn into exhaust manifold and any damage or decomposition of hoses secondary air muffler where it mixes with any unburned hydrocarbons valve or exhaust system parts should be replaced which then burn in heat of muffler A hose is connected between a carburetor port and a diaphragm chamber in secondary air valve Carburetor vacuum moves diaphragm to close valve when air induction is not reguired primary idle 32 690 03 Rev KohlerEngines com 43 Emission Compliant Systems Remove Inlet Screen Inlet Components Remove inlet screen from secondary air valve assembly by grasping inlet screen at base and gently pulling away from valve assembly 2 Use a soft brush to remove debris from screen 3 Run water through inlet screen in reverse direction 4 To reinstall push inlet screen onto barb of secondary air valve assembly An audible click will be heard when inlet screen is properly reinstalled 44 KohlerEngines com 32 690 03 Rev Disassembly Inspection and Service Accidental Starts can cause severe injury or Before working on engine or equipment disable engine as death follows 1 Disconnect spark plug lead s 2 Disconnect Disconnect and ground spark plug lead s negative battery cable from battery before servicing External Engine Components 777 SSL SSS DEF LEE 4 Yj 7 j n A gt gt I P
25. stator Most engines are equipped with a 12 15 amp regulated charging system Some have a 25 amp regulated charging system 12 15 25 Amp Regulated Charging System Stator Stator is mounted on crankcase behind flywheel Follow procedures in Disassembly and Reassembly if stator replacement is necessary Rectifier Regulator NOTE When installing rectifier regulator take note of terminal positions and install plug correctly NOTE Disconnect all electrical connections attached to rectifier regulator Testing may be performed with rectifier regulator mounted or loose Repeat applicable test procedure 2 or 3 times to determine condition of part Rectifier regulator is mounted on backing shroud assembly To replace it disconnect plug remove mounting screws and ground lead Testing rectifier regulator may be performed as follows using appropriate rectifier regulator tester To test 25 amp rectifier regulators To test 12 15 amp rectifier regulators 1 Connect single lead adapter in between B center 1 Connect tester ground lead with spring clamp to terminal of rectifier regulator being tested and body of rectifier regulator being tested squared single end of tandem adapter lead 2 Connect tester red lead to B terminal of rectifier 2 Connect tester ground lead with spring clamp to regulator and 2 black tester leads to 2 AC terminals body of rectifier regulator 3 Plug tester into proper AC outlet power for tester 3 Connect red
26. 010 0 0026 in and middle compression ring to groove side clearance 0 030 0 070 mm 0 0010 0 026 in If side clearance is greater than specified a new piston must be used 32 690 03 Rev Install New Piston Rings NOTE Rings must be installed correctly Ring installation instructions are usually included with new ring sets Follow instructions carefully Use a piston ring expander to install rings Install bottom oil control ring first and top compression ring last To install new piston rings proceed as follows 1 Oil control ring bottom groove Install expander and then rails Make sure ends of expander are not overlapped 2 Middle compression ring center groove Install center ring using a piston ring expander tool Make sure identification mark is up or colored dye stripe if contained is to left of end gap 3 Top compression ring top groove Install top ring using a piston ring expander tool Make sure identification mark is up or colored dye stripe if contained is left of end gap Remove Crankshaft Carefully pull crankshaft from crankcase Inspection and Service Inspect gear teeth of crankshaft If teeth are badly worn chipped or some are missing replacement of crankshaft will be necessary Inspect crankshaft bearing surfaces for scoring grooving etc Measure running clearance between crankshaft journals and their respective bearing bores Use an inside micrometer or telescoping gauge to me
27. 038 mm 0 7889 in Bearing Surface O D New 19 948 19 960 mm 0 7854 0 7858 in Max Wear Limit 19 945 mm 0 7852 in Connecting Rod Connecting Rod to Crankpin Running Clearance New 0 037 0 083 mm 0 0015 0 0033 in Max Wear Limit 0 098 mm 0 0039 in Connecting Rod to Crankpin Side Clearance 0 261 0 67 mm 0 0102 0 0264 in Connecting Rod to Piston Pin Running Clearance 0 013 0 032 mm 0 0005 0 0013 in Piston Pin End l D New 17 013 17 027 mm 0 6698 0 6704 in Max Wear Limit 17 040 mm 0 6709 in Crankcase Governor Cross Shaft Bore I D New 8 025 8 075 mm 0 3159 0 31 79 in Max Wear Limit 8 088 mm 0 3184 in Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 8 KohlerEngines com 32 690 03 Rev Specifications CLEARANCE SPECIFICATIONS KT715 KT725 KT730 KT735 KT740 KT745 Crankshaft End Play free 0 075 0 595 mm 0 0030 0 0023 in Bore in crankcase New 40 974 40 987 mm 1 6131 1 6137 in Max Wear Limit 41 000 mm 1 6142 in Bore in oil pan New 40 974 41 000 mm 1 6457 1 6142 in Crankshaft Bore in oil pan to Crankshaft Running Clearance New 0 039 0 087 mm 0 0015 0 0034 in Flywheel End Main Bearing Journal O D New 40 913 40 935 mm 1 6107 1 6116 in O D Max Wear Limit 40 840 mm 1 608 in Max Taper 0 022 mm 0 0009 in Max Out of Round 0 025 mm 0 0010 in Oil Pan End Ma
28. 1 20 S and 25 761 41 S Design Technology Inc CS PRO Regulator Test Harness DTI 031 Special Regulator Test Harness with Diode DTI 033 Spark Advance Module SAM Tester Kohler 25 761 40 5 For testing SAM ASAM and DSAM on engines with SMART SPARK Starter Servicing Kit All Starters SE Tools KLR 82411 For removing and reinstalling drive retaining rings and brushes Individual component available Starter Brush Holding Tool Solenoid Shift SE Tools KLR 82416 Triad OHC Timing Tool Set Kohler 28 761 01 S For holding cam gears and crankshaft in timed position while installing timing belt Valve Guide Reamer K and M Series Design Technology Inc For properly sizing valve guides after installation DTI K828 Valve Guide Reamer O S Command Series Kohler 25 455 12 S For reaming worn valve guides to accept replacement oversize valves Can be used in low speed drill press or with handle below for hand reaming Reamer Handle Design Technology Inc For hand reaming using Kohler 25 455 12 S reamer DTI K830 Valve Guide Service Kit Courage Aegis Command OHC SE Tools KLR 82415 For servicing worn valve guides AIDS Description Source Part No RTV Silicone Sealant Loctite 5900 Heavy Body in 4 oz aerosol dispenser Kohler 25 597 07 S Only oxime based oil resistant RTV sealants such as those listed are approved Loctite 59109 for use Loctite Nos 5900 or 5910 are recommended for best sealing Loctite Ultra Black 598 ch
29. 10 000 en ENGINE MOUNTING HOLE A TARTER STUD SURFACE PTO END SERE B76 jd 157 3 45 tcm er NM ME j aje ENGINE TING SURFACES a m 17 inc di EARNER Sra SURFACE B CARBURETOR SIDE 392 1 355 1 15 44 AT a PRO AIR k CLEANER comm CLEANER REMOVAL VLC Teal REMOVAL Ne 93944 3281 ue 13 94 m TOP OF PRO pisa gt AIR CLEANER AR CLEANER Li J u UAE 7 AR PLUG gn o uw AL a W a Bm E um 39 o MOUNTING MOUNTING aa SURFACE SURFACE ire PE FILTER MOUNTING SURFACE OIL FILTER SIDE 32 690 03 Rev KohlerEngines com 5 Specifications ENGINE IDENTIFICATION NUMBERS Kohler engine identification numbers model specification and serial should be referenced for efficient repair ordering correct parts and engine replacement 7000 Series Engine Numerical Designation Specification KT715 0001 Serial P 4323500328 Year Manufactured Code 2 Factory Code Year 2013 2014 2015 GENERAL SPECIFICATIONS KT715 KT725 KT730 KT735 KT740 KT745 83 mm 3 27 in MEERE 2721m Displacement 725 cc 44 cu in on Oil Capacity refill 1 91 2 0 at Maximum Angle of Operation full oil level TORQUE SPECIFICATIONS KT715 KT725 KT730 KT735 KT740 KT745 Baffle and Sheet Metal into Aluminum M5 Thread Forming Fasteners 8 5 N m 75 in Ib into new hole 4 0 N m 35 in Ib into used hole M6 Thread Formin
30. 60 mm 0 2819 in is maximum allowed on exhaust guide 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 guides are within limits but valve stems are worn beyond limits install new valves Valve Seat Inserts Hardened steel alloy intake and exhaust valve seat inserts are press fitted into cylinder head Inserts are not replaceable but can be reconditioned if not too badly pitted or distorted If cracked or badly warped cylinder head should be replaced Recondition valve seat inserts following instructions provided with valve seat cutter being used Final cut should be made with an 89 cutter as specified for valve seat angle Cutting proper 45 valve face angle as specified and proper valve seat angle 44 5 half of full 89 angle will achieve desired 0 5 1 0 full cut interference angle where maximum pressure occurs on outside diameters of valve face and seat Lapping Valves NOTE Exhaust valves that are black in color cannot be ground and do not require lapping 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 smooth surface is obtained on seat and on valve face Thoroughly clean cylinder head in soap and hot water to remove all traces of grindi
31. 600 RPM measure AC voltage across stator leads using an AC voltmeter Condition Conclusion Voltage is 28 volts or Stator is OK Rectifier more regulator is faulty replace ae is less than 28 Stator is faulty replace volts Test stator further using an ohmmeter steps 3 and 4 3 With engine stopped measure resistance across stator leads using an ohmmeter Condition Conclusion Resistance is 0 064 0 2 Stator is OK ohms Resistance is 0 ohms Stator is shorted replace Resistance is infinity Stator is open replace ohms 4 With engine stopped measure resistance from each stator lead to ground using an ohmmeter Condition Conclusion on is infinity ohms Stator is OK not shorted no continuity to ground Resistance or continuity Stator leads are shorted to measured ground replace 32 690 03 Rev KohlerEngines com 35 Starter System NOTE Do not crank engine continuously for more than 10 seconds Allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn out starter motor NOTE If engine develops sufficient speed to disengage starter but does not keep running a false start engine rotation must be allowed to come to a complete stop before attempting to restart engine If starter is engaged while flywheel is rotating starter pinion and flywheel ring gear may clash and damage starter NOTE If starter does not crank engine shut off starte
32. 8 N m 25 in Ib BREATHER TUBE Ensure both ends of breather tube are properly connected AIR COOLING wARNING zh Hot Parts can cause severe burns n Do not touch engine while operating or just after stopping Never operate engine with heat shields or guards removed Proper cooling is essential To prevent over heating clean screens cooling fins and other external surfaces of engine Avoid spraying water at wiring harness or any electrical components Refer to Maintenance Schedule KohlerEngines com 19 Fuel System Typical carbureted fuel system and related components include e Fuel tank e Fuel lines e In line fuel filter e Fuel pump e Carburetor Fuel from tank is moved through in line filter and fuel lines by fuel pump Fuel then enters carburetor float bowl and is drawn into carburetor body and mixed with air This fuel air mixture is then burned in engine combustion chamber Performance Minimum fuel delivery rate must be 7 5 l hr 2 gal hr with a pressure at 0 3 psi and a fuel lift of 24 in A 1 3 hr 0 34 gal hr fuel rate must be maintained at 5 Hz Fuel Pump Replacement NOTE Make sure orientation of new pump is consistent with removed pump Internal damage may occur if installed incorrectly To replace pulse pump follow these steps Note orientation of pump before removing FUEL RECOMMENDATIONS jm Disconnect fuel lines from inlet outlet and pulse Refer to Maintenan
33. A typical fixed ignition system consists of e 1 magnet assembly which is permanently affixed to flywheel e 2 electronic capacitive discharge or magnetic discharge ignition modules which mount on engine crankcase e 1 kill switch or key switch which grounds modules to stop engine e 2 spark plugs Wiring Diagram Electronic Ignition System Diagram u Solenoid Shift Inertia Driver E Violet Charging F Oil Sentry Optional B Spark Plug s n AC Charging Leads Rectifier Regulator Flywheel Stator Ba Rectifier Regulator K Assembly S Ignition Module s M Intake Manic Screw Intake Manifold Screw tt er Lr White Ignition Kill SEE ST one E Cone Relay ee y Battery Negative Battery Fr Battery Positive rag c Orange shown se vme Sera ae meten AF Pony ne Solenoid Shift Starter Assembly Optional KohlerEngines com 32 690 03 Rev Electrical System Electronic Ignition Systems Tests NOTE Ignition tester must be used to test ignition on these engines Use of any other tester can result in inaccurate findings Battery on unit must be fully charged and properly connected before performing tests a battery that is hooked up or charged backward will crank engine but it won t have spark Be certain drive is in neutral and all external loads are disconnected Test Ignition Systems NOTE If engine starts or runs during testing you may need to ground
34. CAUTION al Electrical Shock can cause injury y Do not touch wires while engine is running Spark Plug Component and Details A WireGauge B SparkPlug Ground Electrode D 4 Gap NOTE Do not clean spark plug in a machine using abrasive grit Some grit could remain in spark plug and enter engine causing extensive wear and damage Engine misfire or starting problems are often caused by a spark plug that has improper gap or is in poor condition Engine is equipped with following spark plugs 0 76 mm 0 03 in Thread Size 19 1 mm 3 4 in 15 9 mm 5 8 in Refer to Maintenance for Repairs Service Parts Service Clean out spark plug recess Remove plug and replace 1 Check gap using wire feeler gauge Adjust gap to 0 76 mm 0 03 in 2 Install plug into cylinder head 3 Torque plug to 27 N m 20 ft Ib 30 KohlerEngines com Inspection Inspect each spark plug as it is removed from cylinder head Deposits on tip are an indication of general condition of piston rings valves and carburetor Normal and fouled plugs are shown in following photos Normal Plug taken from an engine operating under normal conditions will have light tan or gray colored deposits If center electrode is not worn plug can be set to proper gap and reused Worn On a worn plug center electrode will be rounded and gap will be greater than specified gap Replace a worn spark plug immediat
35. Debris Screen Snap screen onto fan Install Blower Housing NOTE Do not completely tighten screws until all are installed to allow shifting for hole alignment 1 Install blower housing onto engine Start all mounting screws Make sure wire harness and spark plug leads exit out through appropriate openings in shrouding Attach any fuel line clamps used 32 690 03 Rev 2 Torque screws as follows M5 Blower Housing Screws 6 2 N m 55 in Ib ina new hole or 4 0 N m 35 in Ib in a used hole M4 HI LO Screws 2 8 N m 25 in Ib M3 HI LO Screws 2 3 N m 20 in Ib Install Fixed Guard if equipped Install fixed guard Securely tighten screw if equipped Install Dipstick Tube 1 Lubricate dipstick tube O ring and install into crankcase 2 Secure to backing plate using M5 screw 3 Torque screw to 4 0 N m 35 in Ib Install Fuel Pump Avana Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running 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 Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent Fuel Pump Components Reassembly 1 Connect pulse hose to valve cover Valve cover should be situated between 2 formed lips on pulse
36. KOHLER 000 Series KT715 KT745 Service Manual ee s WU uuu PUL ut IMPORTANT Read all safety precautions and instructions carefully before operating equipment Refer to operating instruction of equipment that this engine powers Ensure engine is stopped and level before performing any maintenance or service 2 Safety 3 Maintenance 5 Specifications 12 Tools and Aids 15 Troubleshooting 19 Aq Air Cleaner Intake 20 Fuel System 27 Governor System 28 Lubrication System 30 Electrical System 36 Starter System 42 Emission Compliant Systems 45 Disassembly Inspection and Service 57 Reassembly 32 690 03 Rev Safety SAFETY PRECAUTIONS A WARNING A hazard that could result in death serious injury or substantial property damage A CAUTION A hazard that could result in minor personal injury or property damage NOTE is used to notify people of important installation operation or maintenance information Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running 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 Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent Rotating Parts can cause Stay away while engine is in operation
37. RTERS Inertia Drive Electric Starter Components Commutator End Cap with Brushes C Armature D When power is applied to starter armature rotates As armature rotates drive pinion moves out on drive shaft splines and into mesh with flywheel ring gear When pinion reaches end of drive shaft it rotates flywheel and cranks engine When engine starts flywheel rotates faster than starter armature and drive pinion This moves drive pinion out of mesh with ring gear and into retracted position When power is removed from starter armature stops rotating and drive pinion is held in retracted position by anti drift spring 32 690 03 Rev E Drive Nut Collar F Drive Pinion G Anti Drift Spring H SpringRetainer I Retaining Ring J DustCovr Starter System Drive Service If drive pinion is worn or has chipped or broken teeth it must be replaced 1 Rubber dust cover has a molded lip on inside that snaps over a lip on front of drive pinion Turn drive pinion clockwise until it reaches fully extended position While holding it in extended position grasp tip of dust cover with a pliers or vise grip and pull it free from pinion Grasp spring retainer with a pliers and push it toward starter compressing anti drift spring to expose retaining ring Remove retaining ring from armature shaft using either a retaining ring pliers or snap ring removal tool as described in Steps 4 and 5 Do n
38. Wear Limit Length Inspect both springs and brushes for wear fatigue or damage Measure length of each brush Minimum length for each brush is 7 6 mm 0 300 in Replace brushes if they are worn undersize or condition is questionable 32 690 03 Rev Starter System Armature Components and Details A CommutatorO D B Mica Insulation Insulation Check D Armature Coil E Continuity Check 1 Clean and inspect commutator outer surface Mica insulation must be lower than commutator bars undercut to ensure proper operation of commutator 2 Use an ohmmeter set to Rx1 scale Touch probes between 2 different segments of commutator and check for continuity Test all segments Continuity must exist between all or armature is bad 3 Check for continuity between armature coil segments and commutator segments There should be no continuity If continuity exists between any 2 armature is bad 4 Check armature windings insulation for shorting Shift Fork Check that shift fork is complete and pivot and contact areas are not excessively worn cracked or broken Brush Replacement 4 brushes and springs are serviced as a set Use a new Kohler brush and spring kit if replacement is necessary 1 Perform steps 1 5 in Starter Disassembly 2 Remove screws securing brush holder assembly to end cap plate Note orientation for reassembly later Discard old brush holder assembly 3 Clean component part
39. actice to drain oil at a location away from workbench Be sure to allow ample time for complete drainage Before cleaning or disassembling engine make a thorough inspection of its external appearance and condition This inspection can give clues to what might be found inside engines and cause when it is disassembled e Check for buildup of dirt and debris on crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas can cause overheating e Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or inoperative breather worn or damaged seals or gaskets or loose fasteners e Check air cleaner cover and base for damage or indications of improper fit and seal e Check air cleaner element Look for holes tears cracked or damaged sealing surfaces or other damage that could allow unfiltered air into engine A dirty or clogged element could indicate insufficient or improper maintenance e Check carburetor throat for dirt Dirt in throat is further indication that air cleaner was not functioning properly e Check if oil level is within operating range on dipstick If it is above sniff for gasoline odor e Check condition of oil Drain oil into a container it 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 indicat
40. add oil to gasoline e Do not overfill fuel tank e Do not use gasoline older than 30 days KohlerEngines com STORAGE If engine will be out of service for 2 months or more follow procedure below 1 Add Kohler PRO Series fuel treatment or equivalent to fuel tank Run engine 2 3 minutes to get stabilized fuel into fuel system failures due to untreated fuel are not warrantable 2 Change oil while engine is still warm from operation Remove spark plug s and pour about 1 oz of engine oil into cylinder s Replace spark plug s and crank engine slowly to distribute oil 3 Disconnect negative battery cable 4 Store engine in a clean dry place 32 690 03 Rev Specifications Engine Dimensions Dimensions in millimeters Inch equivalents shown in 334 3 13 38 728 72 8 54 3 2 87 2 ar 3 71 Ja 1 Fr EVA ee 1 89 7 PON r 4 5116 18 UNC 2B y 165 NO STUDS Pi ano 30 i ii AD S 30 EXHAUST y e PORTH 4230 s v1 15 65 if E SD M j 4 10 58 312 0 y 12 28 104 0 HROTTLE 14 10 AND CHOKE e An 1 Kl pus CABLE IG 9 53 I Ir Wigs SURFACE 13 57 353 p 2 m a 5 38 50 1 197 E en E DIPSTICK 7 j 10 54 IL FILTER YELLOW es r i Ax e ne 74100 d u ar REMOVAL FUEL LINE S x 212 31814 Be CONNECTION 3 53 i m 3 54 ini 4 60 00 A C n o iced mim TOP VIEW
41. ake Manifold Torque Sequence 1 Install intake manifold using new O rings with wiring harness attached onto cylinder heads Slide any wiring harness clips onto appropriate bolts before installing Using sequence shown torque screws in 2 increments first to 7 4 N m 66 in Ib then to 9 9 N m 88 in Ib 2 Connectkill lead to tab terminal on standard ignition modules 32 690 03 Rev Reassembly Install Rectifier Regulator if equipped 1 Install B terminal lead into center position of rectifier regulator plug so it locks in place and connect plug to rectifier regulator 2 Attach rectifier regulator to opening in backing plate from underside and secure with mounting screws Torque screws to 4 0 N m 35 in Ib Install Inner and Outer Cylinder Baffles 1 Attach outer cylinder baffles and secure with M6 screw lower cylinder location and M5 screw into backing plate Tighten screws as listed following step 2 2 Attach inner baffles including any lifting straps to cylinder head flanges and to 2 crankcase mounting bosses Lift strap should be outside outer baffle Secure with M5 screws Remaining lower inner baffle mounting screws will be installed later Torque baffle mounting screws M5 screws 6 2 N m 55 in Ib into a new cored hole or 4 0 N m 35 in Ib into a used hole M6 screws 10 7 N m 95 in Ib into a new cored hole or 7 3 N m 65 in Ib into a used hole Install C
42. ankcase 3 Apply a 1 5 mm 1 16 in bead of black RTV sealant to sealing surface of oil pan See sealant pattern Oil pan must be installed within 5 minutes of sealant being applied for proper sealing to occur 4 Make sure end of governor cross shaft is lying against bottom of cylinder inside crankcase 5 Install oil pan to crankcase Carefully seat camshaft with shim and crankshaft into their mating bearings Rotate crankshaft to help engage oil pump and governor gear meshes 6 Install 10 screws securing oil pan to crankcase Torque fasteners in sequence shown to 24 4 N m 216 in Ib Bp fan D Fan Mounting Plate CF Fe G Stator H Backing Plate 1 Breather Reed Cover J Stud LK Retainer L Breather Reed M Fiywhest Key 60 KohlerEngines com 32 690 03 Rev Install Breather Reed and Breather Reed Cover Breather Reed Cover Sealant Sealant Bead NOTE RTV sealant should be allowed to cure a minimum of 1 hour before engine is started 1 Install breather reed followed by retainer over passage hole and mounting hole in crankcase Hold in position and secure with mounting stud Torque stud to 6 2 N m 55 in Ib into a new cored hole or 4 0 N m 35 in Ib into a used hole 2 Invert breather reed cover and apply a 1 5 mm 1 16 in bead of RTV sealant to perimeter flange of cover as shown Use
43. apter Pressure switch is designed to break contact as oil pressure increases above 3 5 psi and make contact as oil pressure decreases below 3 5 psi On stationary or unattended applications pumps generators etc pressure switch can be used to ground Ignition module to stop engine On vehicular applications lawn tractors mowers etc pressure switch can only be used to activate a low oil warning light or signal 32 690 03 Rev Lubrication System Installation 1 Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads of switch 2 Install switch into tapped hole in oil filter adapter 3 Torque switch to 4 5 N m 40 in Ib Testing Compressed air a pressure regulator pressure gauge and a continuity tester are required to test switch 1 Connect continuity tester across blade terminal and metal case of switch With O psi pressure applied to switch tester should indicate continuity switch closed 2 Gradually increase pressure to switch As pressure increases through range of 2 5 psi tester should indicate a change to no continuity switch open Switch should remain open as pressure is increased to 90 psi maximum 3 Gradually decrease pressure through range of 2 5 psi Tester should indicate a change to continuity switch closed down to 0 psi 4 Replace switch if it does not operate as specified KohlerEngines com 29 Electrical System SPARK PLUGS A
44. aracteristics Loctite Ultra Blue 587 Loctite Ultra Copper 5920 Spline Drive Lubricant Kohler 25 357 12 S 32 690 03 Rev KohlerEngines com 13 Tools and Aids FLYWHEEL HOLDING TOOL A flywheel holding tool can be made out of an old junk flywheel ring gear and used in place of a strap wrench 1 Using an abrasive cut off wheel cut out a six tooth segment of ring gear as shown 2 Grind off any burrs or sharp edges 3 Invert segment and place it between ignition bosses on crankcase so tool teeth engage flywheel ring gear teeth Bosses will lock tool and flywheel in position for loosening tightening or removing with a puller ROCKER ARM CRANKSHAFT TOOL A spanner wrench to lift rocker arms or turn crankshaft may be made out of an old junk connecting rod 1 Find a used connecting rod from a 10 HP or larger engine Remove and discard rod cap 2 Remove studs of a Posi Lock rod or grind off aligning steps of a Command rod so joint surface is flat 3 Finda 1 in long capscrew with correct thread size to match threads in connecting rod 4 Use aflat washer with correct I D to slip on capscrew and approximately 1 in O D Assemble capscrew and washer to joint surface of rod 14 KohlerEngines com 32 690 03 Rev TROUBLESHOOTING GUIDE Troubleshooting When troubles occur be sure to check simple causes which at first may seem too obvious to be considered For example a starting problem could
45. arance 0 006 0 017 mm 0 0002 0 0007 in Pin Bore I D New 17 006 17 012 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in 16 995 17 000 mm 0 6691 0 6693 in Max Wear Limit 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance 0 030 0 070 mm 0 001 0 0026 in Middle Compression Ring to Groove Side Clearance 0 030 0 070 mm 0 001 0 0026 in Oil Control Ring to Groove Side Clearance 0 060 0 190 mm 0 0022 0 0073 in Top Compression Ring End Gap New Bore 0 189 0 277 mm 0 0074 0 0109 in Used Bore Max 0 531 mm 0 0209 in Middle Compression Ring End Gap New Bore 1 519 1 797 mm 0 0598 0 0708 in Used Bore Max 2 051 mm 0 0808 in Thrust Face O D New 82 978 mm 3 2668 in Max Wear Limit 82 833 mm 3 2611 in Piston Thrust Face to Cylinder Bore Running Clearance New 0 019 0 062 mm 0 0007 0 0024 in Valves and Valve Tappets Exhaust Valve Stem to Valve Guide Running Clearance Intake Valve Guide I D New 7 040 7 060 mm 0 2772 0 2780 in Max Wear Limit 7 140 mm 0 2811 in Exhaust Valve Guide l D New 7 040 7 060 mm 0 2772 0 2780 in Max Wear Limit 7 160 mm 0 2819 in Valve Guide Reamer Size Standard 7 050 mm 0 2776 in 0 25 mm O S 7 300 mm 0 2874 in Intake Valve Minimum Lift 8 500 mm 0 3346 in Exhaust Valve Minimum Lift 8 500 mm 0 3346 in Nominal Valve Face Angle Values are in Metric units Values in parentheses are English equiva
46. arburetor Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running 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 Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent Install a new carburetor gasket Make sure all holes align and are open 2 Install carburetor throttle linkage and governor lever as an assembly 3 If carburetor is equipped with a fuel solenoid connect red power lead Attach eyelet terminal of ground lead to inner top carburetor cover mounting screw KohlerEngines com 65 Reassembly Install External Governor Controls Control Bracket Components aa DEI TUR C Governor Lever D Governor Spring E Cross Shaft F Control Bracket G Dampener Spring Throttle and Choke Components EET ao Throttle Actuator e meme o Mojo E Control Bracket F Choke Return Spring G Lock Nut M5x0 8 H Shoulder Washer _ 1 FlatWasher J NylonWasher L K Wave Washer _ Install governor lever onto governor cross shaft if disconnected previously 2 Make sure throttle linkage is connected to governor lever and throttle lever on carburetor Connect choke linkage to carburetor choke leve
47. ark plug lead s 2 Disconnect negative battery cable from battery NOTE Main and slow jets are fixed and size specific and can be removed if required Fixed jets for high altitudes are available e Inspect carburetor body for cracks holes and other wear or damage e Inspect float for cracks holes and missing or damaged float tabs Check float hinge and shaft for wear or damage e Inspect fuel inlet needle and seat for wear or damage e Inspect spring loaded choke plate to make sure it moves freely on shaft 32 690 03 Rev Fuel System Float Setting Keihin Only 12 mm 0 472 in Inlet needle center pin is spring loaded Make sure float assembly rests against fuel inlet needle without depressing center pin 1 Perform removal procedures for appropriate air cleaner and carburetor outlined in Disassembly 2 Clean exterior surfaces of dirt or foreign material before disassembling carburetor Remove bowl retaining screws or solenoid assembly and carefully separate fuel bowl from carburetor Do not damage fuel bowl O rings Transfer any remaining fuel into an approved container Save all parts 3 Remove float pin Some carburetors may have a screw which requires removal and inlet needle Seat for inlet needle is not serviceable and should not be removed 4 Remove two screws securing top cover gasket and
48. ase Use numbers to mark each end cap connecting rod and piston for reassembly Do not mix end caps and connecting rods 1 Remove screws securing closest connecting rod end cap Remove end cap 2 Carefully remove connecting rod and piston assembly from cylinder bore 3 Repeat above procedure for other connecting rod and piston assembly Connecting Rods Offset stepped cap connecting rods are used in all these engines KohlerEngines com 53 Disassembly Inspection and Service Inspection and Service Check bearing area big end for excessive wear score marks running and side clearances See Specifications Replace rod and cap if scored or excessively worn Service replacement connecting rods are available in STD size and 0 25 mm 0 010 in undersize Undersized rods 0 25 mm 0 010 in have an identification marking on lower end of rod shank Always refer to appropriate jse information to ensure correct replacements are used Piston and Rings Inspection Piston and Rings Components and Details A Piston Ring B End Gap Top Compression Middle Compression Ring Ring G Rails H Expander Scuffing and scoring of pistons and cylinder walls occurs when internal engine temperatures approach welding point of piston Temperatures high enough to do this are created by friction which is usually attributed to improper lubrication and or overheating of engine Normally very little wear takes place in piston bo
49. asure inside diameter of both bearing bores in vertical and horizontal planes Use an outside micrometer to measure outside diameter of crankshaft main bearing journals Subtract journal diameters from their respective bore diameters to get running clearances Check results against values in Specifications If running clearances are within specification and there is no evidence of scoring grooving etc no further reconditioning is necessary If bearing surfaces are worn or damaged crankcase and or oil pan will need to be replaced Inspect crankshaft keyways If worn or chipped replacement of crankshaft will be necessary Inspect crankpin for score marks or metallic pickup Slight score marks can be cleaned with crocus cloth soaked in oil If wear limits are exceeded as stated in Specifications it will be necessary to replace crankshaft Remove Flywheel and PTO End Oil Seals Remove oil seals from crankcase and oil pan Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments Gasket surfaces must also be free of deep scratches or nicks 32 690 03 Rev Disassembly Inspection and Service Check cylinder bore for scoring In severe cases unburned fuel can cause scuffing and scoring of cylinder wall It washes necessary lubricating oils off piston and cylinder wall As raw fuel seeps down cylinder wall piston rings make metal to metal contact with wall Scoring of cylinder wa
50. ated at factory and is not adjustable Idle fuel adjusting needles are also set at factory and are not adjustable a Speed RPM Adjustment Hold governor lever away from carburetor so throttle lever is against idle speed RPM adjustment screw of carburetor Start engine and allow to warm up then adjust screw to set approximately 1450 RPM Check speed using a tachometer Turn adjustment screw inner clockwise in to increase or counterclockwise out to decrease speed 2 Release governor lever and check that throttle lever Is in idle position Obtain eguipment manufacturer s recommended idle speed 1750 RPM All engines have a bendable tab that is used to set this speed A pliers should be used to bend this tab to achieve recommended speed Governed idle speed RPM is ae 300 RPM approximate higher than low idle speed 3 Move throttle lever to wide open full throttle position and hold in this position Turn high speed screw to obtain intended high speed no load RPM Governed idle speed must be set before making this adjustment High Speed RPM Adjustment 1 With engine running move throttle control to fast 2 Turn inner adjustment screw outward to decrease or inward to increase RPM speed Carburetor Servicing ees A WARNING Accidental Starts can cause severe injury or death Disconnect and ground spark plug lead s before servicing Before working on engine or equipment disable engine as follows 1 Disconnect sp
51. can occur Minimum allowable clearance is 0 25 mm sealant can result in leakage Refer to Tools and Aids for information on sealant dispenser NOTE To ensure proper adhesion of sealant to both sealing surfaces perform step 3 immediately 5 0 010 in Check Assembly Rotate crankshaft a minimum of 2 revolutions to check longblock assembly and overall proper operation minutes maximum after application of RTV RTV silicone sealant is used as a gasket between valve cover and cylinder head Refer to Tools and Aids for a listing of approved sealants 1 Prepare sealing surfaces of cylinder heads and valve covers Flatness of sealing surface must be checked prior to reinstallation See Disassembly 2 Apply a 1 5 mm 1 16 in bead of sealant to valve cover as shown 3 Position covers on cylinder heads If a pulse style fuel pump is used valve cover with pulse fitting hole must be installed on side 2 Install screws in each cover and finger tighten 4 Torque valve cover fasteners to 9 6 N m 85 in Ib using sequence shown 32 690 03 Rev KohlerEngines com 63 Reassembly Install Spark Plugs 1 Check gap using wire feeler gauge Adjust gap to 0 76 mm 0 03 in 2 Install plug into cylinder head 3 Torque plug to 27 N m 20 ft Ib External Engine Components E HoseClamp F FuelPump G HoseCip H Fuelline 1 FuelFilter J OilFil
52. ce fittings on fuel pump FUEL LINE 2 Remove screws and take off pump Connect pulse line to new fuel pump and make sure opposite end is properly connected into valve cover Attach new fuel pump using screws Torque screws to 2 8 N m 25 in Ib Reconnect fuel lines to inlet and outlet fittings and secure with clamps Low permeation fuel line must be installed on carbureted 3 Kohler Co engines to maintain EPA and CARB regulatory compliance 4 FUEL PUMP Some engines use a pulse style fuel pump Pumping o action of pulse style pumps is created by oscillation of positive and negative pressures within crankcase This pressure is transmitted to pulse pump through rubber hose connected between pump and crankcase Pumping action causes diaphragm on inside of pump to pull fuel in on its downward stroke and to push it into carburetor on its upward stroke Two check valves prevent fuel from going backward through pump FUEL SYSTEM TESTS When engine starts hard or turns over but will not start fuel system might be causing problems Test fuel system by performing following test 1 Check for fuel in combustion chamber a Disconnect and ground spark plug leads b Close choke on carburetor c Crank engine several times d Remove spark plug and check for fuel at tip 2 Check for fuel flow from tank to fuel pump a Remove fuel line from inlet fitting of fuel pump b Hold line below bottom of tank Open shut off valv
53. cure Remove feeler gauge which will have established proper endplay Install Crankshaft Lubricate flywheel side main bearing surface and lips of oil seal in crankcase with clean engine oil 2 Carefully slide flywheel end of crankshaft through main bearing in crankcase Install Connecting Rods with Pistons and Rings NOTE Cylinders are numbered on crankcase Make sure to install piston connecting rod and end cap into its appropriate cylinder bore as previously marked during disassembly Do not mix end caps and connecting rods NOTE Proper orientation of piston connecting rod assemblies inside engine is extremely important Improper orientation can cause extensive wear or damage Be certain pistons and connecting rods are assembled exactly as shown NOTE Align chamfer of connecting rod with chamfer of its mating end cap When installed flat faces of connecting rods should face each other Faces with raised rib should be toward outside Stagger piston rings in grooves until end gaps are 120 apart Oil ring rails should also be staggered Lubricate cylinder bore piston and piston rings with engine oil Compress rings using a piston ring compressor Lubricate crankshaft journals and connecting rod bearing surfaces with engine oil 58 KohlerEngines com 32 690 03 Rev 4 Make sure FLY stamping on piston is facing toward flywheel side of engine Use a hammer with a rubber or wood grip and gently tap pis