Kohler COMMAND CH18-745- User Manual

1.4 Section 1Safety and General Information Oil Recommendations Using the proper type and weight of oil in the crankcaseis extremely important. So is checking oil daily andchanging oil regularly. Failure to use the correct oil, orusing dirty oil, causes premature engine wear and failure. Oil Type Us...

1.5 Section 1 Safety and General Information 1 Periodic Maintenance Instructions WARNING: Accidental Starts! Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disc...

1.8 Section 1Safety and General Information General Specifications¹ Power (@ 3600 RPM, corrected to SAE J1995) CH18 ............................................................................................................................ 13.4 kW (18 HP)CH20 ..........................................

1.9 Section 1 Safety and General Information 1 Camshaft End Play (With Shim) .................................................................................. 0.076/0.127 mm (0.0030/0.0050 in.) Running Clearance ...................................................................................... ...

1.10 Section 1Safety and General Information Closure Plate Closure Plate Fastener Torque .............................................................. 24.4 N·m (216 in. lb.) Crankshaft End Play (Free) .................................................................................... 0.070/0.590 m...

1.11 Section 1 Safety and General Information 1 Cylinder Head Cylinder Head Fastener Torque Hex. Flange Nut - Torque in Two Stages .......................................... initially to 16.9 N·m (150 in. lb.) finally to 33.9 N·m (300 in. lb.) Head Bolt - Torque in Two Stages ..........................

1.12 Section 1Safety and General Information ²Measure 6 mm (0.236 in.) above the bottom of the piston skirt at right angles to the piston pin. Muffler Muffler Retaining Nut Torque .................................................................. 24.4 N·m (216 in. lb.) Oil Filter Oil Filter Torque ....

1.13 Section 1 Safety and General Information 1 Piston, Piston Rings, and Piston Pin cont. Piston Thrust Face-to-Cylinder Bore² Running Clearance New - CH18, CH20, CH22 (624 cc) ............................................... 0.014/0.057 mm (0.0005/0.0022 in.)New - CH22/23 (674 cc) ....................

1.14 Section 1Safety and General Information Valves and Valve Lifters cont. Exhaust Valve Guide I.D. New ................................................................................................ 7.038/7.058 mm (0.2771/0.2779 in.)Max. Wear Limit ...................................................

1.15 Section 1 Safety and General Information 1 English Fastener Torque Recommendations for Standard Applications Grade 2 or 5Fasteners IntoAluminum Size8-32 2.3 (20) 2.8 (25) --------- 2.3 (20) 10-24 3.6 (32) 4.5 (40) --------- 3.6 (32) 10-32 3.6 (32) 4.5 (40) --------- --------- 1/4-20 7.9 (70) 13...

2.1 Section 2 Special Tools 2 Section 2 Special Tools CH18-745 Certain quality tools are designed to help you perform specific disassembly, repair, and reassembly procedures.By using tools designed for the job, you can service engines easier, faster, and safer! In addition, you’ll increaseyour servi...

2.2 Section 2Special Tools Figure 2-1. Tool Catalog and Price List. Special Tools You Can Make Flywheel Holding Tool Flywheel removal and reinstallation becomes a “snap”using a handy holding tool which can be made out of anold “junk” flywheel ring gear as shown in Figure 2-2.Using an abrasive cut-of...

2.3 Section 2 Special Tools 2 Figure 2-5. Loctite ® 5900 Aerosol Dispenser. Camshaft Break-in Lubricant Camshaft lubricant, Kohler Part No. 25 357 14-S (Valspar ZZ613), should be used whenever a newcamshaft and lifters are installed for proper break-inupon initial startup. Lubricant is included with...

3.1 Section 3 Troubleshooting 3 Section 3 Troubleshooting Troubleshooting Guide When troubles occur, be sure to check the simplecauses which, at first, may seem too obvious to beconsidered. For example, a starting problem could becaused by an empty fuel tank. Some general common causes of engine tro...

3.2 Section 3Troubleshooting Engine Will Not Idle 1. Dirt or water in the fuel system.2. Stale fuel and/or gum in carburetor.3. Faulty spark plugs.4. Fuel supply inadequate.5. Idle speed adjusting screw improperly set.6. Idle fuel adjusting needle improperly set (some models). 7. Low compression.8. ...

3.3 Section 3 Troubleshooting 3 • Check the condition of the oil. Drain the oil into acontainer - the oil should flow freely. Check formetal chips and other foreign particles. Sludge is a natural by-product of combustion; asmall accumulation is normal. Excessive sludgeformation could indicate overri...

3.5 Section 3 Troubleshooting 3 Leakdown Test Results Air escaping from crankcase breather ................................................... Defective rings or worn cylinder.Air escaping from exhaust system ......................................................... Defective exhaust valve.Air escap...

4.1 Section 4 Air Cleaner and Air Intake System 4 Section 4 Air Cleaner and Air Intake System Air Cleaners General Most engines are equipped with a replaceable, high-density paper air cleaner element, surrounded by anoiled foam precleaner, and housed under a flat outercover. This is typically referr...

4.3 Section 4 Air Cleaner and Air Intake System 4 5. Check the seal for any damage or deterioration. Replace as necessary. See Figure 4-7. 6. Reinstall the seal, paper element, precleaner, element cover, and wing nut. 7. Reinstall the air cleaner cover and secure with the latches or the retaining kn...

4.4 Section 4Air Cleaner and Air Intake System Figure 4-9. Bracket Retaining Screw. Air Cleaner Element Cover and Seal - Make sure element cover is not bent or damaged. Make sure thewing nut and seal are in place to ensure the element issealed against leakage. Air Cleaner Base - Make sure the base i...

4.5 Section 4 Air Cleaner and Air Intake System 4 Figure 4-12. Heavy-Duty Air Cleaner. To Service Every 250 hours of operation (more often under extremely dusty or dirty conditions), replace thepaper element and check the inner element. Followthese steps. 1. Unhook the two retaining clips and remove...

4.6 Section 4Air Cleaner and Air Intake System Figure 4-14. Adapters for Heavy-Duty Air Cleaners. Air Intake/Cooling System To ensure proper cooling, make sure the grass screen,cooling fan fins, and external surfaces of the engineare kept clean at all times . Every 100 hours of operation (more often...

5.1 Section 5 Fuel System and Governor 5 Section 5 Fuel System and Governor Description The Command horizontal twins use three differenttypes of fuel systems; carbureted, electronic fuelinjection (EFI), or gaseous. Gaseous fuel systems canbe either liquefied petroleum gas (LPG or LP) ornatural gas (...

5.2 Section 5Fuel System and Governor Gasoline/Ether blends Methyl Tertiary Butyl Ether (MTBE) and unleadedgasoline blends (up to a maximum of 15% MTBE byvolume) are approved as a fuel for Kohler engines.Other gasoline/ether blends are not approved. Troubleshooting – Fuel System Related Causes Fuel ...

5.3 Section 5 Fuel System and Governor 5 NOTE: On most models, the pulse line is connected to a fitting on the crankcase,while on early models, it is connected tothe valve cover. 4. Install the new fuel pump using the hex. flange screws. Torque the hex. flange screws to 2.3 N·m (20 in. lb.) . NOTE: ...

5.4 Section 5Fuel System and Governor Carburetor General These engines are equipped with fixed main jetcarburetors manufactured by Keihin to Kohlerspecifications. Most have automatic chokes and fuelshut-off solenoids. Keihin carburetors with acceleratorpump features are standard on many models, and ...

5.5 Section 5 Fuel System and Governor 5 Troubleshooting Checklist When the engine starts hard, runs roughly or stalls atlow idle speed, check the following areas beforeadjusting or disassembling the carburetor. • Make sure the fuel tank is filled with clean, freshgasoline. • Make sure the fuel tank...

5.6 Section 5Fuel System and Governor Figure 5-4. Pre-Compliance Carburetor with LowIdle Adjustment. 1. With the engine stopped , turn the low idle fuel adjusting needle in clockwise until it bottoms lightly . NOTE: The tip of the idle fuel adjusting needle is tapered to critical dimensions. Damaget...

5.7 Section 5 Fuel System and Governor 5 Figure 5-6. Carburetor Detail. 5. Hold the carburetor upper body so that the float assembly hangs vertically and rests lightly againstthe fuel inlet needle. The fuel inlet needle shouldbe fully seated, but the needle tip should not bedepressed. See Figure 5-7...

5.9 Section 5 Fuel System and Governor 5 1. Carburetor Upper Body (Choke)2. Self-relieving Choke3. Body Gasket (Formed Rubber)4. Slow Speed Jet5. Inlet Needle Valve6. Clip7. Float Pin8. Float Assembly (Kit)9. Carburetor Lower Body (Throttle) 10. Main Jet 11. Idle Fuel Adjusting Needle (some models) ...

5.10 Section 5Fuel System and Governor Reassembly Reassemble the carburetor using the following steps.See Figure 5-9. 1. Assemble the fuel inlet needle to the float tab. Install the float, float shaft and inlet needle to theair horn. Tighten the screw. Check float heightusing the procedure found pre...

5.12 Section 5Fuel System and Governor Figure 5-13. Electronic Governor Assembly. Digital Linear Actuator (DLA) Energizing the bi-directional digital linear actuator coilsin the proper sequence, causes the threaded shaft tomove out of, or back into the rotor, in precise linearincrements. When power ...

5.13 Section 5 Fuel System and Governor 5 Governor Control Unit (GCU) senses engine speed bypulse voltage inputs from the ignition modules. TheGCU regulates the engine speed by variable inputvoltage from a customer-supplied potentiometer or asingle pole, single throw (SPST) switch. Potentiometer Spe...

5A.1 Section 5A LPG Fuel Systems 5A Section 5A LPG Fuel Systems CH18-740 Figure 5A-1. Vacuum Line Vaporizer Lock-Off/FilterAssembly LPG Regulator Fuel Line WARNING: Explosive Fuel! LPG is extremely flammable, is heavier than air, and tends to settle in low areas where a spark or flame couldignite th...

5A.2 Section 5ALPG Fuel Systems Operation In a liquid withdrawal system, the Liquefied Petroleum Gas (LPG) is released from the bottom of the supplytank under high pressure. Upon opening the shut-offvalve on the tank, liquid fuel travels out through thehigh pressure line to the electric lock-off/fil...

5A.3 Section 5A LPG Fuel Systems 5A Engine stalls during operation 1. No fuel.2. Faulty lock-off or blocked filter.3. Improper governor setting.4. Damaged diaphragms within regulator.5. Vacuum line leaking, loose, or pinched.6. Restricted fuel line.7. Loose/leaking fuel enrichment hose (Impco carbur...

5A.4 Section 5ALPG Fuel Systems High Altitude Operation The standard carburetor calibrations will provideproper operation up to altitudes of 1500 m (5000 ft.) . No internal changes are necessary or available foreither carburetor. NOTE: Carburetor adjustments should be made only after the engine has ...

5A.5 Section 5A LPG Fuel Systems 5A 4. Inspect the overall condition of the fuel enrichment hose attached to the carburetor. Itmust be free of cracks, deterioration, anddamage. Disconnect the fuel enrichment hosefrom the carburetor fittings to clean or checkcondition as required. See Figure 5A-6. Re...

5A.7 Section 5A LPG Fuel Systems 5A 3. Insert a 0.025 mm (0.001 in.) feeler gauge between the side of the stop collar and thecarburetor housing, then check or set the positionof the stop collar. The head of the mounting screw must be in contact with the carburetor boss from the back (hose/fitting) s...

5A.8 Section 5ALPG Fuel Systems 2. Manually move the governor lever, with the throttle linkage connected, toward the carburetor as far asit will go. Hold it in this position. 3. Looking down the throat of the carburetor, check that the throttle plate is in the full throttle positionand that the head...

5A.9 Section 5A LPG Fuel Systems 5A Vaporizer Assembly The outer surface of the vaporizer should be kept freeof dirt and debris accumulation, which will cause a lossof vaporization efficiency. Visual inspection andnecessary cleaning should be performed on a regularbasis, more frequently under dusty ...

5B.1 Section 5B EFI Fuel System 5B CH26, CH745 Section 5B Electronic Fuel Injection (EFI) Fuel System Contents Page(s) Description Initial Starting/Priming Procedure .......................................................................................................... 5B.2Fuel Recommendations .....

5B.2 Section 5BEFI Fuel System WARNING: Explosive Fuel! Gasoline is extremely flammable and its vapors canexplode if ignited. Store gasoline only in approvedcontainers, in well ventilated, unoccupied buildings,away from sparks or flames. Do not fill the fuel tankwhile the engine is hot or running, s...

5B.3 Section 5B EFI Fuel System 5B EFI Fuel System Components General The Electronic Fuel Injection (EFI) system is acomplete engine fuel and ignition management design.The system includes the following principalcomponents: • Fuel Pump • Fuel Filter • Fuel Rail • Fuel Line(s) • Fuel Pressure Regulat...

5B.4 Section 5BEFI Fuel System Important Service Notes! • Cleanliness is essential and must be maintainedat all times when servicing or working on the EFIsystem. Dirt, even in small quantities, can causesignificant problems. • Clean any joint or fitting with parts cleaningsolvent before opening to p...

5B.5 Section 5B EFI Fuel System 5B Three different styles of ECU’s have been utilized inEFI production. The first style is easily identified by itsmetal case with large 35 pin connector block, and alsoas MA 1.7 . See Figure 5B-1. The second and third styles have plastic cases, but are smaller in ove...

5B.9 Section 5B EFI Fuel System 5B b. If light stays on or blinking ceases prematurely, the procedure was unsuccessful and must berepeated. Possible causes for unsuccessfullearning may be: 1) Movement occurred ineither the TPS or throttle shaft duringprocedure, 2) Crankshaft movement/rotationwas det...

5B.11 Section 5B EFI Fuel System 5B Figure 5B-12. Cutaway of Oxygen Sensor. The oxygen sensor can function only after beingheated by exhaust temperatures to a minimum of375°C (709°F). A cold oxygen sensor will requireapproximately 1-2 minutes at moderate engine load towarm sufficiently to generate a...

5B.13 Section 5B EFI Fuel System 5B a. If there is no continuity displayed in either of the tests, check the harness circuit for breaksor damage, and the connections for poorcontact, moisture, or corrosion. If no continuitywas found in the first test, also check for apoor/broken ground path back thr...

5B.14 Section 5BEFI Fuel System Figure 5B-17. Style 2 Fuel Injector. General The fuel injectors mount into the intake manifold, andthe fuel rail attaches to them at the top end.Replaceable O-Rings on both ends of the injectorprevent external fuel leakage and also insulate it fromheat and vibration. ...

5B.15 Section 5B EFI Fuel System 5B When the key switch is on and the relay is closed, thefuel rail is pressurized, and voltage is present at theinjector. At the proper instant, the ECU completes theground circuit, energizing the injector. The valve needlein the injector is opened electromagneticall...

5B.16 Section 5BEFI Fuel System Figure 5B-21. Injector Inspection Points. 1. Engine must be cool. Depressurize fuel system through test valve in fuel rail. 2. Disconnect spark plug leads from spark plugs. 3. Remove the air cleaner outer cover, inner wing nut, element cover and air cleaner element/pr...

5B.17 Section 5B EFI Fuel System 5B 8. Thoroughly clean the area around and including the throttle body/manifold and the injectors. 9. Disconnect the throttle linkage and damper spring from the throttle lever. Disconnect the TPS leadfrom the harness. 10. Remove the manifold mounting bolts and separa...

5B.19 Section 5B EFI Fuel System 5B Figure 5B-24. “24 Pin” (MSE 1.0) Plastic-CasedECU Connector. Fuel Components Fuel Pump Figure 5B-25. “32 Pin” (MSE 1.1) Plastic-CasedECU Connector. The condition of the wiring, connectors, and terminalconnections is essential to system function andperformance. Cor...

5B.20 Section 5BEFI Fuel System 1. Connect the black hose of Kohler pressure tester (SPX Part No. KO3217-4 ), to the test valve in the fuel rail. Route the clear hose into a portablegasoline container or the equipment fuel tank. 2. Turn on the key switch to activate the pump and check the system pre...

5B.22 Section 5BEFI Fuel System 8. Reconnect the negative (-) battery cable. 9. Recheck regulated system pressure at fuel rail test valve. Fuel Filter EFI engines use a high-volume, high-pressure, 10-15micron, in-line fuel filter. General The fuel rail is a formed tube assembly that feeds fuelto the...

5B.23 Section 5B EFI Fuel System 5B gradually increase to the established setting asoperation continues. Do not attempt to circumvent this warm up period, or readjust the idle speed during thistime. The engine must be completely warmed up foraccurate idle speed adjustment. Adjustment Procedure 1. Ma...

5B.24 Section 5BEFI Fuel System Figure 5B-37. Throttle Linkage/Governor LeverConnection. 2. Check if the engine has a high-speed throttle stop screw installed in the manifold casting boss. SeeFigure 5B-38. The idle speed adjustment procedure remains thesame for engines with or without a dampening sp...

5B.25 Section 5B EFI Fuel System 5B Figure 5B-39. Inserting Feeler Gauge (EnginesWithout Stop Screw). b. On engines with a stop screw, pivot the throttle shaft and plate into the “Full Throttle” position,so the tang of the throttle shaft plate is againstthe end of the high-speed stop screw. SeeFigur...

5B.26 Section 5BEFI Fuel System 4. Verify that the governor has been set correctly. With the linkage still retained in the “Full Throttle”position (Step 2), unsnap the bushing clip,separate the linkage from the bushing, andremove the bushing from the lever. Follow Steps 3and 4 in ‘‘Checking the Init...

5B.27 Section 5B EFI Fuel System 5B Electrical System The EFI system is a 12 VDC negative ground system,designed to operate down to a minimum of 7.0 volts. Ifsystem voltage drops below this level, the operation ofvoltage sensitive components such as the ECU, fuelpump, and injectors will be intermitt...

5B.28 Section 5BEFI Fuel System Pin # 123456789 10 11 121314151617181920212223242526272829303132333435 Component Ignition Coil #1 Not used Engine Speed Sensor ECU Production Test Terminal Not UsedNot UsedNot Used TPS Initialization Terminal Engine Ground O 2 Sensor Not Used Throttle Position Sensor ...

5B.31 Section 5B EFI Fuel System 5B “24 Pin” (MSE 1.0) Plastic-Cased ECU Systems Pin # 123456789 10 11 12131415161718192021222324 Function 1 Permanent Battery VoltageSwitched Ignition VoltageSafety SwitchThrottle Position Sensor (TPS) and Temperature Sensor Ground Not Used Oil Temperature Sensor Inp...

5B.35 Section 5B EFI Fuel System 5B Long Pause Short Pauses Code 32 3 2 Code 61 1 6 Long Pause Light remains on at end of transmission 1. Diagnostic display initiated through ignition key sequencing. 2. Figure 5B-43. After the problem has been corrected, the fault codes may be cleared as follows. 1....

5B.42 Section 5BEFI Fuel System Code: 56 "32 Pin" (MSE 1.1) Plastic-Cased ECU only. Source: Fuel pump relay circuit open, shortedto ground, or shorted to battery Explanation: Fuel pump, ignition coils, and fuelinjectors will not function because thefuel pump relay circuit is either open,shor...

5B.44 Section 5BEFI Fuel System Flow Chart Diagnostic Aids Diagnostic Aid #1 "SYSTEM POWER" (MIL does not illuminate when key is turned “ on ”) Possible causes: 1. Battery2. Main system fuse3. MIL light bulb burned out4. MIL electrical circuit problem “35 Pin” (MA 1.7) Metal-Cased ECU: Pin c...

5B.45 Section 5B EFI Fuel System 5B Diagnostic Aid #4 “SPEED SENSOR” (MIL does not turn off during cranking). Indicates the ECU is notreceiving a signal from the speed sensor. Possible causes: 1. Speed sensor2. Speed sensor circuit problem “35 Pin” (MA 1.7) Metal-Cased ECU: Pin circuits 3 and 21 “24...

6.1 Section 6 Lubrication System 6 Section 6 Lubrication System General This engine uses a full pressure lubrication system. Thissystem delivers oil under pressure to the crankshaft,camshaft and connecting rod bearing surfaces. Inaddition to lubricating the bearing surfaces, thelubrication system su...

6.3 Section 6 Lubrication System 6 1. Clean the areas around the drain plug, oil filter, oil fill cap and dipstick. 2. Remove one of the oil drain plugs. A drain plug is located on either side of the crankcase; one isadjacent to and below the oil filter, the other isbelow the starter. 3. Allow all o...

6.5 Section 6 Lubrication System 6 To install the switch, follow these steps: 1. Apply pipe sealant with Teflon ® (Loctite ® No. 59241 or equivalent) to the threads of the switch. 2. Install the switch into the tapped hole in the breather cover. See Figure 6-8. 3. Torque the switch to 4.5 N·m (40 in...

7.1 Section 7 Retractable Starter 7 Section 7 Retractable Starter WARNING: Spring Under Tension! Retractable starters contain a powerful, recoil spring that is under tension. Always wear safety goggles whenservicing retractable starters and carefully follow instructions in this section for relieving...

7.4 Section 7Retractable Starter 8. Note the position of the spring and keeper assembly in the pulley. See Figure 7-7. Remove the spring and keeper assembly from thepulley as a package. WARNING: Spring Under Tension! Do not remove the spring from the keeper. Severepersonal injury could result from t...

7.5 Section 7 Retractable Starter 7 4. Place the brake washer in the recess in starter pulley; over the center shaft. 5. Lubricate the brake spring sparingly with grease. Place the spring on the plain washer. Make surethe threads in the center shaft remain clean, dry,and free of grease and oil. 6. A...

8.1 Section 8 Electrical System and Components 8 Section 8 Electrical System and Components This section covers the operation, service and repair ofthe electrical system components. Systems andcomponents covered in this section are: • Spark Plugs• Battery and Charging System• Electronic CD Ignition ...

8.3 Section 8 Electrical System and Components 8 2. Keep the cables, terminals, and external surfaces of the battery clean. A build-up of corrosive acid orgrime on the external surfaces can cause thebattery to self-discharge. Self-discharge occursrapidly when moisture is present. 3. Wash the cables,...

8.4 Section 8Electrical System and Components The SMART-SPARK ™ ignition system used on some models is an advanced version of the CD ignitionsystem used on other CH engines. Its operation canbe best understood by first understanding the standardsystem and how it works. Since both systems willcontinu...

8.5 Section 8 Electrical System and Components 8 Figure 8-4. Capacitive Discharge (Fixed Timing) Ignition System. Kill Switch or‘‘Off’’ Position ofKey Switch IgnitionModules Spark Plug Magnet Flywheel (0.28/0.33 mm)0.011/0.013 in. Air Gap L1 D1 C1 T1 P S Spark Plug L2 SCS Figure 8-5. Capacitive Disc...

8.7 Section 8 Electrical System and Components 8 The pulse generated by the input coil of the ignitionmodule (L1, Figure 8-5) is fed to the input of theconditioning circuit. The conditioning circuit shapes thispulse, putting it in a useable form for the additionalcircuits. This pulse starts the char...

8.9 Section 8 Electrical System and Components 8 Figure 8-9. 3. Run the engine at idle and use the timing light beam to locate the line on the screen. Draw a lineon the blower housing adjacent to the line on thescreen. Accelerate to full throttle and watch formovement of the line on the screen relat...

8.11 Section 8 Electrical System and Components 8 terminal of the ground lead or the groundscrew/bolt. Check the voltage with the keyswitch in both the “START” and “RUN”positions. A minimum of 7.25 volts must be present. a. If correct voltage is not measured, connect black voltmeter lead directly to...

8.12 Section 8Electrical System and Components Figure 8-12. 2. Check the SAM part number, stamped on the side of the housing, and determine if you have ananalog SAM (ASAM) or a digital SAM (DSAM).Follow sub-step a for an ASAM, and sub-step bfor a DSAM. To help identify Service Bulletin 233lists DSAM...

8.13 Section 8 Electrical System and Components 8 Battery Charging System General Most engines are equipped with a 15 or 20 ampregulated charging system. Some have a 25 ampregulated charging system. See Figure 8-14 for the15/20/25 amp charging system diagram. Someengines utilize a 3 amp unregulated ...

8.15 Section 8 Electrical System and Components 8 Figure 8-17. 25 amp Stator and Rectifier-Regulators. Ground-To-Kill Lead (White) Diode KeySwitch OptionalOil Sentry TM Switch(Indicator Light) OptionalOil Sentry TM Switch(Shutdown) 12 V. Battery Solenoid Starter Lights (Yellow) (Black) 3 Amp/70 Watt...

8.16 Section 8Electrical System and Components Figure 8-19. 3 amp/70 Watt Stator. Stator The stator is mounted on the crankcase behind theflywheel. Follow the procedures in Section 9 -“Disassembly” and Section 11 - “Reassembly” if statorreplacement is necessary. Rectifier-Regulator The rectifier-reg...

8.17 Section 8 Electrical System and Components 8 3. Plug the tester into a 110 volt AC outlet supply and turn on the power switch. See Figure 8-22.The ‘‘POWER’’ light should be illuminated andone of the four status lights may be on as well.This does not represent the condition of the part. Figure 8...

8.18 Section 8Electrical System and Components 6. Press the ‘‘TEST’’ button until a ‘‘click’’ is heard and then release. See Figure 8-23. Momentarilyone of the four lights will illuminate indicating the partial condition of the part. a. If the ‘‘OK’’ (green) light comes on, disconnect the tester bla...

8.19 Section 8 Electrical System and Components 8 Figure 8-28. 3. Plug the tester into a 110 volt AC outlet and turn on the power switch. The ‘‘POWER’’ light shouldbe illuminated and one of the four status lightsmay be on as well. See Figure 8-22. This does not represent the condition of the part. 4...

8.20 Section 8Electrical System and Components Problem Test Conclusion 1. Trace B+ lead from rectifier-regulator to key switch, or other accessible connection.Disconnect it from switch or connection.Connect an ammeter from loose end of B+lead to positive terminal of battery. ConnectDC voltmeter from...

8.21 Section 8 Electrical System and Components 8 Troubleshooting Guide 3 amp Battery Charging System with 70 Watt Lighting Stator NOTE: Zero ohmmeters on each scale to ensure accurate readings. Voltage tests should be made with engine running at 3000 RPM - no load. Battery must be good and fully ch...

8.25 Section 8 Electrical System and Components 8 Retaining Ring Installation 1. Position the retaining ring in the groove in one of the inner halves. Assemble the other half over thetop and slide on the outer collar. 2. Be certain the drive components are installed in correct sequence onto the arma...

8.27 Section 8 Electrical System and Components 8 Figure 8-38. Style ‘‘B’’ Commutator End Cap withBrushes. 6. Install the thru bolts and tighten securely. 7. Lubricate the drive shaft with Kohler bendix starter drive lubricant (Part No. 52 357 01-S ). Install the drive components following the instr...

8.29 Section 8 Electrical System and Components 8 Figure 8-41. Removing Solenoid Screws. 3. If the solenoid was mounted with Phillips head screws, separate the solenoid and plunger springfrom the drive end cap. If the solenoid wasmounted with external Torx head screws, theplunger is part of the sole...

8.31 Section 8 Electrical System and Components 8 Figure 8-50. Removing Retaining Ring. 12. Remove the drive pinion assembly from the armature. 13. Clean the parts as required. NOTE: Do not soak the armature or use solvent when cleaning. Wipe clean using a soft cloth,or use compressed air. Figure 8-...

8.32 Section 8Electrical System and Components Figure 8-52. Checking Brushes. Armature 1. Clean and inspect the commutator (outer surface). The mica insulation must be lower thanthe commutator bars (undercut) to ensure properoperation of the commutator. See Figure 8-53. Figure 8-54. Checking Armatur...

8.33 Section 8 Electrical System and Components 8 Figure 8-56. Service Brush Kit. 5. Perform Steps 10-13 in the “Starter Reassembly” sequence. Installation must be done after thearmature, drive lever, and frame are installed, ifthe starter has been disassembled. Brush Replacement The brushes and spr...

8.35 Section 8 Electrical System and Components 8 Figure 8-62. Installing Thrust Washer. 10. Starter reassembly when replacing the Brushes/ Brush Holder Assembly: a. Hold the starter assembly vertically on the end housing, and carefully position the assembledbrush holder assembly, with the suppliedp...

9.1 Section 9 Disassembly 9 Section 9 Disassembly WARNING: Accidental Starts! Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disconnect negative (-)battery cabl...

9.3 Section 9 Disassembly 9 Figure 9-7. Removing Oil Cooler. 4. An oil cooler is standard equipment on some models and an option on others. It may be a castaluminum housing, part of the oil filter adapter, orattached to the blower housing, separated fromthe oil filter adapter. If so equipped, remove...

9.4 Section 9Disassembly Figure 9-11. Removing Tube from Breather Cover. 6. Remove the rubber breather tube from the breather cover. See Figure 9-11. Remove Fuel Pump WARNING: Explosive Fuel! Gasoline is extremely flammable and its vapors canexplode if ignited. Store gasoline only in approvedcontain...

9.5 Section 9 Disassembly 9 Figure 9-15. Removing Screws Holding Fuel Pump(Metal Bodied Pump Shown). 4. Note or mark the orientation of the fuel pump, then remove the fuel pump with lines attached asshown in Figure 9-16. Figure 9-16. Remove Fuel Pump and Lines. Mechanical Fuel Pump The mechanical st...

9.6 Section 9Disassembly Figure 9-19. Rear Air Cleaner Bracket (Some Models). 2. Mark the spring hole locations and disconnect the spring from the governor lever. See Figure 9-20. Figure 9-20. Disconnecting Spring from Bracket. 3. Remove the choke linkage from the choke actuator lever and carburetor...

9.7 Section 9 Disassembly 9 3. Remove the carburetor, throttle linkage and governor lever as an assembly. See Figure 9-24. Figure 9-26. Removing Electric Starter Motor. 3. Remove the starter assembly and any spacers (if used). Remove Outer Baffles and Blower Housing 1. Disconnect the plug from the r...

9.9 Section 9 Disassembly 9 Figure 9-34. Removing Fasteners Holding Baffleand Breather Cover. 2. Remove both inner baffles. See Figure 9-35. Figure 9-35. Removing Inner Baffles. 3. Remove the two remaining screws holding the breather cover to the crankcase. See Figure 9-35. 4. Pry under the protrudi...

9.10 Section 9Disassembly 7. Remove the hex. flange screw, breather reed retainer and breather reed. See Figure 9-39. Figure 9-39. Removing Breather Reed. Remove Valve Covers Three valve cover designs have been used. Theearliest type used a gasket and RTV sealant betweenthe cover and sealing surface...

9.11 Section 9 Disassembly 9 Figure 9-41. Disconnecting Leads from IgnitionModules. 2. Rotate the flywheel so the magnet is away from the modules. 3. Remove the mounting screws and ignition modules. Note the position of ignition modules. Figure 9-42. Position of SMART-SPARK ™ Ignition Module. Remove...

9.12 Section 9Disassembly Figure 9-46. Removing Cylinder Head Fasteners. 2. Mark the position of the push rods as either intake or exhaust and cylinder 1 or 2. Push rods shouldalways be reinstalled in the same positions. 3. Carefully remove the push rods, cylinder heads and head gaskets. See Figure ...

9.13 Section 9 Disassembly 9 Figure 9-48. Removing Hydraulic Lifter. Figure 9-47. Removing Cylinder Head Assembly. 4. Remove the lifters from the lifter bores. Use Hydraulic Lifter Tool (SPX Part No. KO1044) Donot use a magnet to remove lifters. Mark thelifters by location, as either intake or exhau...

9.15 Section 9 Disassembly 9 Figure 9-55. Removing Plastic Type Grass Screen. 2. Remove the four hex. flange screws and fan. See Figure 9-56. Figure 9-56. Removing Fan. Remove Flywheel 1. Use a flywheel strap wrench or holding tool (see Section 2) to hold the flywheel and loosen thehex. flange screw...

9.16 Section 9Disassembly Figure 9-63. Breaking Seal on Top Splitting Tab. Governor Gear Assembly The governor gear assembly is located inside theclosure plate. If service is required, refer to the serviceprocedures under ‘‘Governor Gear Assembly’’ inSection 10. Oil Pump Assembly The oil pump is mou...

9.17 Section 9 Disassembly 9 Figure 9-65. Removing Connecting Rod Bolts. NOTE: If a carbon ridge is present at the top of either cylinder bore, use a ridge reamertool to remove the ridge beforeattempting to remove the piston. Figure 9-64. Removing Camshaft (Note Shim). Remove Connecting Rods with Pi...

9.18 Section 9Disassembly Figure 9-68. Removing Crankshaft. Remove Governor Cross Shaft 1. Remove the hitch pin and plain washer, or the retainer and nylon washer, from the governorcross shaft. See Figures 9-69 and 9-70. Remove Crankshaft 1. Carefully pull the crankshaft from the crankcase. See Figu...

10.1 Section 10 Inspection and Reconditioning 10 Section 10 Inspection and Reconditioning This section covers the operation, inspection, andrepair/reconditioning of major internal enginecomponents. The following components are notcovered in this section. They are covered in sectionsof their own: Air...

10.3 Section 10 Inspection and Reconditioning 10 Check the cylinder bore wall for scoring. In severecases, unburned fuel can cause scuffing and scoringof the cylinder wall. It washes the necessary lubricatingoils off the piston and cylinder wall. As raw fuel seepsdown the cylinder wall, the piston r...

10.4 Section 10Inspection and Reconditioning The final cleaning operation should always be athorough scrubbing with a brush and hot, soapy water.Use a strong detergent that is capable of breakingdown the machining oil while maintaining a good levelof suds. If the suds break down during cleaning,disc...

10.5 Section 10 Inspection and Reconditioning 10 EXHAUSTVALVE E G F H D D C A B A B A F E G H INTAKE VALVE EXHAUSTINSERT INTAKEINSERT A BCD E F G H Seat AngleInsert O.D.Guide DepthGuide I.D.Valve Head DiameterValve Face AngleValve Margin (Min.)Valve Stem Diameter Dimension 89°36.987/37.013 mm (1.456...

10.7 Section 10 Inspection and Reconditioning 10 Excessive Combustion Temperatures: The white deposits seen here indicate very high combustiontemperatures, usually due to a lean fuel mixture. Gum: Gum deposits usually result from using stale gasoline. Gum is a prevalent cause of valve sticking.The c...

10.8 Section 10Inspection and Reconditioning Valve Guides If a valve guide is worn beyond specifications, it will notguide the valve in a straight line. This may result inburnt valve faces or seats, loss of compression, andexcessive oil consumption. To check valve guide-to-valve stem clearance,thoro...

10.9 Section 10 Inspection and Reconditioning 10 Ring failure is usually indicated by excessive oilconsumption and blue exhaust smoke. When ringsfail, oil is allowed to enter the combustion chamberwhere it is burned along with the fuel. High oilconsumption can also occur when the piston ring endgap ...

10.11 Section 10 Inspection and Reconditioning 10 Figure 10-12. Piston Ring Installation. 1. Oil Control Ring (Bottom Groove): Install the expander and then the rails. Make sure the endsof expander are not overlapped. 2. Middle Compression Ring (Center Groove): Install the center ring using a piston...

10.12 Section 10Inspection and Reconditioning Figure 10-13. Removing Governor Gear. 2. Remove the locking tab thrust washer located under the governor gear assembly. 3. Carefully inspect the governor gear shaft and replace it only if it is damaged. After removing thedamaged shaft, press or lightly t...

10.13 Section 10 Inspection and Reconditioning 10 3. Install the rotor. 4. Install the oil pump body to the closure plate and secure with the two hex. flange screws. Torquethe hex. flange screws as follows: First Time Installation: 10.7 N·m (95 in. lb.)All Reinstallations: 6.7 N·m (60 in. lb.) 5. Af...

11.1 Section 11 Reassembly 11 Section 11 Reassembly General NOTE: Make sure the engine is assembled using all specified torque values, tightening sequencesand clearances. Failure to observespecifications could cause severe enginewear or damage. Always use new gaskets. Make sure all traces of any cle...

11.5 Section 11 Reassembly 11 Figure 11-14. Checking Camshaft End Play. 3. Apply pressure on the camshaft end play checking tool (pushing camshaft towardcrankshaft). Use a feeler gauge to measure thecamshaft end play between the shim spacer andthe checking tool. Camshaft end play should be 0.076/0.1...

11.6 Section 11Reassembly Remove the closure plate. If end play requiresadjustment, remove the original spacer and install theappropriate size shim spacer in its place. Then followthe procedure under “Install Closure Plate Assembly.” Install Closure Plate Oil Seal 1. Check to make sure that there ar...

11.7 Section 11 Reassembly 11 Figure 11-19. Closure Plate Sealant Pattern. 4. Make sure the end of the governor cross shaft is lying against the bottom of cylinder 1 inside thecrankcase. See Figure 11-13. 5. Install the closure plate to the crankcase. Carefully seat the camshaft and the crankshaftin...

11.8 Section 11Reassembly Install Flywheel WARNING: Damaging Crankshaft andFlywheel Can Cause Personal Injury! Using improper procedures to install the flywheel cancrack or damage the crankshaft and/or flywheel. Thisnot only causes extensive engine damage, but canalso cause personal injury, since br...

11.9 Section 11 Reassembly 11 Figure 11-29. Installing and Torquing FlywheelFastener. Install Flywheel Fan 1. Install the fan onto the flywheel using the four hex. flange screws. NOTE: Position the ears located at rear perimeter of the fan in the recesses ofthe flywheel. See Figure 11-30. Figure 11-...

11.11 Section 11 Reassembly 11 Figure 11-36. Match Numbers on Cylinder Barrel andHead. Figure 11-38. Valve Components. IntakeValveSeal Valve Keepers Retainer Spring Cap Figure 11-39. Installing Valves with Valve SpringCompressor. Install Cylinder Heads NOTE: Cylinder heads must be attached with the ...

11.13 Section 11 Reassembly 11 Figure 11-43. Installing New Mounting Studs toSpecified Height. 4. Check that the dowel pins are in place and install a new cylinder head gasket (printing up). 5. Install the cylinder head. Match the numbers on the cylinder heads and the crankcase. See Figure11-36. Mak...

11.15 Section 11 Reassembly 11 Figure 11-50. Setting Ignition Module Air Gap. 6. Torque the screws to 4.0 N·m (35 in. lb.) . 7. Repeat steps 4 through 6 for the other ignition module. 8. Rotate the flywheel back and forth checking for clearance between the magnet and ignitionmodules. Make sure the m...

11.16 Section 11Reassembly Figure 11-56. Installing Breather Reed Assembly. 4. Insert the breather filter into position in the crankcase. Make sure no filter strands are on thesealing surface. See Figure 11-57. 5. Install the new breather gasket. Figure 11-54. Connecting Kill Leads on StandardIgniti...

11.17 Section 11 Reassembly 11 Figure 11-58. Installing Screws (Locations 3 and 4). 7. Install the inner baffles using the two remaining hex. flange screws (see Figures 11-59 and 11-60)and finger tighten. Do not torque the screws at this time; they will be tightened after the blowerhousing and outer...

11.19 Section 11 Reassembly 11 Figure 11-67. Breather Cover Fastener TorqueSequence. Reconnect Rectifier-Regulator 1. Install the rectifier-regulator in the blower housing, if removed previously, then connect the rectifier-regulator ground lead with the washer and silverscrew through the eyelet as s...

11.20 Section 11Reassembly Figure 11-71. Reinstalling SAM Module. Install Electric Starter Motor 1. Install the starter motor using the two hex. flange screws. See Figure 11-72. Some inertia-drivestarters have a pinion cover and spacers on thestarter bolts. 2. Torque the two hex. flange screws to 15...

11.21 Section 11 Reassembly 11 Figure 11-74. Reinstalled Fuel Pump. Install Carburetor WARNING: Explosive Fuel! Gasoline may be present in the carburetor and fuelsystem. Gasoline is extremely flammable and itsvapors can explode if ignited. Keep sparks and othersources of ignition away from the engin...

11.22 Section 11Reassembly Figure 11-78. Adjusting Governor Lever. 4. Insert a nail into the hole on the cross shaft and rotate the shaft counterclockwise as far as it will turn, then torque the hex. nut to 6.8 N·m (60 in. lb.) . See Figure 11-79. Figure 11-79. Holding and Tightening Governor Arm. 5...

11.23 Section 11 Reassembly 11 Figure 11-82. Connecting Spring to GovernorLever. 3. Connect the governor spring from the main control bracket to the appropriate hole in thegovernor lever as indicated in the following charts.Note that hole positions are counted from thepivot point of the governor lev...

11.24 Section 11Reassembly CH26,CH745 EFI Engines Governor Shaft Configuration High Idle WOT Intended Maximum RPM Spring Color Hole No. CH20-740 Engines Accelerator Pump Carburetor Spring Color Hole No. -- -- Purple Black Red Orange Blue Orange Black Red Clear 333221111 Governor Shaft Configuration ...

11.25 Section 11 Reassembly 11 Figure 11-83. Throttle/Choke Control Bracket Detail. Install Oil Sentry ™ (If So Equipped) 1. Apply pipe sealant with Teflon ® (Loctite ® No. 59241 or equivalent) to the threads of the OilSentry ™ switch and install it into the breather cover. See Figure 11-84. Torque ...

11.26 Section 11Reassembly Install Valve Covers Three valve cover designs have been used. Theearliest type used a gasket and RTV sealant betweenthe cover and sealing surface of the cylinder head. Thesecond type had a black O-Ring installed in a grooveon the underside of the cover and may have metals...

11.27 Section 11 Reassembly 11 Figure 11-87. Connecting Fuel Inlet Line. 2. Position a new gasket and the air cleaner base while carefully pulling the loose end of the rubberbreather hose through the base until properlyseated (collars sealed against each side of base).See Figure 11-88. Figure 11-88....

11.28 Section 11Reassembly Figure 11-92. Torquing Oil Filter Nipple. Install Oil Cooler 1. Reinstall the oil cooler on the engine (if equipped). Install a new gasket between the cooler and theclosure plate. Torque nipple adapter to 27 N·m (20 ft. lb.) . See Figure 11-92. Figure 11-93. Installing New...

11.29 Section 11 Reassembly 11 Figure 11-96. Reinstall the Dipstick in Tube. 6. Make sure the O-Ring is in place then reinstall the oil fill cap on the valve cover. See Figure 11-97. Figure 11-97. Reinstalling Oil Fill Cap (Some Models). Connect Spark Plug Leads 1. Connect the leads to the spark plu...

12.1 Section 12 Clutch 12 Section 12 Clutch CH18-745 Clutch General Some engines are equipped with a “wet” disc type clutch. See Figure 12-1 for exploded view of clutch. Figure 12-1. Wet Type Clutch - Exploded View. Nameplate Gasket Shifting Lever Seal Shaft(Yoke) ClutchHousing Key Yoke Roll Pin Bal...

12.2 Section 12Clutch Service On this type, an oil “splash” type lubrication system isused. The proper oil level must be maintained toprovide efficient lubrication. The oil should be changedafter each 100 hours of operation. When refilling, use0.47 L (1 pt.) of motor oil of proper viscosity. See cha...