Kohler CH18-745 manuale d’uso

S ER VICE M ANUAL H ORIZONT AL C RANKSHAFT COMMAND CH18-745[...]

1.1 Section 1 Safety and General Information 1 Section 1 Safety and General Information CH18-745 Safety Precautions T o ensure safe operation please read the following statements and understand their meaning. Also refer to your equipment manufacturer's manual for other important safety information. This manual contains safety precautions which[...]

1.2 Section 1 Safety and General Information Carbon Monoxide can cause severe nausea, fainting or death. Do not operate engine in closed or confined area. W ARNING W ARNING Electrical Shock can cause injury . Do not touch wires while engine is running. CAUTION Uncoiling Spring can cause severe injury . Wear safety goggles or face protection when se[...]

1.3 Section 1 Safety and General Information 1 A . Model No. V ersion Code S = Electric S tart C H 18 S Engine Identification Numbers When ordering parts, or in any communication involving an engine, always give the Model, Specification and Serial Numbers, including letter suffixes if there are any . The engine identification numbers appear on a de[...]

1.4 Section 1 Safety and General Information Oil Recommendations Using the proper type and weight of oil in the crankcase is extremely important. So is checking oil daily and changing oil regularly . Failure to use the correct oil, or using dirty oil, causes premature engine wear and failure. Oil T yp e Use high-quality detergent oil of API (Americ[...]

1.5 Section 1 Safety and General Information 1 Periodic Maintenance Instructions W ARNING: Accidental St arts! Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disconnect negative (-) battery cable from battery .[...]

1.6 Section 1 Safety and General Information Figure 1-4. T ypical Engine Dimensions CH Series with Standard Flat Air Cleaner . Dimensions in millimeters. Inch equivalents shown in ().[...]

1.7 Section 1 Safety and General Information 1 Figure 1-5. T ypical Engine Dimensions CH EFI Series with Heavy-Duty Air Cleaner . Dimensions in millimeters. Inch equivalents shown in ().[...]

1.8 Section 1 Safety 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 ...................................................................................... 0.025/0.063 mm (0.0010/0.0025 in.) Bore I.D. New .[...]

1.10 Section 1 Safety and General Information Closure Plate Closure Plate Fastener T orque .............................................................. 24.4 N·m (216 in. lb.) Crankshaft End Play (Free) .................................................................................... 0.070/0.590 mm (0.0028/0.0230 in.) End Play (With Thrust Bea[...]

1.11 Section 1 Safety and General Information 1 Cylinder Head Cylinder Head Fastener T orque Hex. Flange Nut - T orque in T wo S tages .......................................... initially to 16.9 N·m (150 in. lb.) finally to 33.9 N·m (300 in. lb.) Head Bolt - T orque in T wo S t ages .................................................. initially to[...]

1.12 Section 1 Safety 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 T orque .................................................................. 24.4 N·m (216 in. lb.) Oil Filter Oil Filter T orque ..............................................[...]

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 1 Safety and General Information V alves and V alve Lifters cont. Exhaust V alve Guide I.D. New ................................................................................................ 7.038/7.058 mm (0.2771/0.2779 in.) Max. Wear Limit ............................................................................. 7.159 mm (0.281[...]

1.15 Section 1 Safety and General Information 1 English Fastener T orque Recommendations for S tandard Applications Grade 2 or 5 Fasteners Into Aluminum Size 8-32 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) 13.0 (1 15) 18.7 (165) 7.9 (70) 1/4-28 9.6 (85)[...]

1.16 Section 1 Safety and General Information[...]

2.1 Section 2 S pecial T ools 2 Section 2 S pecial T ools 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 increase your service capabilities and customer satisfact[...]

2.2 Section 2 Special T ools Figure 2-1. T ool Cat alog and Price List. Special T ools Y ou Can Make Flywheel Holding T ool Flywheel removal and reinstallation becomes a “snap” using a handy holding tool which can be made out of an old “junk” flywheel ring gear as shown in Figure 2-2. Using an abrasive cut-off wheel, cut out a six tooth seg[...]

2.3 Section 2 S pecial T ools 2 Figure 2-5. Loctite ® 5900 Aerosol Dispenser. Camshaft Break-in Lubricant Camshaft lubricant, Kohler Part No. 25 357 14-S (V alspar ZZ613), should be used whenever a new camshaft and lifters are inst alled for proper break-in upon initial startup. Lubricant is included with each replacement camshaft and lifter , or [...]

2.4 Section 2 Special T ools[...]

3.1 Section 3 T roubleshooting 3 Section 3 T roubleshooting T roubleshooting Guide When troubles occur , be sure to check the simple causes which, at first, may seem too obvious to be considered. For example, a starting problem could be caused by an empty fuel tank. Some general common causes of engine troubles are listed below . Use these to locat[...]

3.2 Section 3 T roubleshooting Engine Will Not Idle 1. Dirt or water in the fuel system. 2. S tale 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. Restricted fuel tank cap vent. 9. Engine[...]

3.3 Section 3 T roubleshooting 3 • Check the condition of the oil. Drain the oil into a container - the oil should flow freely . Check for metal chips and other foreign particles. Sludge is a natural by-product of combustion; a small accumulation is normal. Excessive sludge formation could indicate overrich carburetion, weak ignition, overextende[...]

3.4 Section 3 T roubleshooting Compression T est Some of these engines are equipped with an automatic compression release (ACR) mechanism. Because of the ACR mechanism, it is dif ficult to obt ain an accurate compression reading. As an alternative, perform a cylinder leakdown test. Cylinder Leakdown T est A cylinder leakdown test can be a valuable [...]

3.5 Section 3 T roubleshooting 3 Leakdown T est Results Air escaping from crankcase breather ................................................... Defect ive rings or worn cylinder . Air escaping from exhaust system ......................................................... Defective exhaust valve. Air escaping from carburetor ........................[...]

3.6 Section 3 T roubleshooting[...]

4.1 Section 4 Air Cleaner and Air Int ake System 4 Section 4 Air Cleaner and Air Int ake System Air Cleaners General Most engines are equipped with a replaceable, high- density paper air cleaner element, surrounded by an oiled foam precleaner , and housed under a flat outer cover . This is typically referred to as the standard air cleaner assembly [...]

4.2 Section 4 Air Cleaner and Air Intake System 3. W ash the precleaner in warm water with detergent. Rinse the precleaner thoroughly until all traces of detergent are eliminated. Squeeze out excess water (do not wring). Allow the precleaner to air dry . 4. Saturate the precleaner with new engine oil. Squeeze out all excess oil. 5. Reinstall the pr[...]

4.3 Section 4 Air Cleaner and Air Int ake System 4 5. Check the seal for any damage or deterioration. Replace as necessary . See Figure 4-7. 6. Reinstall the seal, p aper element, precleaner , element cover , and wing nut. 7. Reinstall the air cleaner cover and secure with the latches or the retaining knob. NOTE: Make sure the correct depth air cle[...]

4.4 Section 4 Air 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 the wing nut and seal are in place to ensure the element is sealed against leakage. Air Cleaner Base - Make sure the base is secured tightly to the carburetor and not cr[...]

4.5 Section 4 Air Cleaner and Air Int ake System 4 Figure 4-12. Heavy-Duty Air Cleaner . T o Service Every 250 hours of operation (more of ten under extremely dusty or dirty conditions), replace the paper element and check the inner element. Follow these steps. 1. Unhook the two retaining clip s and remove the end cap from the air cleaner housing. [...]

4.6 Section 4 Air Cleaner and Air Intake System Figure 4-14. Adapters for Heavy-Duty Air Cleaners. Air Int ake/Cooling System T o ensure proper cooling, make sure the grass screen, cooling fan fins, and external surfaces of the engine are kept clean at all times . Every 100 hours of operation (more of ten under extremely dusty or dirty conditions),[...]

5.1 Section 5 Fuel System and Governor 5 Section 5 Fuel System and Governor Description The Command horizontal twins use three dif ferent types of fuel systems; carbureted, electronic fuel injection (EFI), or gaseous. Gaseous fuel systems can be either liquefied petroleum gas (LPG or LP) or natural gas (NG). Some dual-fuel engines have a combinatio[...]

5.2 Section 5 Fuel System and Governor Gasoline/Ether blends Methyl T ertiary Butyl Ether (MTBE) and unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved as a fuel for Kohler engines. Other gasoline/ether blends are not approved. T roubleshooting – Fuel System Related Causes Fuel Filter Most engines are equipped with an i[...]

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 to the valve cover . 4. Install the new fuel pump using the hex. flange screws. T orque the hex. flange screws to 2.3 N·m (20 in. lb.) . NOTE: Make sure the orientation of the new pump is [...]

5.4 Section 5 Fuel System and Governor Carburetor General These engines are equipped with fixed main jet carburetors manufactured by Keihin to Kohler specifications. Most have automatic chokes and fuel shut-off solenoids. Keihin carburetors with accelerator pump features are standard on many models, and are furnished as an option on other CH applic[...]

5.5 Section 5 Fuel System and Governor 5 T roubleshooting Checklist When the engine starts hard, runs roughly or st alls at low idle speed, check the following areas before adjusting or disassembling the carburetor . • Make sure the fuel tank is filled with clean, fresh gasoline. • Make sure the fuel tank cap vent is not blocked and that it is [...]

5.6 Section 5 Fuel System and Governor Figure 5-4. Pre-Compliance Carburetor with Low Idle 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. Damage to the needle and the seat in the carburetor bod[...]

5.7 Section 5 Fuel System and Governor 5 Figure 5-6. Carburetor Det ail. 5. Hold the carburetor upper body so that the float assembly hangs vertically and rests lightly against the fuel inlet needle. The fuel inlet needle should be fully seated, but the needle tip should not be depressed. See Figure 5-7. NOTE: The fuel inlet needle tip is spring lo[...]

5.8 Section 5 Fuel System and Governor 7. In order to clean the ‘‘of f-idle’’ vent port s and bowl vent thoroughly , use a good carburetor solvent (like Gumout ™ ). Blow clean compressed air through the idle adjusting needle hole. Be careful to use a suitable shop rag to prevent debris from hitting someone. 8. Remove the preformed rubber [...]

5.9 Section 5 Fuel System and Governor 5 1. Carburetor Upper Body (Choke) 2. Self-relieving Choke 3. Body Gasket (Formed Rubber) 4. Slow S peed Jet 5. Inlet Needle V alve 6. Clip 7. Float Pin 8. Float Assembly (Kit) 9. Carburetor Lower Body (Throttle) 10. Main Jet 1 1. Idle Fuel Adjusting Needle (some models) 12. Solenoid Seat 13. Fuel Shut-off Sol[...]

5.10 Section 5 Fuel 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 the air horn. T ighten the screw . Check float height using the procedure found previously in the ‘‘Adjustment s’’ subs[...]

5.11 Section 5 Fuel System and Governor 5 General The governed speed setting is determined by the position of the throttle control. It can be variable or constant, depending on the engine application. Initial Adjustment NOTE: EFI engines require a special initial adjustment procedure, which is covered in subsection 5B. Refer to “Initial Governor [...]

5.12 Section 5 Fuel System and Governor Figure 5-13. Electronic Governor Assembly . Digit al Linear Actuator (DLA) Energizing the bi-directional digital linear actuator coils in the proper sequence, causes the threaded shaft to move out of, or back into the rotor , in precise linear increments. When power is removed, the actuator shaft remains in p[...]

5.13 Section 5 Fuel System and Governor 5 Governor Control Unit (GCU) senses engine speed by pulse voltage inputs from the ignition modules. The GCU regulates the engine speed by variable input voltage from a customer-supplied potentiometer or a single pole, single throw (SPST) switch. Potentiometer Specifications: Adjustment Procedure The DLA must[...]

5.14 Section 5 Fuel System and Governor[...]

5A.1 Section 5A LPG Fuel Systems 5A Section 5A LPG Fuel Systems CH18-740 Figure 5A-1. V acuum Line V aporizer Lock-Off/Filter Assembly LPG Regulator Fuel Line W ARNING: Explosive Fuel! LPG is extremely flammable, is heavier than air , and tends to settle in low areas where a spark or flame could ignite the gas. Do not start or operate this engine i[...]

5A.2 Section 5A LPG Fuel Systems Operation In a liquid withdrawal system, the Liquefied Petroleum Gas (LPG) is released from the bottom of the supply tank under high pressure. Upon opening the shut-of f valve on the tank, liquid fuel travels out through the high pressure line to the electric lock-off/filter assembly . The lock-off opens internally [...]

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. V acuum line leaking, loose, or pinched. 6. Restricted fuel line. 7. Loose/leaking fuel enrichment hose (Impco carburetor system). Low power 1. Air cleaner or[...]

5A.4 Section 5A LPG Fuel Systems High Altitude Operation The standard carburetor calibrations will provide proper operation up to altitudes of 1500 m (5000 ft.) . No internal changes are necessary or available for either carburetor . NOTE: Carburetor adjustments should be made only after the engine has warmed up. Idle Speed Adjustment 1. S tart the[...]

5A.5 Section 5A LPG Fuel Systems 5A 4. Inspect the overall condition of the fuel enrichment hose attached to the carburetor . It must be free of cracks, deterioration, and damage. Disconnect the fuel enrichment hose from the carburetor fittings to clean or check condition as required. See Figure 5A-6. Replace with a new Kohler high pressure hose (L[...]

5A.6 Section 5A LPG Fuel Systems LPG Carburetor - Reassembly Impco Carburetor 1. Slide the venturi into the carburetor body , aligning the position mark made prior to removal. Correctly installed, the discharge holes should not be visible from the top. 2. Secure with the venturi retaining screw . T orque the screw to 4.0 N·m (36 in. lb.) . 3. Inst[...]

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 the carburetor housing, then check or set the position of the stop collar . The head of the mounting screw must be in cont act with the carburetor boss from the back (hose/fitting) side, preventing any further rotation over cent[...]

5A.8 Section 5A LPG Fuel Systems 2. Manually move the governor lever , with the throttle linkage connected, toward the carburetor as far as it will go. Hold it in this position. 3. Looking down the throat of the carburetor , check that the throttle plate is in the full throttle position and that the head of the high speed collar stop screw is in co[...]

5A.9 Section 5A LPG Fuel Systems 5A V aporizer Assembly The outer surface of the vaporizer should be kept free of dirt and debris accumulation, which will cause a loss of vaporization efficiency . Visual inspection and necessary cleaning should be performed on a regular basis, more frequently under dusty or dirty conditions. The vaporizer should be[...]

5A.10 Section 5A LPG Fuel Systems Impco (Beam) Regulator (See Figure 5A-20) LPG vapor enters at point (A) , then p asses into primary area (B) at point (28) , where pressure is reduced from up to 250 psi at the tank to 4.5 p si in area (B) . Fuel pressure against diaphragm (2) overcomes spring (3) and as movement increases, spring (5) will close le[...]

5A.11 Section 5A LPG Fuel Systems 5A Nikki Regulator Primary Chamber (See Figure 5A-21) The primary chamber reduces the high pressure fuel flow from the tank and vaporizer down to approximately 4 psi. Fuel flowing from the vaporizer enters the inlet of the regulator under approximately 76 kPa (1 1 psi) of pressure. There it is delivered to the prim[...]

5A.12 Section 5A LPG Fuel Systems Regulator Drain Plug Prevent ative Maintenance The regulator is preset at the factory and generally requires no further adjustment. No periodic service is required. Over time, depending on fuel quality , operating environment, and system performance, fuel deposits can accumulate inside the regulator . Those regulat[...]

5B.1 Section 5B EFI Fuel System 5B CH26, CH745 Section 5B Electronic Fuel Injection (EFI) Fuel System Content s Page(s) Description Initial S tarting/Priming Procedure .......................... ................................................................... .... ..... .... 5B.2 Fuel Recommendations .............................................[...]

5B.2 Section 5B EFI Fuel System W ARNING: Explosive Fuel! Gasoline is extremely flammable and its vapors can explode if ignited. Store gasoline only in approved containers, in well ventilated, unoccupied buildings, away from sparks or flames. Do not fill the fuel tank while the engine is hot or running, since spilled fuel could ignite if it comes i[...]

5B.3 Section 5B EFI Fuel System 5B EFI Fuel System Component s General The Electronic Fuel Injection (EFI) system is a complete engine fuel and ignition management design. The system includes the following principal components: • Fuel Pump • Fuel Filter • Fuel Rail • Fuel Line(s) • Fuel Pressure Regulator • Fuel Injectors • Throttle B[...]

5B.4 Section 5B EFI Fuel System Import ant Service Notes! • Cleanliness is essential and must be maintained at all times when servicing or working on the EFI system. Dirt, even in small quantities, can cause significant problems. • Clean any joint or fitting with parts cleaning solvent before opening to prevent dirt from entering the system. ?[...]

5B.5 Section 5B EFI Fuel System 5B Three different styles of ECU’ s have been utilized in EFI production. The first style is easily identified by it s metal case with large 35 pin connector block, and also as MA 1.7 . See Figure 5B-1. The second and third styles have plastic cases, but are smaller in overall size. These have either a 24 pin or 32[...]

5B.6 Section 5B EFI Fuel System General The engine speed sensor is essential to engine operation; constantly monitoring the rot ational speed (RPM) of the crankshaft. A ferromagnetic 60-tooth ring gear with two consecutive teeth missing is mounted on the flywheel. The inductive speed sensor is mounted 1.5 ± 0.25 mm (0.059 ± 0.010 in.) away from t[...]

5B.7 Section 5B EFI Fuel System 5B Mounted on the throttle body/intake manifold and operated directly off the end of the throttle shaf t, the TPS works like a rheostat, varying the voltage signal to the ECU in direct correlation to the angle of the throttle plate. This signal, along with the other sensor signals, is processed by the ECU and compare[...]

5B.8 Section 5B EFI Fuel System If the resistance values in step s 3, 4, and 5 are within specifications, go to step 6. If the resistance values are not within specifications, or a momentary short or open circuit was detected during rotation (step 4), the TPS needs to be replaced, go to step 7. 6. Check the TPS circuit s (input, ground) between the[...]

5B.9 Section 5B EFI Fuel System 5B b. If light stays on or blinking ceases prematurely , the procedure was unsuccessful and must be repeated. Possible causes for unsuccessful learning may be: 1) Movement occurred in either the TPS or throttle shaf t during procedure, 2) Crankshaft movement/rotation was detected by the speed sensor during procedure,[...]

5B.10 Section 5B EFI Fuel System Figure 5B-10. Engine (Oil) T emperature Sensor . General The engine (oil) temperature sensor (Figure 5B-10) is used by the system to help determine fuel requirements for st arting, (a cold engine needs more fuel than one at or near operating temperature). Mounted in the oil filter adapter housing, it has a temperatu[...]

5B.11 Section 5B EFI Fuel System 5B Figure 5B-12. Cutaway of Oxygen Sensor . The oxygen sensor can function only after being heated by exhaust temperatures to a minimum of 375°C (709°F). A cold oxygen sensor will require approximately 1-2 minutes at moderate engine load to warm sufficiently to generate a voltage signal. Proper grounding is also c[...]

5B.12 Section 5B EFI Fuel System 1. Oxygen sensor must be hot (minimum of 400°C, 725°F). Run engine for about 5 minutes. With the engine running, disconnect the oxygen sensor lead from the wiring harness. Set VOA meter for DC volts and connect the red lead to the disconnected sensor lead, and the black lead to the sensor shell. Check for a voltag[...]

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 breaks or damage, and the connections for poor contact, moisture, or corrosion. If no continuity was found in the first test, also check for a poor/broken ground path back through the exhaust system, engine, and mounting [...]

5B.14 Section 5B EFI Fuel System Figure 5B-17. Style 2 Fuel Injector . General The fuel injectors mount into the intake manifold, and the fuel rail attaches to them at the top end. Replaceable O-Rings on both ends of the injector prevent external fuel leakage and also insulate it from heat and vibration. A special clip connects each injector to the[...]

5B.15 Section 5B EFI Fuel System 5B When the key switch is on and the relay is closed, the fuel rail is pressurized, and voltage is present at the injector . At the proper instant, the ECU completes the ground circuit, energizing the injector . The valve needle in the injector is opened electromagnetically , and the pressure in the fuel rail forces[...]

5B.16 Section 5B EFI Fuel System Figure 5B-21. Injector Inspection Point s. 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/ precleaner . Service air cleaner components as r[...]

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 lead from the harness. 10. Remove the manifold mounting bolts and separate the throttle body/manifold from the engine le[...]

5B.18 Section 5B EFI Fuel System 4. If the secondary resistance is not within the specified range, unscrew the spark plug lead nut from the coil secondary tower and remove the plug lead. Repeat step b. 3, testing from the secondary tower terminal to the red primary terminal. If resistance is now correct, the coil is good, but the spark plug lead is[...]

5B.19 Section 5B EFI Fuel System 5B Figure 5B-24. “24 Pin” (MSE 1.0) Plastic-Cased ECU Connector . Fuel Component s Fuel Pump Figure 5B-25. “32 Pin” (MSE 1.1) Plastic-Cased ECU Connector . The condition of the wiring, connectors, and terminal connections is essential to system function and performance. Corrosion, moisture, and poor connecti[...]

5B.20 Section 5B EFI Fuel System 1. Connect the black hose of Kohler pressure tester (SPX Part No. KO3217-4 ), to the test valve in the fuel rail. Route the clear hose into a portable gasoline container or the equipment fuel tank. 2. T urn on the key switch to activate the pump and check the system pressure on the gauge. If system pressure of 39 ps[...]

5B.21 Section 5B EFI Fuel System 5B Figure 5B-29. Fuel Pressure Regulator Det ails. Service Depending on the application, the regulator may be located in the fuel tank along with the fuel pump, or outside the t ank just down line from the pump. The regulator is a sealed, non-serviceable assembly . If it is faulty , it must be separated from the bas[...]

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

5B.23 Section 5B EFI Fuel System 5B gradually increase to the established setting as operation continues. Do not attempt to circumvent this warm up period, or readjust the idle speed during this time. The engine must be completely warmed up for accurate idle speed adjustment. Adjustment Procedure 1. Make sure there are no fault codes present in the[...]

5B.24 Section 5B EFI Fuel System Figure 5B-37. Throttle Linkage/Governor Lever Connection. 2. Check if the engine has a high-speed throttle stop screw installed in the manifold casting boss. See Figure 5B-38. The idle speed adjustment procedure remains the same for engines with or without a dampening spring. T ypically , no periodic servicing is ne[...]

5B.25 Section 5B EFI Fuel System 5B Figure 5B-39. Inserting Feeler Gauge (Engines Without S top 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 against the end of the high-speed stop screw . See Figure 5B-38. T emporarily clamp in this pos[...]

5B.26 Section 5B EFI Fuel System 4. V erify that the governor has been set correctly . With the linkage still retained in the “Full Throttle” position (S tep 2), unsnap the bushing clip, separate the linkage from the bushing, and remove the bushing from the lever . Follow S tep s 3 and 4 in ‘‘Checking the Initial Adjustment’’. 5. Reconn[...]

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. If system voltage drop s below this level, the operation of voltage sensitive component s such as the ECU, fuel pump, and injectors will be intermittent or disrupted, causing erratic operation [...]

5B.28 Section 5B EFI Fuel System Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Component Ignition Coil #1 Not used Engine S peed Sensor ECU Production T est T erminal Not Used Not Used Not Used TPS Initialization T erminal Engine Ground O 2 Sensor Not Used Throttle Position Sensor Not Used Oil[...]

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5B.31 Section 5B EFI Fuel System 5B “24 Pin” (MSE 1.0) Plastic-Cased ECU Systems Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Function 1 Permanent Battery V oltage Switched Ignition V oltage Safety Switch Throttle Position Sensor (TPS) and T emperature Sensor Ground Not Used Oil T emperature Sensor Input Not Used Throttl[...]

5B.32 Section 5B EFI Fuel System “32 Pin” (MSE 1.1) Plastic-Cased ECU Systems Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Function Permanent Battery V oltage Switched Battery V oltage TPS Set; “Auto-Learn” Initialization T erminal Throttle Position Sensor (TPS) and T emperature Sensor Ground [...]

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5B.34 Section 5B EFI Fuel System Fuel System W ARNING: Fuel System Under Pressure! The fuel system operates under high pressure. System pressure must be relieved through the test valve in the fuel rail prior to servicing or removing any fuel system components. Do not smoke or work near heaters or other fire hazards. Have a fire extinguisher handy a[...]

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. Disconnect the negative (-) battery cable from ba[...]

5B.36 Section 5B EFI Fuel System k n i l B e d o C 2 D B O e d o C - P e l b a c i l p p A " n i P 2 3 " : o t ) 1 . 1 E S M ( - t s y S / U C E y l n O m e n o i t p i r c s e D e r u l i a F r o n o i t c e n n o C " n i P 5 3 " ) 7 . 1 A M ( d e s a C - l a t e M m e t s y S / U C E " n i P 4 2 " ) 0 . 1 E S M ( d e[...]

5B.37 Section 5B EFI Fuel System 5B Code: 21 Source: Engine S peed Sensor Explanation: ECU receiving inconsistent tooth count signals from speed sensor . Expected Engine Response: Possible misfire as ECU attempts to resynchronize, during which time fuel and spark calculations are not made. Possible Causes: 1. Engine S peed Sensor Related a. Sensor [...]

5B.38 Section 5B EFI Fuel System 3. Engine Wiring Harness Related “32 Pin” (MSE 1.1) Plastic-Cased ECU: a. Pin circuits 4, 8, and/or 18 damaged (wiring, connectors). b. Pin circuits 4, 8, and/or 18 routed near noisy electrical signal (coils, alternator). c. Intermittent 5 volt source from ECU (pin circuit 18). 4. ECU/Harness Related a. ECU-to-h[...]

5B.39 Section 5B EFI Fuel System 5B Code: 32 Source: Oxygen Sensor Explanation: No change in the sensor output signal. Expected Engine Response: “Open loop” operation only , may cause a drop in system performance and fuel ef ficiency . Possible Causes: 1. Engine Wiring Harness Related a. Pin circuit wiring or connectors. Pin 10 for “35 Pin”[...]

5B.40 Section 5B EFI Fuel System 3. System Related a. Engine is operating above the 176°C (350°F) temperature sensor limit. Code: 43 and 44 "32 Pin" (MSE 1.1) Plastic- Cased ECU only . Source: TPS “Auto-Learn” initialization function failed, throttle angle out of learning range. Explanation: While performing the TPS “Auto- Learn?[...]

5B.41 Section 5B EFI Fuel System 5B Code: 51 "32 Pin" (MSE 1.1) Plastic- Cased ECU only . Source: Injector #1 circuit open, shorted to ground, or shorted to battery . Explanation: Injector #1 is not functioning because the circuit is open, shorted to ground, or shorted to battery . Expected Engine Response: Engine will run very poorly wit[...]

5B.42 Section 5B EFI Fuel System Code: 56 "32 Pin" (MSE 1.1) Plastic- Cased ECU only . Source: Fuel pump relay circuit open, shorted to ground, or shorted to battery Explanation: Fuel pump, ignition coils, and fuel injectors will not function because the fuel pump relay circuit is either open, shorted to ground, or may be “on” continu[...]

5B.43 Section 5B EFI Fuel System 5B Figure 5B-44. *Operate for an appropriate period of time based upon original fault codes.[...]

5B.44 Section 5B EFI Fuel System Flow Chart Diagnostic Aids Diagnostic Aid #1 "SYSTEM POWER" (MIL does not illuminate when key is turned “ on ”) Possible causes: 1. Battery 2. Main system fuse 3. MIL light bulb burned out 4. MIL electrical circuit problem “35 Pin” (MA 1.7) Met al-Cased ECU: Pin circuits 31 and 31A. “24 Pin” (M[...]

5B.45 Section 5B EFI Fuel System 5B Diagnostic Aid #4 “SPEED SENSOR” (MIL does not turn off during cranking). Indicates the ECU is not receiving a signal from the speed sensor . Possible causes: 1. S peed sensor 2. S peed sensor circuit problem “35 Pin” (MA 1.7) Met al-Cased ECU: Pin circuits 3 and 21 “24 Pin” (MSE 1.0) Plastic-Cased EC[...]

5B.46 Section 5B EFI Fuel System[...]

6.1 Section 6 Lubrication System 6 Section 6 Lubrication System General This engine uses a full pressure lubrication system. This system delivers oil under pressure to the crankshaft, camshaft and connecting rod bearing surfaces. In addition to lubricating the bearing surfaces, the lubrication system supplies oil to the hydraulic valve lifters. A h[...]

6.2 Section 6 Lubrication System NOTE: T o prevent extensive engine wear or damage, always maintain the proper oil level in the crankcase. Never operate the engine with the oil level below the ‘‘L” mark or above the ‘‘F” mark on the dipstick. Changing Oil and Oil Filter Changing Oil Change the oil after every 100 hours of operation (mor[...]

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 is adjacent to and below the oil filter , the other is below the starter . 3. Allow all oil to drain and then reinstall the drain plug[...]

6.4 Section 6 Lubrication System Figure 6-7. Oil Coolers. Inspect and clean the oil cooler every 100 hours of operation (more frequently under severe conditions). In order to be effective, the oil cooler must be kept free of debris. T o service the crankcase mounted oil cooler , clean off the outside fins with a brush or with compressed air . T o s[...]

6.5 Section 6 Lubrication System 6 T o install the switch, follow these step s: 1. Apply pipe sealant with T eflon ® (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. T orque the switch to 4.5 N·m (40 in. lb.) . T esting Compressed air , a press[...]

6.6 Section 6 Lubrication System[...]

7.1 Section 7 Retract able St arter 7 Section 7 Retract able St arter W ARNING: S pring Under T ension! Retractable starters cont ain a powerful, recoil spring that is under tension. Always wear safety goggles when servicing retractable starters and carefully follow instructions in this section for relieving spring tension. CH18-745 T o Remove St a[...]

7.2 Section 7 Retract able St arter Figure 7-3. Installing Rope. 10 . Tie a slipknot approximately 12 in. from the free end of rope. Hold the pulley firmly and allow it to rotate slowly until the slipknot reaches the guide bushing of the housing. 1 1. Slip the handle and rope retainer onto the rope. T ie a single knot at the end of the rope. Instal[...]

7.3 Section 7 Retract able St arter 7 Disassembly W ARNING: Spring Under T ension! Do not remove the center screw from the starter until the spring tension is released. Removing the center screw before releasing spring tension, or improper starter disassembly , can cause the sudden and potentially dangerous release of the spring. Follow these instr[...]

7.4 Section 7 Retract able St arter 8. Note the position of the spring and keeper assembly in the pulley . See Figure 7-7. Remove the spring and keeper assembly from the pulley as a package. W ARNING: S pring Under T ension! Do not remove the spring from the keeper . Severe personal injury could result from the sudden uncoiling of the spring. Rope [...]

7.5 Section 7 Retract able St arter 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 sure the threads in the center shaft remain clean, dry , and free of grease and oil. 6. Apply a small amount of Loctite ® No. 271 to[...]

7.6 Section 7 Retract able St arter[...]

8.1 Section 8 Electrical System and Component s 8 Section 8 Electrical System and Component s This section covers the operation, service and repair of the electrical system components. Systems and components covered in this section are: • S p ark Plugs • Battery and Charging System • Electronic CD Ignition System (including SMART - SP ARK ™[...]

8.2 Section 8 Electrical System and Component s Normal: A plug t aken from an engine operating under normal conditions will have light tan or gray colored deposits. If the center electrode is not worn, a plug in this condition could be set to the proper gap and reused. Wet Fouled: A wet plug is caused by excess fuel or oil in the combustion chamber[...]

8.3 Section 8 Electrical System and Component s 8 2. Keep the cables, terminals, and external surfaces of the battery clean. A build-up of corrosive acid or grime on the external surfaces can cause the battery to self-discharge. Self-discharge occurs rapidly when moisture is present. 3. W ash the cables, terminals, and external surfaces with a mild[...]

8.4 Section 8 Electrical System and Component s The SMART -SP ARK ™ ignition system used on some models is an advanced version of the CD ignition system used on other CH engines. Its operation can be best understood by first understanding the standard system and how it works. Since both systems will continue in use, it is advantageous to underst [...]

8.5 Section 8 Electrical System and Component s 8 Figure 8-4. Capacitive Discharge (Fixed T iming) Ignition System. Kill Switch or ‘ ‘Off’ ’ Position of Key Switch Ignition Modules Sp ark Plug Magnet Flywheel (0.28/0.33 mm) 0.01 1/0.013 in. Air Gap L1 D1 C1 T1 P S Sp ark Plug L2 SCS Figure 8-5. Cap acitive Discharge Ignition Module Schemati[...]

8.6 Section 8 Electrical System and Component s Figure 8-6. Capacitive Discharge Ignition System with S p ark Advance. Power Source Pulse Generator Reset Circuit B+ (12 VDC) Red Y ellow To Semi-Conductor Switch Comp arator Delay Circuit Charge Pump Conditioning Circuit V+ (7.2V) Brown From Input Coil Green or Black Figure 8-7. Block Diagram - Sp ar[...]

8.7 Section 8 Electrical System and Component s 8 The pulse generated by the input coil of the ignition module (L1, Figure 8-5) is fed to the input of the conditioning circuit. The conditioning circuit shapes this pulse, putting it in a useable form for the additional circuits. This pulse st arts the charge pump, which charges a capacitor in a line[...]

8.8 Section 8 Electrical System and Component s c. If neither side is firing, recheck position of ignition switch and check for shorted kill lead. T est Procedure for SMART -SP ARK TM Ignition Systems The following procedures are provided for troubleshooting ignition problems on SMART -SP ARK ™ equipped engines. They will allow you to isolate and[...]

8.9 Section 8 Electrical System and Component s 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 line on the blower housing adjacent to the line on the screen. Accelerate to full throttle and watch for movement of the line on the screen relative to the line on the blower housing. If both[...]

8.10 Section 8 Electrical System and Component s 5. Check and/or adjust the ignition module air gap(s). An air gap of 0.28/0.33 mm (0.01 1/0.013 in.) must be maintained under all three legs of the ignition module(s). Checking/ adjusting should be performed with the parts at room temperature. a. If the module was not loosened or replaced, check that[...]

8.11 Section 8 Electrical System and Component s 8 terminal of the ground lead or the ground screw/bolt. Check the voltage with the key switch in both the “ST ART” and “RUN” positions. A minimum of 7.25 volts must be present. a. If correct voltage is not measured, connect black voltmeter lead directly to the negative (-) post of the battery[...]

8.12 Section 8 Electrical System and Component s Figure 8-12. 2. Check the SAM p art number , stamped on the side of the housing, and determine if you have an analog SAM (ASAM) or a digital SAM (DSAM). Follow sub-step a for an ASAM, and sub-step b for a DSAM. T o help identify Service Bulletin 233 lists DSAM p art numbers. a. ASAM only: Depress the[...]

8.13 Section 8 Electrical System and Component s 8 Battery Charging System General Most engines are equipped with a 15 or 20 amp regulated charging system. Some have a 25 amp regulated charging system. See Figure 8-14 for the 15/20/25 amp charging system diagram. Some engines utilize a 3 amp unregulated system with optional 70 watt lighting circuit[...]

8.14 Section 8 Electrical System and Component s 15/20/25 amp Regulated Charging System Figure 8-14. Wiring Diagram - 15/20/25 amp Regulated Battery Charging System. Figure 8-15. 15 amp St ator and Rectifier-Regulator . Figure 8-16. 20 amp St ator and Rectifier-Regulator .[...]

8.15 Section 8 Electrical System and Component s 8 Figure 8-17. 25 amp St ator and Rectifier-Regulators. Ground-T o-Kill Lead (White) Diode Key Switch Optional Oil Sentry TM Switch (Indicator Light) Optional Oil Sentry TM Switch (Shut down) 12 V . Battery Solenoid St arter Light s (Y ellow) (Black) 3 Amp/70 Watt Flywheel St ator Ignition Modules Sp[...]

8.16 Section 8 Electrical System and Component s Figure 8-19. 3 amp/70 W att S t ator . St ator The stator is mounted on the crankcase behind the flywheel. Follow the procedures in Section 9 - “Disassembly” and Section 1 1 - “Reassembly” if st ator replacement is necessary . Rectifier-Regulator The rectifier-regulator is mounted on the blow[...]

8.17 Section 8 Electrical System and Component s 8 3. Plug the tester into a 1 10 volt AC outlet supply and turn on the power switch. See Figure 8-22. The ‘‘POWER’ ’ light should be illuminated and one of the four status lights may be on as well. This does not represent the condition of the part. Figure 8-23. a. If the “OK” (green) ligh[...]

8.18 Section 8 Electrical System and Component s 6. Press the ‘‘TEST’ ’ button until a ‘‘click’’ is heard and then release. See Figure 8-23. Momentarily one of the four lights will illuminate indicating the p artial condition of the p art. a. If the ‘‘OK’ ’ (green) light comes on, disconnect the tester black lead attached to[...]

8.19 Section 8 Electrical System and Component s 8 Figure 8-28. 3. Plug the tester into a 1 10 volt AC outlet and turn on the power switch. The ‘ ‘POWER’ ’ light should be illuminated and one of the four status light s may be on as well. See Figure 8-22. This does not represent the condition of the part. 4. Press the ‘‘TEST’ ’ butto[...]

8.20 Section 8 Electrical System and Component s Problem T est 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 . Connect DC voltmeter from loose end of B+ lead to negative terminal[...]

8.21 Section 8 Electrical System and Component s 8 T roubleshooting Guide 3 amp Battery Charging System with 70 Watt Lighting S tator NOTE: Zero ohmmeters on each scale to ensure accurate readings. V oltage tests should be made with engine running at 3000 RPM - no load. Battery must be good and fully charged. Problem No Charge to Battery No Light s[...]

8.22 Section 8 Electrical System and Component s Electric St arting Motors Some engines in this series use inertia drive starting motors while most use solenoid shift starters. The inertia drive types are covered first and the solenoid shift types following. St arting Motor Precautions NOTE: Do not crank the engine continuously for more than 10 sec[...]

8.23 Section 8 Electrical System and Component s 8 Operation - Inertia Drive St arters When power is applied to the starter , the armature rotates. As the armature rotates, the drive pinion moves out on the splined drive shaft and into mesh with the flywheel ring gear . When the pinion reaches the end of the drive shaft, it rot ates the flywheel an[...]

8.24 Section 8 Electrical System and Component s 3. Again referring to Figure 8-31, grasp the spring retainer and push it toward the starter , compressing the anti-drift spring and exposing the retaining ring. 4. Holding the spring retainer in the retracted position, assemble the inner halves of the removal tool around the armature shaft with the r[...]

8.25 Section 8 Electrical System and Component s 8 Retaining Ring Inst allation 1. Position the retaining ring in the groove in one of the inner halves. Assemble the other half over the top and slide on the outer collar . 2. Be certain the drive components are inst alled in correct sequence onto the armature shaft. 3. Slip the tool over the end of [...]

8.26 Section 8 Electrical System and Component s NOTE: Use a brush holder tool to keep the brushes in the pockets. A brush holder tool can easily be made from thin sheet metal. See Figure 8-36. Figure 8-36. Brush Holder T ool (Style ‘ ‘A ’ ’ End Cap). Style ‘ ‘B’ ’ End Cap Brush Replacement S tarters with S tyle ‘ ‘B’ ’ end [...]

8.27 Section 8 Electrical System and Component s 8 Figure 8-38. Style ‘ ‘B’’ Commut ator End Cap with Brushes. 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 instructions for servicing the starter dri[...]

8.28 Section 8 Electrical System and Component s St arter Disassembly 1. Disconnect the lead wire from the solenoid. 2. Remove the hex. nuts securing the solenoid, and remove the solenoid from the starter assembly . 3. Remove the two thru bolts. 4. Remove the commutator end cap. 5. Remove the insulator and the brush springs from the brush spring ho[...]

8.29 Section 8 Electrical System and Component s 8 Figure 8-41. Removing Solenoid Screws. 3. If the solenoid was mounted with Phillips head screws, separate the solenoid and plunger spring from the drive end cap. If the solenoid was mounted with external T orx head screws, the plunger is part of the solenoid, unhook the plunger pin from the drive l[...]

8.30 Section 8 Electrical System and Component s Figure 8-44. Removing Thru Bolts. 5. Remove the commutator end plate assembly , containing the brush holder , brushes, springs, and locking caps. Remove the thrust washer from inside the commutator end. See Figure 8-45. Figure 8-45. Removing Commutator End Plate Assembly . 6. Remove the frame from th[...]

8.31 Section 8 Electrical System and Component s 8 Figure 8-50. Removing Retaining Ring. 12. Remove the drive pinion assembly from the armature. 13. Clean the part s as required. NOTE: Do not soak the armature or use solvent when cleaning. Wipe clean using a soft cloth, or use compressed air . Figure 8-49. Ret aining Ring Det ail. 1 1. Remove the r[...]

8.32 Section 8 Electrical System and Component s Figure 8-52. Checking Brushes. Armature 1. Clean and inspect the commutator (outer surface). The mica insulation must be lower than the commutator bars (undercut) to ensure proper operation of the commutator . See Figure 8-53. Figure 8-54. Checking Armature. 3. Check for continuity between the armatu[...]

8.33 Section 8 Electrical System and Component s 8 Figure 8-56. Service Brush Kit. 5. Perform S teps 10-13 in the “S t arter Reassembly” sequence. Installation must be done af ter the armature, drive lever , and frame are installed, if the starter has been disassembled. Brush Replacement The brushes and springs are serviced as a set (4). Use Br[...]

8.34 Section 8 Electrical System and Component s Figure 8-58. Installing Thrust W asher . 4. Apply a small amount of oil to the bearing in the drive end cap, and install the armature with the drive pinion. 5. Lubricate the fork end and center pivot of the drive lever with drive lubricant (Kohler Part No. 52 357 02-S ). Position the fork end into th[...]

8.35 Section 8 Electrical System and Component s 8 Figure 8-62. Installing Thrust W asher . 10. S t arter reassembly when replacing the Brushes/ Brush Holder Assembly: a. Hold the starter assembly vertically on the end housing, and carefully position the assembled brush holder assembly , with the supplied protective tube, against the end of the com[...]

8.36 Section 8 Electrical System and Component s Figure 8-66. Inst alling Brush Holder Assembly using T ool with Extension. 1 1. Install the end cap onto the armature and frame, aligning the thin raised rib in the end cap with the corresponding slot in the grommet of the positive (+) brush lead. 12. Inst all the two thru bolts, and the two brush ho[...]

9.1 Section 9 Disassembly 9 Section 9 Disassembly W ARNING: Accidental St arts! Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disconnect negative (-) battery cable from battery . CH18-745 19. Remove cylinder h[...]

9.2 Section 9 Disassembly Figure 9-2. Removing Dip stick from T ube. Figure 9-3. Removing Oil Fill Cap from Cover . Figure 9-6. Removing Oil Filter Adapter Nipple. Figure 9-4. Removing Oil Drain Plug. 2. Allow ample time for the oil to drain from the crankcase and oil filter . Figure 9-5. Removing Oil Filter . 3. Remove and discard the oil filter .[...]

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 cast aluminum housing, part of the oil filter adapter , or attached to the blower housing, sep arated from the oil filter adapter . If so equipped, remove the adapter and the cooler . See Figures 9[...]

9.4 Section 9 Disassembly Figure 9-1 1. Removing T ube from Breather Cover . 6. Remove the rubber breather tube from the breather cover . See Figure 9-1 1. Remove Fuel Pump W ARNING: Explosive Fuel! Gasoline is extremely flammable and its vapors can explode if ignited. Store gasoline only in approved containers, in well ventilated, unoccupied build[...]

9.5 Section 9 Disassembly 9 Figure 9-15. Removing Screws Holding Fuel Pump (Met al Bodied Pump Shown). 4. Note or mark the orientation of the fuel pump, then remove the fuel pump with lines attached as shown in Figure 9-16. Figure 9-16. Remove Fuel Pump and Lines. Mechanical Fuel Pump The mechanical style fuel pump is part of the valve cover assemb[...]

9.6 Section 9 Disassembly 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 . See Figure 9-21. Remove External Governor Con[...]

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 St arter Motor . 3. Remove the starter assembly and any spacers (if used). Remove Outer Baffles and Blower Housing 1. Disconnect the plug from the rectifier-regulator on the blower housing. See [...]

9.8 Section 9 Disassembly Figure 9-29. Removing the Sp ark Advance Module (Applicable Models). 4. Remove the three (each side) hex. flange screws securing the outer baffles. Note the location of any lifting strap and position of the two short screws (one each side on bottom) for reassembly . See Figure 9-30. Figure 9-31. Removing Outer Baffles. 5. [...]

9.9 Section 9 Disassembly 9 Figure 9-34. Removing Fasteners Holding Baffle and 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 protruding edge of the breather cover with a screwdriver[...]

9.10 Section 9 Disassembly 7. Remove the hex. flange screw , breather reed retainer and breather reed. See Figure 9-39. Figure 9-39. Removing Breather Reed. Remove V alve Covers Three valve cover designs have been used. The earliest type used a gasket and R TV sealant between the cover and sealing surface of the cylinder head. The second type had a[...]

9.11 Section 9 Disassembly 9 Figure 9-41. Disconnecting Leads from Ignition Modules. 2. Rotate the flywheel so the magnet is away from the modules. 3. Remove the mounting screws and ignition modules. Note the position of ignition modules. Figure 9-42. Position of SMART -SP ARK ™ Ignition Module. Remove Int ake Manifold 1. Remove the four hex. fla[...]

9.12 Section 9 Disassembly 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 should always be reinstalled in the same positions. 3. Carefully remove the push rods, cylinder heads and head gaskets. See Figure 9-47. Figure 9-45. Removing Sp ark Plugs. Remove[...]

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 lif ter bores. Use Hydraulic Lifter T ool (SPX Part No. KO1044) Do not use a magnet to remove lifters. Mark the lifters by location, as either intake or exhaust and cylinder 1 or 2. Hydraulic lifters sh[...]

9.14 Section 9 Disassembly Figure 9-53. V alve T rain Components. Figure 9-51. Removing Rocker Arms. 2. Compress the valve springs using a valve spring compressor . See Figure 9-52. Figure 9-52. Removing V alves with V alve S pring Compressor . Disassemble Cylinder Heads 1. Remove the two hex. flange screws, rocker arm pivots and rocker arms from t[...]

9.15 Section 9 Disassembly 9 Figure 9-55. Removing Plastic T ype 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 the hex. flange screw securing the flywheel to the crankshaft. See Fi[...]

9.16 Section 9 Disassembly Figure 9-63. Breaking Seal on T op S plitting T ab. Governor Gear Assembly The governor gear assembly is located inside the closure plate. If service is required, refer to the service procedures under ‘‘Governor Gear Assembly’’ in Section 10. Oil Pump Assembly The oil pump is mounted to the inside of the closure p[...]

9.17 Section 9 Disassembly 9 Figure 9-65. Removing Connecting Rod Bolt s. NOTE: If a carbon ridge is present at the top of either cylinder bore, use a ridge reamer tool to remove the ridge before attempting to remove the piston. Figure 9-64. Removing Camshaft (Note Shim). Remove Connecting Rods with Pistons and Rings 1. Remove the two hex. flange s[...]

9.18 Section 9 Disassembly 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 governor cross shaft. See Figures 9-69 and 9-70. Remove Crankshaf t 1. Carefully pull the crankshaft from the crankcase. See Figure 9-68. Note thrust washers and shims if use[...]

10.1 Section 10 Inspection and Reconditioning 10 Section 10 Inspection and Reconditioning This section covers the operation, inspection, and repair/reconditioning of major internal engine components. The following component s are not covered in this section. They are covered in sections of their own: Air Cleaner , Section 4 Carburetor & Externa[...]

10.2 Section 10 Inspection and Reconditioning Inspect the crankshaft bearing surfaces for scoring, grooving, etc. Some engines have bearing inserts in the crankshaft bore of the closure plate and/or crankcase. Do not replace bearings unless they show signs of damage or are out of running clearance specifications. If the crankshaft turns easily and [...]

10.3 Section 10 Inspection and Reconditioning 10 Check the cylinder bore wall for scoring. In severe cases, unburned fuel can cause scuffing and scoring of the cylinder wall. It washes the necessary lubricating oils off the piston and cylinder wall. As raw fuel seeps down the cylinder wall, the piston rings make metal to metal contact with the wall[...]

10.4 Section 10 Inspection and Reconditioning The final cleaning operation should always be a thorough scrubbing with a brush and hot, soapy water . Use a strong detergent that is capable of breaking down the machining oil while maintaining a good level of suds. If the suds break down during cleaning, discard the dirty water and start again with mo[...]

10.5 Section 10 Inspection and Reconditioning 10 EXHAUST VA LV E E G F H D D C A B A B A F E G H INT AKE V AL VE EXHAUST INSERT INT AKE INSERT A B C D E F G H Seat Angle Insert O.D. Guide Depth Guide I.D. V alve Head Diameter V alve Face Angle V alve Margin (Min.) V alve S tem Diameter Dimension 89° 36.987/37.013 mm (1.4562/1.4572 in.) 4 mm (0.157[...]

10.6 Section 10 Inspection and Reconditioning Normal: Even after long hours of operation a valve can be reconditioned and reused if the face and margin are in good shape. If a valve is worn to where the margin is less than 1/32" do not reuse it. The valve shown was in operation for almost 1000 hours under controlled test conditions. Bad Condit[...]

10.7 Section 10 Inspection and Reconditioning 10 Excessive Combustion T emperatures: The white deposits seen here indicate very high combustion temperatures, usually due to a lean fuel mixture. Gum: Gum deposits usually result from using st ale gasoline. Gum is a prevalent cause of valve sticking. The cure is to ream the valve guides and clean or r[...]

10.8 Section 10 Inspection and Reconditioning V alve Guides If a valve guide is worn beyond specifications, it will not guide the valve in a straight line. This may result in burnt valve faces or seats, loss of compression, and excessive oil consumption. T o check valve guide-to-valve stem clearance, thoroughly clean the valve guide and, using a sp[...]

10.9 Section 10 Inspection and Reconditioning 10 Ring failure is usually indicated by excessive oil consumption and blue exhaust smoke. When rings fail, oil is allowed to enter the combustion chamber where it is burned along with the fuel. High oil consumption can also occur when the piston ring end gap is incorrect because the ring cannot properly[...]

10.10 Section 10 Inspection and Reconditioning Piston Ring Piston Ring Expander Replacement pistons are available in STD bore size, and in 0.25 mm (0.010 in.), and 0.50 mm (0.020 in.) oversize. Replacement pistons include new piston ring sets and new piston pins. Replacement ring sets are also available separately for STD, 0.25 mm (0.010 in.), and [...]

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 ends of expander are not overlapped. 2. Middle Compression Ring (Center Groove): Install the center ring using a piston ring installation tool. Make sure the “identif[...]

10.12 Section 10 Inspection 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 the damaged shaft, press or lightly t ap the replacement shaft into the closure pla[...]

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. T orque the hex. flange screws as follows: First T ime Installation: 10.7 N·m (95 in. lb.) All Reinstallations: 6.7 N·m (60 in. lb.) 5. After torquing, rot ate the gear and check fo[...]

10.14 Section 10 Inspection and Reconditioning[...]

11.1 Section 1 1 Reassembly 11 Section 1 1 Reassembly General NOTE: Make sure the engine is assembled using all specified torque values, tightening sequences and clearances. Failure to observe specifications could cause severe engine wear or damage. Always use new gasket s. Make sure all traces of any cleaner are removed before the engine is assemb[...]

11.2 Section 1 1 Reassembly Figure 1 1-2. Inst alling Oil Seal. Inst all Governor Cross Shaf t 1. Lubricate the governor cross shaft bearing surfaces in the crankcase with engine oil. 2. Slide the small lower washer onto the governor cross shaft and install the cross shaf t from the inside of the crankcase. 3. 6 mm Governor Shaft: Install the plain[...]

11.3 Section 1 1 Reassembly 11 Figure 1 1-9. Installing Piston Assembly Using Ring Compressor T ool. 5. Install the inner rod cap to the connecting rod using the two hex. flange screws. Three dif ferent types of connecting rod bolts have been used and each has a different torque value. If 8 mm straight shank type bolts are used, torque in increment[...]

11.4 Section 1 1 Reassembly Figure 1 1-10. Connecting Rod Bolt s. Figure 1 1-12. Apply Camshaf t Lubricant to Cam Lobes. 2. Position the timing mark of the crankshaft gear at the 12 o’clock position. 3. T urn the governor cross shaf t clockwise until the lower end of the shaft cont act s the cylinder . Make sure the cross shaft remains in this po[...]

11.5 Section 1 1 Reassembly 11 Figure 1 1-14. Checking Camshaf t End Play . 3. Apply pressure on the camshaft end play checking tool (pushing camshaft toward crankshaft). Use a feeler gauge to measure the camshaft end play between the shim spacer and the checking tool. Camshaft end play should be 0.076/0.127 mm (0.003/0.005 in.) . 4. If the camshaf[...]

11.6 Section 1 1 Reassembly Remove the closure plate. If end play requires adjustment, remove the original spacer and inst all the appropriate size shim spacer in it s place. Then follow the procedure under “Install Closure Plate Assembly .” Inst all Closure Plate Oil Seal 1. Check to make sure that there are no nicks or burrs in the crankshaft[...]

11.7 Section 1 1 Reassembly 11 Figure 1 1-19. Closure Plate Sealant Pattern. 4. Make sure the end of the governor cross shaft is lying against the bottom of cylinder 1 inside the crankcase. See Figure 1 1-13. 5. Install the closure plate to the crankcase. Carefully seat the camshaft and the crankshaft into their mating bearings. Rotate the cranksha[...]

11.8 Section 1 1 Reassembly Inst all Flywheel W ARNING: Damaging Crankshaf t and Flywheel Can Cause Personal Injury! Using improper procedures to install the flywheel can crack or damage the crankshaft and/or flywheel. This not only causes extensive engine damage, but can also cause personal injury , since broken fragments could be thrown from the [...]

11.9 Section 1 1 Reassembly 11 Figure 1 1-29. Inst alling and T orquing Flywheel Fastener . Inst all Flywheel Fan 1. Install the fan onto the flywheel using the four hex. flange screws. NOTE: Position the ears located at rear perimeter of the fan in the recesses of the flywheel. See Figure 1 1-30. Figure 1 1-28. Carefully Align Keyway to Key . NOTE[...]

11.10 Section 1 1 Reassembly Inst all Supports for the Met al Grass Screen 1. If a metal grass screen is used, with threaded individual supports, install a sp acer washer on the external threads. Apply blue Loctite ® No. 242 (removable) onto the threads. Install the four supports as shown in Figure 1 1-32. Figure 1 1-32. Inst alling Support s for [...]

11.11 Section 1 1 Reassembly 11 Figure 1 1-36. Match Numbers on Cylinder Barrel and Head. Figure 1 1-38. V alve Component s. Intake V alve Seal V alve Keepers Ret ainer Spring Cap Figure 1 1-39. Inst alling V alves with V alve Spring Compressor . Inst all Cylinder Heads NOTE: Cylinder heads must be attached with the original type of mounting hardwa[...]

11.12 Section 1 1 Reassembly Figure 1 1-41. T orquing Cylinder Head Fasteners. Figure 1 1-42. Cylinder Head Fastener T orque Sequence. Heads secured with mounting studs, nut s, and washers: 2. If all of the studs were left int act, go to S tep 6. If any studs were disturbed or removed, install new studs as described in S tep 3. Do not use/reinstall[...]

11.13 Section 1 1 Reassembly 11 Figure 1 1-43. Installing New Mounting S tuds to Specified 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 Figure 1 1-36. Make sure the head is flat on the gasket and do[...]

11.14 Section 1 1 Reassembly 5. Repeat the above steps for the remaining cylinder . Do not interchange parts from the cylinder heads. Figure 1 1-47. Using S p anner W rench to Lif t Rocker Arm Over Push Rod. 6. Rot ate the crankshaft to check for free operation of the valve train. Check the clearance between the valve spring coils at full lift. Min[...]

11.15 Section 1 1 Reassembly 11 Figure 1 1-50. Setting Ignition Module Air Gap. 6. T orque 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 ignition modules. Make sure the magnet does not strike the modules. Check the [...]

11.16 Section 1 1 Reassembly Figure 1 1-56. Installing Breather Reed Assembly . 4. Insert the breather filter into position in the crankcase. Make sure no filter strands are on the sealing surface. See Figure 1 1-57. 5. Install the new breather gasket. Figure 1 1-54. Connecting Kill Leads on St andard Ignition Modules. Figure 1 1-55. Connect Leads [...]

11.17 Section 1 1 Reassembly 11 Figure 1 1-58. Inst alling Screws (Locations 3 and 4). 7. Install the inner baf fles using the two remaining hex. flange screws (see Figures 1 1-59 and 1 1-60) and finger tighten. Do not torque the screws at this time; they will be tightened after the blower housing and outer baffles are inst alled. Figure 1 1-59. In[...]

11.18 Section 1 1 Reassembly Figure 1 1-65. Tighten Baffle Mounting Screws. 6. The metal grass screen can now be attached to the supports. Figure 1 1-64. Tighten Short Screws to T orque Specified. Figure 1 1-66. Inst alling Met al T ype Grass Screen. 7. T orque the four breather cover screws to 7.3 N·m (65 in. lb.) in the sequence shown in Figure [...]

11.19 Section 1 1 Reassembly 11 Figure 1 1-67. Breather Cover Fastener T orque Sequence. Reconnect Rectifier-Regulator 1. Install the rectifier-regulator in the blower housing, if removed previously , then connect the rectifier- regulator ground lead with the washer and silver screw through the eyelet as shown in Figure 1 1-68. If a grounding brack[...]

11.20 Section 1 1 Reassembly Figure 1 1-71. Reinst alling SAM Module. Inst all Electric St arter Motor 1. Install the starter motor using the two hex. flange screws. See Figure 1 1-72. Some inertia-drive starters have a pinion cover and sp acers on the st arter bolts. 2. T orque the two hex. flange screws to 15.3 N·m (135 in. lb.) . Figure 1 1-72.[...]

11.21 Section 1 1 Reassembly 11 Figure 1 1-74. Reinst alled Fuel Pump. Inst all Carburetor W ARNING: Explosive Fuel! Gasoline may be present in the carburetor and fuel system. Gasoline is extremely flammable and its vapors can explode if ignited. Keep sparks and other sources of ignition away from the engine. 1. Install a new carburetor gasket. Mak[...]

11.22 Section 1 1 Reassembly Figure 1 1-78. 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 1 1-79. Figure 1 1-79. Holding and T ightening Governor Arm. 5. Reconnect the lead wire to the fuel shut[...]

11.23 Section 1 1 Reassembly 11 Figure 1 1-82. Connecting Spring to Governor Lever . 3. Connect the governor spring from the main control bracket to the appropriate hole in the governor lever as indicated in the following charts. Note that hole positions are counted from the pivot point of the governor lever . See Figure 1 1-82 and the appropriate [...]

11.24 Section 1 1 Reassembly 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 3 3 3 2 2 1 1 1 1 Governor Shaf t Configuration Needle Bearing St andard (Parent Mate[...]

11.25 Section 1 1 Reassembly 11 Figure 1 1-83. Throttle/Choke Control Bracket Det ail. Inst all Oil Sentry ™ (If So Equipped) 1. Apply pipe sealant with T eflon ® (Loctite ® No. 59241 or equivalent) to the threads of the Oil Sentry ™ switch and install it into the breather cover . See Figure 1 1-84. T orque to 4.5 N·m (40 in. lb.) . 2. Conne[...]

11.26 Section 1 1 Reassembly Inst all V alve Covers Three valve cover designs have been used. The earliest type used a gasket and RTV sealant between the cover and sealing surface of the cylinder head. The second type had a black O-Ring installed in a groove on the underside of the cover and may have metal spacers in the bolt holes. The newest desi[...]

11.27 Section 1 1 Reassembly 11 Figure 1 1-87. Connecting Fuel Inlet Line. 2. Position a new gasket and the air cleaner base while carefully pulling the loose end of the rubber breather hose through the base until properly seated (collars sealed against each side of base). See Figure 1 1-88. Figure 1 1-88. Pulling Breather Hose through Base. NOTE: [...]

11.28 Section 1 1 Reassembly Figure 1 1-92. T orquing Oil Filter Nipple. Inst all Oil Cooler 1. Reinstall the oil cooler on the engine (if equipped). Install a new gasket between the cooler and the closure plate. T orque nipple adapter to 27 N·m (20 f t. lb.) . See Figure 1 1-92. Figure 1 1-93. Inst alling New Oil Filter . 3. Hand tighten the filt[...]

11.29 Section 1 1 Reassembly 11 Figure 1 1-96. Reinstall the Dip stick in T ube. 6. Make sure the O-Ring is in place then reinstall the oil fill cap on the valve cover . See Figure 1 1-97. Figure 1 1-97. Reinst alling Oil Fill Cap (Some Models). Connect Sp ark Plug Leads 1. Connect the leads to the spark plugs. See Figure 1 1-98. Figure 1 1-98. Con[...]

11.30 Section 1 1 Reassembly[...]

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 T ype Clutch - Exploded View . Nameplate Gasket Shifting Lever Seal Shaft (Y oke) Clutch Housing Key Y oke Roll Pin Ball Bearing Power Shaf t Adjusting Ring Dr[...]

12.2 Section 12 Clutch Service On this type, an oil “splash” type lubrication system is used. The proper oil level must be maintained to provide efficient lubrication. The oil should be changed after each 100 hours of operation. When refilling, use 0.47 L (1 pt.) of motor oil of proper viscosity . See chart below . 2. After adjustment is made, [...]

LITHO IN U.S.A. FORM NO.: TP-2428-B ISSUED: 4/92 R EV I SE D : 6/04 MAILED: 7/04 ENGINE DIVISION, KOHLER CO., KOHLER, WISCONSIN 53044 FOR SALES AND SERVICE INFORMA TION IN U.S. AND CANADA, CALL 1-800-544-2444[...]