Kohler Command CH18-750 Service Manual
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Kohler Command CH18-750 Service Manual

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ERVICE
ANUAL
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CH18-750
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ORIZONTAL
RANKSHAFT

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Summary of Contents for Kohler Command CH18-750

  • Page 1 ERVICE ANUAL COMMAND CH18-750 ORIZONTAL RANKSHAFT...
  • Page 2 Contents Section 1. Safety and General Information ................Section 2. Special Tools ......................Section 3. Troubleshooting ..................... Section 4. Air Cleaner and Air Intake System ................ Section 5. Fuel System and Governor ..................Section 5A. LPG Fuel Systems ....................Section 5B. Electronic Fuel Injection (EFI) Fuel System ............Section 6.
  • Page 3 Section 1 Safety and General Information Section 1 Safety and General Information Safety Precautions To ensure safe operation please read the following statements and understand their meaning. Also refer to your equipment manufacturer's manual for other important safety information. This manual contains safety precautions which are explained below.

  • Page 4: Section 1 Safety And General Information

    Section 1 Safety and General Information WARNING WARNING WARNING Explosive Gas can cause fires and Explosive Fuel can cause fires and Carbon Monoxide can cause severe severe acid burns. severe burns. nausea, fainting or death. Charge battery only in a well Do not fill the fuel tank while the Avoid inhaling exhaust fumes, and ventilated area.
  • Page 5 Section 1 Safety and General Information Engine Identification Numbers When ordering parts, or in any communication involving an engine, always give the Model, Specification and Serial Numbers, including letter suffixes if there are any. The engine identification numbers appear on a decal, or decals, affixed to the engine shrouding.
  • Page 6 SAE viscosity grade. See Figure 1-3. Gasoline/Alcohol blends Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline by volume) is approved as a fuel for Kohler engines. Other gasoline/alcohol blends are not approved. Gasoline/Ether blends Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blends (up to a maximum of 15% MTBE by volume) are approved as a fuel for Kohler engines.
  • Page 7 ¹Perform these maintenance procedures more frequently under extremely dusty, dirty conditions. ²Only requried for Denso starters. Not necessary on Delco starters. Have a Kohler Engine Service Dealer perform this service. ³Cleanout Kits 25 755 20-S (black) or 25 755 21-S (gold) allow cooling areas to be cleaned without removing shrouds.
  • Page 8 Section 1 Safety and General Information Dimensions in millimeters. Inch equivalents shown in [ ]. Figure 1-4. Typical Engine Dimensions CH Series with Standard Flat Air Cleaner.
  • Page 9 Section 1 Safety and General Information Dimensions in millimeters. Inch equivalents shown in [ ]. Figure 1-5. Typical Engine Dimensions CH EFI Series with Heavy-Duty Air Cleaner.
  • Page 10 Section 1 Safety and General Information General Specifications¹ Power (@ 3600 RPM, exceeds Society of Automotive Engineers-Small Engine Test Code J1940.) CH18 ............................13.4 kW (18 HP) CH20 ............................14.9 kW (20 HP) CH22 ............................16.4 kW (22 HP) CH23 ............................17.2 kW (23 HP) CH25, CH730 ..........................
  • Page 11 Section 1 Safety and General Information General Specifications¹ cont. Angle of Operation - Maximum (At Full Oil Level) All Directions ....25° Blower Housing and Sheet Metal M5 Fasteners Torque ....................6.2 N·m (55 in. lb.) into new holes 4.0 N·m (35 in. lb.) into used holes M6 Fasteners Torque ....................
  • Page 12 Section 1 Safety and General Information Crankcase Governor Cross Shaft Bore I.D. 6 mm Shaft New ........................6.025/6.050 mm (0.2372/0.2382 in.) Max. Wear Limit ..................... 6.063 mm (0.2387 in.) 8 mm Shaft New ........................8.025/8.075 mm (0.3159/0.3179 in.) Max. Wear Limit ..................... 8.088 mm (0.3184 in.) Breather Cover Fastener Torque ................
  • Page 13 Section 1 Safety and General Information Crankshaft cont. Crankshaft T.I.R. PTO End, Crank in Engine ................0.279 mm (0.0110 in.) Entire Crank, in V-Blocks ................0.10 mm (0.0039 in.) Cylinder Bore Cylinder Bore I.D. New - CH18, CH20, CH22 (624 cc) ............... 77.000/77.025 mm (3.0315/3.0325 in.) New - CH22/23 (674 cc) .................
  • Page 14 Section 1 Safety and General Information Ignition ® Spark Plug Type (Champion or Equivalent) ............. RC12YC, XC12YC, or Platinum 3071 Spark Plug Gap ....................... 0.76 mm (0.030 in.) Spark Plug Torque ....................24.4-29.8 N·m (18-22 ft. lb.) Ignition Module Air Gap ..................0.28/0.33 mm (0.011/0.013 in.) Ignition Module Fastener Torque .................
  • Page 15 Section 1 Safety and General Information Piston, Piston Rings, and Piston Pin cont. Top and Center Compression Ring End Gap New Bore - CH18, CH20, CH22 (624 cc) ............0.25/0.45 mm (0.0098/0.0177 in.) New Bore - CH22/23 (674 cc) ................ 0.18/0.46 mm (0.0071/0.0181 in.) New Bore - CH25, CH26, CH730-745 ............
  • Page 16 Section 1 Safety and General Information Valve Cover Valve Cover Fastener Torque Gasket Style Cover ....................3.4 N·m (30 in. lb.) Black O-Ring Style Cover w/Shoulder Screws ..................5.6 N·m (50 in. lb.) w/Flange Screws and Spacers ..............9.9 N·m (88 in. lb.) Yellow or Brown O-Ring Style Cover w/Integral Metal Spacers ....
  • Page 17 Section 1 Safety and General Information General Torque Values Metric Fastener Torque Recommendations for Standard Applications Tightening Torque: N·m (in. lb.) + or - 10% Property Class Noncritical Fasteners Into Aluminum 10.9 12.9 Size 1.2 (11) 1.7 (15) 2.9 (26) 4.1 (36) 5.0 (44) 2.0 (18)
  • Page 18 Section 1 Safety and General Information English Fastener Torque Recommendations for Standard Applications Tightening Torque: N·m (in. lb.) + or - 20% Bolts, Screws, Nuts and Fasteners Grade 2 or 5 Assembled Into Cast Iron or Steel Fasteners Into Aluminum Grade 2 Grade 5 Grade 8...
  • Page 19 By using tools designed for the job, you can properly service engines easier, faster, and safer! In addition, you’ll increase your service capabilities and customer satisfaction by decreasing engine downtime. Here is the list of tools and their source. Separate Tool Suppliers: Kohler Tools SE Tools Design Technology Inc. Contact your source 768 Burr Oak Drive 415 Howard St.
  • Page 20 Section 2 Tools & Aids ) . t . l a t f i l l a c i l f i l . s r i t i & . s t l i o i f i i f i i f i .
  • Page 21 Section 2 Tools & Aids - l e ) t f i l i ® e t i . r e l i o s i s , s t s i l ® e t i s i r c i t e t i ®...
  • Page 22 4. Use a flat washer with the correct I.D. to slip on tooth segment of the ring gear as shown. the capscrew and approximately 1” O.D. (Kohler Part No. 12 468 05-S). Assemble the capscrew 2. Grind off any burrs or sharp edges.
  • Page 23 Section 3 Troubleshooting Section 3 Troubleshooting Troubleshooting Guide 10. Diode in wiring harness failed in open circuit mode. When troubles occur, be sure to check the simple causes which, at first, may seem too obvious to be Engine Starts Hard considered.

  • Page 24: Section 3 Troubleshooting

    Section 3 Troubleshooting Engine Will Not Idle Engine Uses Excessive Amount of Oil 1. Dirt or water in the fuel system. 1. Incorrect oil viscosity/type. 2. Stale fuel and/or gum in carburetor. 2. Clogged or improperly assembled breather. 3. Faulty spark plugs. 3.
  • Page 25 Section 3 Troubleshooting To test the crankcase vacuum with the manometer: • Check the condition of the oil. Drain the oil into a container - the oil should flow freely. Check for 1. Insert the stopper/hose into the oil fill hole. Leave metal chips and other foreign particles.
  • Page 26 Section 3 Troubleshooting No Crankcase Vacuum/Pressure in Crankcase Solution Possible Cause 1. Disassemble breather, clean parts thoroughly, 1. Crankcase breather clogged or inoperative. check sealing surfaces for flatness, reassemble, and recheck pressure. 2. Replace all worn or damaged seals and gaskets. 2.
  • Page 27 Section 3 Troubleshooting Leakdown Test Results Air escaping from crankcase breather ............Defective rings or worn cylinder. Air escaping from exhaust system .............. Defective exhaust valve/improper seating. Air escaping from carburetor ............... Defective intake valve/improper seating. Gauge reading in “low” (green) zone ............Piston rings and cylinder in good condition.
  • Page 28 Section 4 Air Cleaner and Air Intake System Air Cleaners General Most engines are equipped with a replaceable, high- density paper air cleaner element, surrounded by an oiled foam precleaner, and housed under a flat outer cover. This is typically referred to as the standard air cleaner assembly.

  • Page 29: Section 4 Air Cleaner And Air Intake System

    4. Do not wash the paper element or use pressurized air, as this will damage the element. Replace a dirty, bent, or damaged element with a genuine Kohler element. Handle new elements carefully; do not use if the sealing surfaces are bent or damaged.
  • Page 30 Section 4 Air Cleaner and Air Intake System 5. Check the seal for any damage or deterioration. 7. Reinstall the air cleaner cover and secure with the Replace as necessary. See Figure 4-7. latches or the retaining knob. 6. Reinstall the seal, paper element, precleaner, NOTE: Make sure the correct depth air cleaner element cover, and wing nut.
  • Page 31 Section 4 Air Cleaner and Air Intake System Air Cleaner Element Cover and Seal - Make sure element cover is not bent or damaged. Make sure the wing nut and seal are in place to ensure the element is sealed against leakage. Air Cleaner Base - Make sure the base is secured tightly to the carburetor and not cracked or damaged.
  • Page 32 4. Do not wash the paper element and inner element or use compressed air, this will damage the elements. Replace dirty, bent or damaged elements with new genuine Kohler elements as required. Handle the new elements carefully; do not use if the sealing surfaces are bent or damaged.
  • Page 33 Section 4 Air Cleaner and Air Intake System *Cleanout kits, Kohler Part No. 25 755 20-S (black) or 25 755 21-S (gold), are recommended to aid inspection and cleanout of the cooling fins. See Figure 4-15. NOTE: Operating the engine with a blocked grass...
  • Page 34 Gasohol (up to 10% ethyl alcohol, 90% unleaded equipped with a fuel pump, the fuel tank outlet is gasoline by volume) is approved as a fuel for Kohler located above the carburetor inlet allowing gravity to engines. Other gasoline/alcohol blends are not feed fuel to the carburetor.

  • Page 35: Section 5 Fuel System And Governor

    Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blends (up to a maximum of 15% MTBE by IMPORTANT ENGINE INFORMATION volume) are approved as a fuel for Kohler engines. THIS ENGINE MEETS U.S. EPA AND CA 2005 AND LATER AND EC STAGE II (SN:4) EMISSION Other gasoline/ether blends are not approved.
  • Page 36 Section 5 Fuel System and Governor Fuel System Tests When the engine starts hard, or turns over but will not start, it is possible that the problem is in the fuel system. To find out if the fuel system is causing the problem, perform the following tests. Troubleshooting –...
  • Page 37 Section 5 Fuel System and Governor NOTE: On most models, the pulse line is Fuel Pump connected to a fitting on the crankcase, while on early models, it is connected to General the valve cover. These engines are equipped with either a pulse or mechanical fuel pump.
  • Page 38 Section 5 Fuel System and Governor Carburetor WARNING: Explosive Fuel Gasoline is extremely flammable and its vapors can explode if General ignited. Store gasoline only in approved containers, in well Engines in this series are equipped with Keihin fixed ventilated, unoccupied buildings, away from sparks or flames. main jet carburetors.
  • Page 39 Section 5 Fuel System and Governor Troubleshooting Checklist When current is removed the pin extends blocking When the engine starts hard, runs roughly or stalls at the main fuel jet and preventing fuel from entering low idle speed, check the following areas before the carburetor.
  • Page 40 Section 5 Fuel System and Governor Carburetor Adjustments (CH18-740) NOTE: Carburetor adjustments should be made only after the engine has warmed up. General Adjusting Low Idle Speed and Fuel (Some Models) In compliance with government emission standards, To adjust the carburetor idle speed, see Figure 5-5 and the carburetor is calibrated to deliver the correct air- follow these steps.
  • Page 41 Section 5 Fuel System and Governor Models with Governed Idle System An optional governed idle control system is supplied on some engines. The purpose of this system is to maintain a desired idle speed regardless of ambient conditions (temperature, parasitic load, etc.) that may Hold Throttle change.
  • Page 42 Section 5 Fuel System and Governor NOTE: The fuel inlet needle tip is spring loaded. 2. Remove the four screws and carefully separate Make sure the float assembly rests the air horn assembly from the carburetor body. against the fuel inlet needle without depressing the tip.
  • Page 43 Section 5 Fuel System and Governor NOTE: The choke and throttle plate assemblies air horn. Tighten the screw. Check float height are staked and matched to the shafts at using the procedure found previously in the the factory. They are not serviceable ‘‘Adjustments’’...
  • Page 44 Section 5 Fuel System and Governor Components such as the throttle and choke shaft Slow & Mid-Range Circuit: assemblies, throttle plate, choke plate, low idle fuel At low speeds the engine operates only on the slow needle, and others, are available separately. circuit.
  • Page 45 Section 5 Fuel System and Governor 2. Place the throttle control into the “idle” or *NOTE: Engines operating at altitudes above “slow” position. Adjust the low idle speed to approximately 1500 m (5000 ft.) may require 1200 RPM*. Follow the “Adjusting the Low Idle a special ‘‘high altitude’’...
  • Page 46 Section 5 Fuel System and Governor 1. Make any necessary speed or control Carburetor Servicing adjustments following the appropriate instructions covered in this section. Float Replacement If symptoms described in the carburetor 2. Move the throttle control to the idle position. troubleshooting guide indicate float level problems, Hold the governor lever away from the remove the carburetor from the engine to check and/...
  • Page 47 Section 5 Fuel System and Governor 3. Remove the float pin screw and lift out the old float, pin and inlet needle. See Figure 5-17. Discard all of the parts. The seat for the inlet needle is not serviceable, and should not be removed.
  • Page 48 Section 5 Fuel System and Governor 9. When the proper float height is obtained, NOTE: Further disassembly of the fuel bowl is not carefully reinstall the fuel bowl, using new necessary unless the Fuel Solenoid Kit, or O-Rings onto the carburetor. Secure with the Fuel Bowl Kit (obtained separately), will also four original screws.
  • Page 49 Section 5 Fuel System and Governor 6. Clean the carburetor body, main jets, vent ports, 4. Remove the screw securing the flat washer and seats, etc. using a good commercially available ground lead (if equipped), from the top of the carburetor solvent.
  • Page 50 Section 5 Fuel System and Governor Figure 5-30. Installing Float Assembly. Figure 5-28. Installing Idle Speed Adjusting Screw and Spring. 14. Hold the carburetor body so the float assembly hangs vertically and rests lightly against the fuel 12. Attach the inlet needle to the plastic tang of the inlet needle.
  • Page 51 Section 5 Fuel System and Governor 16. When the proper float height is obtained, 5. Use a screw extractor (easy-out) and remove the carefully reinstall the fuel bowl, using new original choke shaft bushing with the old choke O-Rings onto the carburetor. Secure with the lever from the carburetor housing.
  • Page 52 Section 5 Fuel System and Governor 9. Install the new return spring onto the new choke shaft, so the upper leg of the spring is between the two formed “stops” on the end of the choke shaft. See Figure 5-36. NOTE: Make sure it stays in this location during the following step.
  • Page 53 Section 5 Fuel System and Governor 1. Carburetor Body Subassembly 2. Idle Speed Screw 3. Idle Speed Spring 4. Screw 5. Ground Lead 6. Retaining Washer 7. Slow Jet - RH Side 8. Slow Jet - LH Side 9. O-Ring (Slow Jet) (2) 10.
  • Page 54 Section 5 Fuel System and Governor Governor • When load is applied and the engine speed and governor gear speed decreases, the governor spring tension moves the governor arm to open General the throttle plate wider. This allows more fuel The governor is designed to hold the engine speed into the engine, increasing the engine speed.
  • Page 55 Section 5 Fuel System and Governor Sensitivity Adjustment High Speed (RPM) Adjustment (Refer to Figure 5-41.) Governor sensitivity is adjusted by repositioning the 1. With the engine running, move the throttle governor spring in the holes of the governor lever. If control to fast.
  • Page 56 Section 5 Fuel System and Governor Electronic Governor Governor Control Unit (GCU) senses engine speed by pulse voltage inputs from the ignition modules. The GCU regulates the engine speed by variable input General voltage from a customer-supplied potentiometer or a The electronic governor regulates engine speed at single pole, single throw (SPST) switch.
  • Page 57 Section 5 Fuel System and Governor Troubleshooting Procedure Engine does not run at the expected speed 1. Check to see that the throttle linkage and DLA Engine starts, but will not continue to run have full range of motion having no mechanical 1.
  • Page 58 Section 5A LPG Fuel Systems Section 5A LPG Fuel Systems WARNING: Explosive Fuel! LPG is extremely flammable, is heavier than air, and tends to settle in low areas where a spark or flame could ignite the gas. Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger the safety of persons in the area.
  • Page 59 Section 5A LPG Fuel Systems Operation 4. Insufficient vacuum signal, regulator not opening. a. Vacuum line between carburetor and In a liquid withdrawal system, the Liquefied regulator cracked, leaking, kinked, or pinched. Petroleum Gas (LPG) is released from the bottom of b.
  • Page 60 Section 5A LPG Fuel Systems LPG Carburetor Adjustments Engine stalls during operation 1. No fuel. 2. Faulty lock-off or blocked filter. General 3. Improper governor setting. The LPG carburetor and regulator are designed to 4. Damaged diaphragms within regulator. deliver the correct fuel-to-air mixture to the engine 5.
  • Page 61 Section 5A LPG Fuel Systems High Altitude Operation Impco Carburetor The standard carburetor calibrations will provide 1. Turn off fuel supply at tank. proper operation up to altitudes of 1500 m (5000 ft.). 2. Remove the air cleaner, breather hose, fuel line, No internal changes are necessary or available for either carburetor.
  • Page 62 See Figure 5A-6. Replace with a new Remove the nuts, carburetor, and gaskets from Kohler high pressure hose (LP rated) if the the engine. Discard the gaskets. condition is questionable in any way. Secure new hose using new clamps.
  • Page 63 Section 5A LPG Fuel Systems LPG Carburetor - Reassembly Idle Speed Clamp Bracket Position 1. Counting the number of turns, back the idle Impco Carburetor speed adjustment screw off (counterclockwise), 1. Slide the venturi into the carburetor body, so only 1 to 1 1/2 of the threads are visible. See aligning the position mark made prior to Figure 5A-8.
  • Page 64 Section 5A LPG Fuel Systems 3. Insert a 0.025 mm (0.001 in.) feeler gauge between the side of the stop collar and the carburetor housing, then check or set the position of the stop collar. The head of the mounting screw must be in contact with the carburetor boss from the back (hose/fitting) side, preventing any further rotation over center.
  • Page 65 Cleaning of the filter element is Secure base with two mounting nuts. Torque nuts to 9.9 N·m (88 in. lb.). Install the rest of the air not recommended. Order a replacement filter element by the appropriate Kohler part number. cleaner system. 5A.8...
  • Page 66 Section 5A LPG Fuel Systems Vaporizer Assembly The outer surface of the vaporizer should be kept free of dirt and debris accumulation, which will cause a loss of vaporization efficiency. Visual inspection and necessary cleaning should be performed on a regular basis, more frequently under dusty or dirty conditions.
  • Page 67 Section 5A LPG Fuel Systems Impco (Beam) Regulator (See Figure 5A-20) LPG vapor enters at point (A), then passes into primary area (B) at point (28), where pressure is reduced from up to 250 psi at the tank to 4.5 psi in area (B).
  • Page 68 Section 5A LPG Fuel Systems Nikki Regulator Primary Chamber Nikki Regulator Secondary Chamber (See Figure 5A-21) (See Figure 5A-22) The primary chamber reduces the high pressure fuel The secondary chamber further reduces the fuel pressure from the 29 kPa (4 psi) of the primary flow from the tank and vaporizer down to approximately 4 psi.
  • Page 69 LP personnel only. Impco (Beam) Regulator Service Kohler repair kit 24 757 40-S should be used to service the regulator every 1500 hours, or whenever cleaning and servicing is required. Nikki Regulator Service Kohler repair kit 24 757 39-S should be used every 1500 hours.

  • Page 70: Table Of Contents

    Section 5B EFI Fuel System Section 5B Electronic Fuel Injection (EFI) Fuel System Contents Page(s) Description Initial Starting/Priming Procedure ........................5B.2 Fuel Recommendations ............................5B.2 EFI Fuel System Components ..........................5B.3 Operation ................................5B.3 Important Service Notes ............................5B.4 Electrical Components Electronic Control Unit (ECU) ........................

  • Page 71: Description

    Section 5B EFI Fuel System Description a. Turn the key switch to the “on/run” position. The fuel pump will run for about three seconds and stop. Turn the switch off WARNING and back on to restart the fuel pump. Repeat this procedure until the fuel pump has cycled five times, then start the engine.

  • Page 72: Efi Fuel System Components

    Gasohol (up to 10% ethyl alcohol, 90% unleaded length of time that the injectors are “on.” This can gasoline by volume) is approved as a fuel for Kohler range from 1.5-8.0 milliseconds depending on fuel EFI engines. Other gasoline/alcohol blends are not requirements.

  • Page 73: Important Service Notes

    Section 5B EFI Fuel System Important Service Notes! Electrical Components • Cleanliness is essential and must be maintained at all times when servicing or working on the EFI Electronic Control Unit (ECU) system. Dirt, even in small quantities, can cause significant problems.

  • Page 74: Engine Speed Sensor

    Section 5B EFI Fuel System Three different styles of ECU’s have been utilized in EFI To prevent engine over-speed and possible failure, a production. The first style is easily identified by its “rev-limiting” feature is programmed into the ECU. If metal case with large 35 pin connector block, and also the maximum RPM limit (4125 RPM on MA 1.7, 4500 as MA 1.7.
  • Page 75 Section 5B EFI Fuel System General 6. Disconnect the speed sensor connector from The engine speed sensor is essential to engine wiring harness. It is the connector with one heavy operation; constantly monitoring the rotational speed black lead (see Figure 5B-5). Viewing the (RPM) of the crankshaft.
  • Page 76 Section 5B EFI Fuel System Mounted on the throttle body/intake manifold and Throttle Position Sensor (TPS) operated directly off the end of the throttle shaft, the TPS works like a rheostat, varying the voltage signal to the ECU in direct correlation to the angle of the throttle plate.
  • Page 77 Section 5B EFI Fuel System 4. Leave the leads connected to the pin terminals as 7. Remove the two mounting screws from the TPS. described in step 3. Rotate the throttle shaft Save the screws for reuse. Remove and discard slowly counterclockwise to the full throttle the faulty TPS.
  • Page 78 Section 5B EFI Fuel System “24 Pin” (MSE 1.0) Plastic-Cased ECU: Connect a b. If light stays on or blinking ceases jumper wire from the TPS initialization pin #24 prematurely, the procedure was unsuccessful (violet wire) to the battery voltage pin (red wire), and must be repeated.

  • Page 79: Engine (Oil) Temperature Sensor

    Section 5B EFI Fuel System 5. Remove the jumper wire or plug from the service Engine (Oil) Temperature Sensor connector plug in wiring harness. 6. Run the engine at full throttle (above 3000 RPM), to warm up the engine and initiate O sensor function in “closed-loop”...

  • Page 80: Oxygen Sensor

    Section 5B EFI Fuel System “24 Pin” (MSE 1.0) Plastic-Cased ECU: Check The tip of the sensor, protruding into the exhaust gas, between the #6 and #4 pin terminals. is hollow (see cutaway Figure 5B-12). The outer portion of the tip is surrounded by the exhaust gas, “32 Pin”...
  • Page 81 Section 5B EFI Fuel System 1. Oxygen sensor must be hot (minimum of 400°C, previous checkpoint. For example, if the reading 725°F). Run engine for about 5 minutes. With the is too low at points on the crankcase, but correct engine running, disconnect the oxygen sensor lead voltage is indicated when the black lead is from the wiring harness.

  • Page 82: Electrical Relay

    Section 5B EFI Fuel System a. If there is no continuity displayed in either of Electrical Relay the tests, check the harness circuit for breaks or damage, and the connections for poor contact, moisture, or corrosion. If no continuity was found in the first test, also check for a poor/broken ground path back through the exhaust system, engine, and mounting (sensor is grounded through its...

  • Page 83: Fuel Injectors

    Section 5B EFI Fuel System 6. Attach ohmmeter leads to the #30 and #87 Terminal #85 - Terminal #87 - terminals in relay. Initially, there should be no Feed To Ignition Ignition Switch continuity. Using a 12 volt power supply, connect Coils, Fuel Voltage the positive (+) lead to the #85 terminal, and touch...
  • Page 84 Section 5B EFI Fuel System When the key switch is on and the relay is closed, the Service fuel rail is pressurized, and voltage is present at the Injector problems typically fall into three general injector. At the proper instant, the ECU completes the categories: electrical, dirty/clogged, or leakage.
  • Page 85 Section 5B EFI Fuel System Check all electrical connections, connectors, and wiring harness leads if resistance is incorrect. Injector leakage is very unlikely, but in those rare instances it can be internal (past the tip of the valve needle), or external (weeping around the injector body).

  • Page 86: Ignition System

    Section 5B EFI Fuel System injector clogging include higher than normal 8. Thoroughly clean the area around and including the throttle body/manifold and the injectors. operating temperatures, short operating intervals, and dirty, incorrect, or poor quality fuel. Cleaning of clogged injectors is not recommended; they should be 9.

  • Page 87: Spark Plugs

    EFI engines are equipped with Champion RC12YC between terminal #87 and pin #1 for coil #1. (Kohler Part No. 12 132 02-S) resistor style spark Repeat the test between terminal #87 and pin #19 plugs. Equivalent alternate brand plugs can also be for coil #2.

  • Page 88: Battery Charging System

    Section 5B EFI Fuel System Fuel Components Fuel Pump Figure 5B-24. “24 Pin” (MSE 1.0) Plastic-Cased ECU Internal External Connector. Figure 5B-26. Fuel Pump Styles. General An electric fuel pump is used to transfer fuel in the EFI system. Depending on the application, the pump may be inside the fuel tank, or in the fuel line near the tank.

  • Page 89: Fuel Pressure Regulator

    Section 5B EFI Fuel System 1. Connect the black hose of Pressure Tester (part of Fuel Pressure Regulator EFI Service Kit, see Section 2), to the test valve in the fuel rail. Route the clear hose into a portable gasoline container or the equipment fuel tank. 2.
  • Page 90 Section 5B EFI Fuel System Pressure Regulating Pressure Spring Regulating Chamber Diaphragm Valve Seat Valve Fuel Chamber Inlet Port Outlet Port (to fuel rail) Return Port (to tank) Figure 5B-29. Fuel Pressure Regulator Details. Service Depending on the application, the regulator may be located in the fuel tank along with the fuel pump, or outside the tank just down line from the pump.

  • Page 91: Fuel Filter

    Fuel Line Service Kit, Part No. 25 111 37-S (containing 60" of high-pressure hose and 10 Oetiker clamps), or use only the type specified. Special Oetiker clamps (Kohler Part No. 24 237 05-S) are used on all fuel line Locking Clip Fuel...

  • Page 92: Throttle Body/Intake Manifold Assembly

    (1/4” ID). All high-pressure fuel line connections than normal, but gradually increase to the established must be secured with Oetiker Clamps (Kohler Part No. setting as operation continues. Do not attempt to 24 237 05-S), installed/crimped with the corresponding circumvent this warm up period, or readjust the idle pliers.

  • Page 93: Initial Governor Adjustment

    Section 5B EFI Fuel System If the governor/throttle components are all intact, but 1-3 mm (0.039-0.117 in.) you think there may be a problem with the Dampening Exposed Length Off End Spring adjustment, follow Procedure A to check the setting. If Of Adjustment Screw the governor lever was loosened or removed, go (Some Models)
  • Page 94 Section 5B EFI Fuel System a. On engines without a stop screw, pivot the B. Setting the Initial Adjustment throttle shaft and plate assembly into the “Full 1. Check the split where the clamping screw goes Throttle” position. Insert a 1.52 mm (0.060 in.) through the governor lever.

  • Page 95: Troubleshooting

    Section 5B EFI Fuel System 4. Verify that the governor has been set correctly. Engine starts hard or fails to start when hot With the linkage still retained in the “Full 1. Faulty spark plugs Throttle” position (Step 2), unsnap the bushing 2.

  • Page 96: Electrical System

    Section 5B EFI Fuel System Electrical System If a fault code indicates a problem with an electrical component, disconnect the ECU connector and test for The EFI system is a 12 VDC negative ground system, continuity between the component connector designed to operate down to a minimum of 7.0 volts.
  • Page 97 Section 5B EFI Fuel System “35 Pin” (MA 1.7) Metal-Cased ECU Systems Pin # Component Ignition Coil #1 Not used Engine Speed Sensor ECU Production Test Terminal Not Used Not Used Not Used TPS Initialization Terminal Engine Ground Sensor Not Used Throttle Position Sensor Not Used Oil Temperature Sensor...
  • Page 100 Section 5B EFI Fuel System “24 Pin” (MSE 1.0) Plastic-Cased ECU Systems Pin # Function Permanent Battery Voltage Switched Ignition Voltage Safety Switch Throttle Position Sensor (TPS) and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor (TPS) Input Speed Sensor Input Speed Sensor Ground Oxygen Sensor Input...
  • Page 101 Section 5B EFI Fuel System “32 Pin” (MSE 1.1) Plastic-Cased ECU Systems Pin # Function Permanent Battery Voltage Switched Battery Voltage TPS Set; “Auto-Learn” Initialization Terminal Throttle Position Sensor (TPS) and Temperature Sensor Ground Not Used Oil Temperature Sensor Input Not Used Throttle Position Sensor (TPS) Input Speed Sensor Input (+)

  • Page 103: Fuel System

    Section 5B EFI Fuel System Fault Codes Fuel System The ECU continuously monitors engine operation against preset performance limits. If the operation is WARNING: Fuel System Under Pressure! outside the limits, the ECU activates the MIL and The fuel system operates under high pressure. System stores a diagnostic code in its fault memory.
  • Page 104 Section 5B EFI Fuel System Example of Diagnostic Display 1. Diagnostic display initiated through ignition key sequencing. Long Pause Short Pauses Code 32 Long Pause Code 61 Long Pause Light remains on at end of transmission Figure 5B-43. After the problem has been corrected, the fault codes may be cleared as follows. 1.
  • Page 105 Section 5B EFI Fuel System 3 " " n 2 " " n 3 " " n c i l 3 " " n u l i i r c l a t c i t c i t : t i : t i v i t y t i...
  • Page 106 Section 5B EFI Fuel System Code: 4. ECU/Harness Related Source: Engine Speed Sensor a. ECU-to-harness connection problem. Explanation: ECU receiving inconsistent tooth count signals from speed sensor. 5. Ignition System Related Expected Engine a. Non-resistor spark plug(s) used. Response: Possible misfire as ECU attempts to resynchronize, during which time fuel Code: and spark calculations are not made.
  • Page 107 Section 5B EFI Fuel System 3. Engine Wiring Harness Related Code: “32 Pin” (MSE 1.1) Plastic-Cased ECU: Source: Fuel Mixture or Oxygen Sensor a. Pin circuits 4, 8, and/or 18 damaged (wiring, Explanation: “System too lean.” Oxygen sensor not connectors). sending expected voltage to ECU.
  • Page 108 Section 5B EFI Fuel System Code: Pin 20 for “32 Pin” (MSE 1.1) Plastic-Cased Source: Oxygen Sensor ECU. Explanation: No change in the sensor output signal. 3. TPS Sensor Related Expected Engine a. Throttle plate position incorrectly set or Response: “Open loop”...
  • Page 109 Section 5B EFI Fuel System 2. TPS Sensor Related 2. Engine Wiring Harness Related a. Throttle plate position incorrect during “32 Pin” (MSE 1.1) Plastic-Cased ECU: “Initialization” procedure. a. Pin circuits 4, 6 and/or (4A) damaged (wires, connectors) or routed near noisy signal (coils, b.
  • Page 110 Section 5B EFI Fuel System 5. Oxygen Sensor/Harness Related Possible Causes: a. Oxygen sensor bad. 1. Injector Related b. Wiring problem to oxygen sensor. a. Injector coil shorted or opened. c. Muffler leak (causing O sensor to falsely indicate a lean condition). 2.

  • Page 111: Troubleshooting Flow Chart

    Section 5B EFI Fuel System Code: "32 Pin" (MSE 1.1) Plastic- Code: Cased ECU only. Source: Source: Fuel pump relay circuit open, shorted Explanation: Denotes the end of fault codes. If to ground, or shorted to battery. signaled first, no other fault codes are Explanation: Fuel pump, ignition coils, and fuel present.
  • Page 112 Section 5B EFI Fuel System *Operate for an appropriate period of time based upon original fault codes. Figure 5B-44. 5B.43...

  • Page 113: Flow Chart Diagnostic Aids

    Section 5B EFI Fuel System Flow Chart Diagnostic Aids 11. Code 51 - Injector 1, "32 Pin" (MSE 1.1) Plastic- Cased ECU only. Diagnostic Aid #1 "SYSTEM POWER" (MIL does not 12. Code 52 - Injector 2, "32 Pin" (MSE 1.1) Plastic- illuminate when key is turned “on”) Cased ECU only.
  • Page 114 Section 5B EFI Fuel System Diagnostic Aid #4 “SPEED SENSOR” (MIL does not Diagnostic Aid #7 “IGNITION SYSTEM” (no spark) turn off during cranking). Indicates the ECU is not receiving a signal from the speed sensor. Possible causes: 1. Spark plug Possible causes: 2.
  • Page 115 Section 6 Lubrication System Section 6 Lubrication System General NOTE: Using other than service class SG, SH, SJ or higher oil, or extending oil change intervals This engine uses a full pressure lubrication system. longer than recommended can cause engine This system delivers oil under pressure to the damage.

  • Page 116: Section 6 Lubrication System

    Section 6 Lubrication System NOTE: To prevent extensive engine wear or damage, Checking Oil Level always maintain the proper oil level in the The importance of checking and maintaining the crankcase. Never operate the engine with the proper oil level in the crankcase cannot be oil level below the ‘‘L”...
  • Page 117 Replace the oil filter at least every other oil change filter an additional 3/4-1 turn. (every 200 hours of operation). Always use a genuine Kohler oil filter. Change the filter as follows. See 8. Remove the oil fill cap and fill the engine with the Figure 6-6.
  • Page 118 Section 6 Lubrication System Service Oil Cooler Oil Sentry ™ Some engines are equipped with an oil cooler. One style of oil cooler mounts on the engine crankcase and General has the oil filter on it. The other style of oil cooler is Some engines are equipped with an optional Oil ™...
  • Page 119 Section 6 Lubrication System 2. Gradually increase the pressure to the switch. As To install the switch, follow these steps: 1. Apply pipe sealant with Teflon ® (Loctite ® the pressure increases through the range of 3.0/5.0 psi the tester should indicate a change to 59241 or equivalent) to the threads of the switch.
  • Page 120 Section 7 Retractable Starter WARNING: Spring Under Tension! Retractable starters contain a powerful, recoil spring that is under tension. Always wear safety goggles when servicing retractable starters and carefully follow instructions in this section for relieving spring tension. To Remove Starter Starter Housing 1.

  • Page 121: Section 7 Retractable Starter

    Section 7 Retractable Starter Keep Pulley Rope Slipknot Handle from Rotating Guide Bushing Rope Hole Knot in Pulley Rope Retainer Figure 7-3. Installing Rope. Figure 7-2. Removing Starter Handle. 10. Tie a slipknot approximately 12 in. from the free 3. Remove the rope retainer from inside the starter end of rope.
  • Page 122 Section 7 Retractable Starter Disassembly Brake Spring and WARNING: Spring Under Tension! Brake Washer 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.
  • Page 123 See Figure 7-9. damage. 2. Replace all worn or damaged components. Use Pawl only genuine Kohler replacement parts as specified in the Parts Manual. All components shown in Figure 7-1 are available as service parts. Do not use nonstandard parts.
  • Page 124 Section 7 Retractable Starter 4. Place the brake washer in the recess in starter 7. Tension the spring and install the rope and pulley; over the center shaft. handle as instructed in steps 6 through 12 under “Rope Replacement” on page 7.2. 5.
  • Page 125 The engine is equipped with the following spark plugs: Type: The standard spark plug is a Champion ® RC12YC (Kohler Part No. 12 132 02-S). RFI compliant engines use a Champion ® XC12YC (Kohler 25 132 14-S) spark plug. A high- ®...

  • Page 126: Section 8 Electrical System And Components

    Section 8 Electrical System and Components Normal: A plug taken from an engine operating under Wet Fouled: A wet plug is caused by excess fuel or oil normal conditions will have light tan or gray colored in the combustion chamber. Excess fuel could be deposits.
  • Page 127 Section 8 Electrical System and Components Battery 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 General battery to self-discharge. Self-discharge occurs A 12-volt battery with 400 cold cranking amps is rapidly when moisture is present.
  • Page 128 Section 8 Electrical System and Components Electronic CD Ignition Systems Carburetor Solenoid Starter and Ignition Spark Pressure Carburetor Module Advance Safety Green Solenoid Input Module Input White (Optional) Oil Pressure B+ and Spark Ignition Safety Input Carburetor Plugs Modules Solenoid Input Violet Rectifier-...
  • Page 129 Section 8 Electrical System and Components Kill Switch or Ignition ‘‘Off’’ Position of Modules Key Switch Spark Plug Magnet (0.28/0.33 mm) 0.011/0.013 in. Air Gap Flywheel Figure 8-4. Capacitive Discharge (Fixed Timing) Ignition System. The timing of the spark is controlled by the location of the flywheel magnet group as referenced to engine top dead center.
  • Page 130 Section 8 Electrical System and Components 12 Volt Battery Green Key Switch or ‘‘Off’’ Spark Position of Key Switch Advance White Module Spark Spark Plug Plug 0.28/0.33 mm Ignition (0.011/0.013 in.) Module Air Gap Flywheel Magnet Figure 8-6. Capacitive Discharge Ignition System with Spark Advance. The timing of the spark is controlled by the location of the flywheel magnet group as referenced to the engine top dead center and the delay created by the spark advance module.
  • Page 131 2. Test for spark on both cylinders with Kohler ignition tester (see Section 2). Disconnect one spark CAUTION: High-Energy Electric Spark! plug lead and connect it to the post terminal of the The CD ignition systems produce a high-energy electric tester.
  • Page 132 Section 8 Electrical System and Components c. If neither side is firing, recheck position of **NOTE: If the engine starts or runs during any of the ignition switch and check for shorted kill lead. testing, you may need to ground the kill lead to shut it down.
  • Page 133 All modules with vendor part numbers MA-2, MA-2A, or MA-2B (Kohler Part No. 24 584 03) should be replaced with 24 584 11 or 24 584 15-S. For small modules with vendor numbers MA-2C or MA-2D (Kohler Part No.
  • Page 134 Section 8 Electrical System and Components Ignition Module Resistance Table 4) Position a 0.30 mm (0.012 in.) feeler gauge between the magnet and all three legs of the 24 584 03 or 24 584 15-S or module. The ignition module air gap is 24 584 11 24 584 36-S critical to proper system performance.
  • Page 135 Section 8 Electrical System and Components a. If correct voltage is not measured, connect To Test – Using 25 761 21-S Tester black voltmeter lead directly to the negative (-) post of the battery and test voltage again ASAM (only) Test Procedure in both key positions.
  • Page 136 Section 8 Electrical System and Components Figure 8-12. Figure 8-13. 2. Check the SAM part number stamped on the side **The tester is powered by a 9-volt battery. Most of the housing. Verify that you have an analog SAMs are designed to operate down to a minimum SAM (ASAM) Part No.
  • Page 137 Section 8 Electrical System and Components • Brown tester lead with black band or ASAM Module terminal to the short brown module lead. Test Connections NOTE: Some modules contain two black ground leads, with one containing a white stripe. Do not connect to the black/white lead with the bullet connector or a “Fail”...
  • Page 138 Section 8 Electrical System and Components **The tester is powered by a 9-volt battery. Most SAMs are designed to operate down to a minimum of 7.25 volts. If the tester battery drops below that level, incorrect test readings will result. The tester battery should be checked periodically by connecting a DC voltmeter between the red and green lead wires, with the tester connected to a...
  • Page 139 Section 8 Electrical System and Components • Make sure the battery polarity is correct. A Battery Charging System negative (-) ground system is used. General • Disconnect the rectifier-regulator plug and/or the Most engines are equipped with a 15 or 20 amp wiring harness plug before doing any electric regulated charging system.
  • Page 140 Section 8 Electrical System and Components Figure 8-18. Wiring Diagram - 15/20/25 Amp Regulated Battery Charging System with SMART-SPARK ™ Figure 8-19. 15 Amp Stator and Rectifier-Regulator. Figure 8-20. 20 Amp Stator and Rectifier-Regulator. 8.16...
  • Page 141 Section 8 Electrical System and Components 1st Style 25 Amp Stator 2nd Style Figure 8-21. 25 Amp Stator and Rectifier-Regulators. 3 Amp Unregulated Charging System Ground-To-Kill Lead (White) Light Ignition (Blue) Modules Spark Spark (Red) Plug Plug Switch (Black) Optional Diode 3 Amp/70 Watt Fuse...
  • Page 142 Section 8 Electrical System and Components 3 Amp Charging Stator Lighting Lead (Yellow) Diode Charging Lead (Black) Lighting Stator Figure 8-23. 3 Amp/70 Watt Stator. Stator To Test – The stator is mounted on the crankcase behind the NOTE: Disconnect all electrical connections attached flywheel.
  • Page 143 Section 8 Electrical System and Components 20/25 Amp Rectifier-Regulators 3. Plug the tester into the proper AC outlet/power for tester being used. Turn on the power switch. 1. Connect the single lead adapter in between the See Figure 8-26. The ‘‘POWER’’ light should be B+ (center) terminal of rectifier-regulator being illuminated and one of the four status lights may tested and the squared single end of the tandem...
  • Page 144 Section 8 Electrical System and Components 6. Press the ‘‘TEST’’ button until a ‘‘click’’ is heard and then release. See Figure 8-27. Momentarily one of the four lights will illuminate indicating the partial condition of the part. a. If the ‘‘OK’’ (green) light comes on, disconnect the tester black lead attached to one AC terminal and reconnect it to the other AC terminal.
  • Page 145 Section 8 Electrical System and Components 4. Press the ‘‘TEST’’ button until a “click” is heard and then release. See Figure 8-27. Momentarily either the ‘‘HIGH’’, ‘‘LOW’’, or ‘‘SHORT’’ light will flash. a. If the “HIGH” light flashes on/off, the part is good and may be used.
  • Page 146 Section 8 Electrical System and Components Troubleshooting Guide 15/20/25 Amp Battery Charging Systems When problems occur in keeping the battery charged or the battery charges at too high a rate, the problem can usually be found somewhere in the charging system or with the battery. NOTE: Always zero ohmmeter on each scale before testing to ensure accurate readings.
  • Page 147 Section 8 Electrical System and Components Troubleshooting Guide 3 Amp Battery Charging System with 70 Watt Lighting Stator NOTE: Zero ohmmeters on each scale to ensure accurate readings. Voltage tests should be made with engine running at 3000 RPM - no load. Battery must be good and fully charged. Conclusion Problem Test...
  • Page 148 Section 8 Electrical System and Components Electric Starting Motors NOTE: If the starter does not crank the engine, shut off the starter immediately. Do not make Some engines in this series use inertia drive starting further attempts to start the engine until the motors while most use solenoid shift starters.
  • Page 149 4. Clean the splines on drive shaft thoroughly with solvent. Dry the splines thoroughly. 5. Apply a small amount of Kohler electric starter drive lubricant, (see Section 2) to the splines. The use of other lubricants may cause the drive pinion to stick or bind.
  • Page 150 7. The splines should have a light film of lubricant. ring in the inner groove (see Figure 8-36). Slide Relubricate as necessary with Kohler bendix the collar over the inner halves to hold them in starter lubricant (see Section 2). Reinstall or position.
  • Page 151 Section 8 Electrical System and Components Retaining Ring Installation 2. Locate the small raised line on the edge of the 1. Position the retaining ring in the groove in one of drive end cap. On starters with Style ‘‘A’’ the inner halves. Assemble the other half over the commutator end caps, it will be aligned with a top and slide on the outer collar.
  • Page 152 Section 8 Electrical System and Components NOTE: Use a brush holder tool to keep the 2. Insert the armature into the starter frame. Make brushes in the pockets. A brush holder sure the magnets are closer to the drive shaft end tool can easily be made from thin sheet of armature.
  • Page 153 7. Lubricate the drive shaft with Kohler bendix with the ring gear into the retracted position. starter drive lubricant (see Section 2). Install the drive components following the instructions for servicing the starter drive.
  • Page 154 Brush Replacement The brushes in the starter are part of the starter frame. Brush kit, Kohler Part No. 52 221 01-S, contains four replacement brushes and springs. If replacement is necessary, all four brushes should be replaced.
  • Page 155 Section 8 Electrical System and Components Phillips Head Screws Torx Head Screws Figure 8-45. Removing Solenoid Screws. Figure 8-46. Solenoid Removed from Starter. 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 Torx head screws, the plunger is part of the solenoid, unhook the plunger pin from the drive lever.
  • Page 156 Section 8 Electrical System and Components 7. Remove the drive lever pivot bushing and backing plate from the end cap. See Figure 8-51. Figure 8-48. Removing Thru Bolts. 5. Remove the commutator end plate assembly, Figure 8-51. containing the brush holder, brushes, springs, and locking caps.
  • Page 157 Section 8 Electrical System and Components Figure 8-53. Retaining Ring Detail. Figure 8-54. Removing Retaining Ring. 11. Remove the retainer from the armature shaft. 12. Remove the drive pinion assembly from the Save the stop collar. armature. NOTE: Do not reuse the old retainer. 13.
  • Page 158 Section 8 Electrical System and Components Inspection Commutator O.D. Drive Pinion Check and inspect the following areas: a. The pinion teeth for abnormal wear or damage. b. The surface between the pinion and the clutch mechanism for nicks, or irregularities which could cause seal damage.
  • Page 159 The brushes and springs are serviced as a set (4). Use Clean the drive lever and armature shaft. Apply Brush and Spring Kit, Kohler Part No. 25 221 01-S, if Kohler electric starter drive lubricant (see Section 2) replacement is necessary.
  • Page 160 Section 8 Electrical System and Components 7. Install the backup washer, followed by the rubber grommet, into the matching recess of the drive end cap. The molded recesses in the grommet should be “out”, matching and aligned with those in the end cap. See Figure 8-64. Figure 8-62.
  • Page 161 Section 8 Electrical System and Components Figure 8-66. Installing Thrust Washer. Figure 8-68. Removing Retaining Clips. 10. Starter reassembly when replacing the Brushes/ b. Position each of the brushes back in their slots Brush Holder Assembly: so they are flush with the I.D. of the brush holder assembly.
  • Page 162 Section 8 Electrical System and Components Figure 8-70. Installing Brush Holder Assembly Figure 8-72. Torquing Brush Holder Screws. using Tool with Extension. 13. Hook the plunger behind the upper end of the 11. Install the end cap onto the armature and frame, drive lever, and install the spring into the aligning the thin raised rib in the end cap with solenoid.
  • Page 163 Section 8 Electrical System and Components Solenoid Test Procedure 12 volt Test Leads Momentary Solenoid Shift Style Starters Connection Only Disconnect all leads from the solenoid including the positive brush lead attached to the lower stud VOM Leads terminal. Remove the mounting hardware and separate the solenoid from the starter for testing.
  • Page 164 Section 8 Electrical System and Components Test 4. Solenoid Hold-In Coil/Contact Continuity Test. Use an ohmmeter set to the audible or Rx2K scale, and connect the two ohmmeter leads to the two large post terminals. Perform the preceding test (3) and check for VOM Meter continuity.
  • Page 165 Section 9 Disassembly 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 cable from battery. General 20.

  • Page 166: Section 9 Disassembly

    Section 9 Disassembly 3. Remove and discard the oil filter. See Figure 9-5. Figure 9-2. Removing Dipstick from Tube. Figure 9-5. Removing Oil Filter. Figure 9-3. Removing Oil Fill Cap from Cover. Figure 9-4. Removing Oil Drain Plug. Figure 9-6. Removing Oil Filter Adapter Nipple. 2.
  • Page 167 Section 9 Disassembly 4. Remove the hex flange screws securing the bracket and base. See Figure 9-8. Two additional rear screws must be removed if the engine contains a rear air cleaner support bracket. See Figure 9-9. Figure 9-8. Removing Air Cleaner Base Retainer. Figure 9-7.
  • Page 168 Section 9 Disassembly Mounting Screws Figure 9-11. Removing Tube from Breather Cover. Figure 9-13. Air Cleaner Bracket Mounting Screws (Two-Barrel Model Pictured). 6. Remove the rubber breather tube from the breather cover. See Figure 9-11. 4. Remove the heavy-duty air cleaner as an assembly from the engine.
  • Page 169 Section 9 Disassembly 3. Remove the two hex flange screws securing the fuel pump to the bracket or to the blower housing. See Figure 9-18. The fuel pump body may be metal or plastic. Figure 9-15. Disconnecting Fuel Inlet Line at Carburetor.
  • Page 170 Section 9 Disassembly Figure 9-20. Mechanical Fuel Pump. Figure 9-22. Rear Air Cleaner Bracket (Some Models). Remove Control Panel (If So Equipped) 2. Mark the spring hole locations and disconnect 1. Disconnect the Oil Sentry™ Indicator Light the spring from the governor lever. See Figure wires.
  • Page 171 Section 9 Disassembly Remove External Governor Controls 2. One-Barrel Carburetor Models Only: Remove the two carburetor mounting screws. See Figure 1. Loosen the hex flange nut and remove the 9-27. governor lever from the cross shaft. See Figure 9-25. Leave lever attached to the throttle linkage Two-Barrel Carburetor Models Only: If required and lay assembly on the top of the crankcase.
  • Page 172 Section 9 Disassembly 5. If necessary, the carburetor, throttle linkage and Remove Outer Baffles and Blower governor lever can be separated. Reattach the Housing bushings to the linkage following separation to 1. Disconnect the plug from the rectifier-regulator avoid losing them. on the blower housing.
  • Page 173 Section 9 Disassembly Figure 9-35. Removing Outer Baffles. 5. Remove the outer baffles on both sides. See Figure 9-35. 6. On engines equipped with a metal grass screen, remove the screen before removing the blower housing. See Figure 9-36. Plastic grass screens can be removed after the blower housing is removed.
  • Page 174 Section 9 Disassembly Debris Shield Mounting Screws Figure 9-39. Removing Fasteners Holding Baffle Figure 9-37. Debris Shield Details (Two-Barrel and Breather Cover. Carburetor Model Shown). 2. Remove both inner baffles. See Figure 9-40. 9. Remove the remaining hex flange screws and detach the blower housing.
  • Page 175 Section 9 Disassembly 7. Remove the hex flange screw, breather reed retainer and breather reed. See Figure 9-44. Figure 9-41. Breaking Breather Cover Seal. 5. Remove the breather cover and gasket (if used). Figure 9-44. Removing Breather Reed. See Figure 9-42. Remove Valve Covers Three valve cover designs have been used.
  • Page 176 Section 9 Disassembly Remove Ignition Modules 3. Leave the wiring harness attached to the manifold. 1. Disconnect the lead(s)* from each ignition module. See Figure 9-46. *Modules for non- Aluminum SMART-SPARK ignition systems have only one ™ Intake kill lead. Manifold Plastic Intake Manifold...
  • Page 177 Section 9 Disassembly Hex Flange Screw Figure 9-49. Bolt Wiring Harness Detail. Hex Flange Nut and Washer Remove Spark Plugs 1. Remove the spark plug from each cylinder head. Figure 9-51. Removing Cylinder Head Fasteners. 2. Mark the position of the push rods as either intake or exhaust and cylinder 1 or 2.
  • Page 178 Section 9 Disassembly Hex Flange Screw Style Mounting Figure 9-53. Removing Hydraulic Lifter. Stud and Hex Flange Nut Style Mounting Figure 9-52. Removing Cylinder Head Assembly. Figure 9-54. Mark Position of Hydraulic Lifters. 4. Remove the lifters from the lifter bores. Use a Hydraulic Lifter Tool.
  • Page 179 Section 9 Disassembly Disassemble Cylinder Heads 3. Once the valve spring is compressed, remove the following items. See Figures 9-58 and 9-59. 1. Remove the two hex flange screws, rocker arm pivots and rocker arms from the cylinder head. • Valve spring keepers See Figure 9-56.
  • Page 180 Section 9 Disassembly Figure 9-60. Removing Plastic Type Grass Screen. Figure 9-62. Removing Flywheel Fastener Using Strap Wrench. 2. Remove the four hex flange screws and fan. See Figure 9-61. 2. Remove the hex flange screw and washer. 3. Use a puller to remove the flywheel from the crankshaft.
  • Page 181 Section 9 Disassembly 2. Locate the three splitting tabs that are cast into the perimeter of the closure plate. Insert the drive end of a 1/2" breaker bar between the top splitting tab and the crankcase. Hold the handle horizontal and pull toward you to break the RTV seal.
  • Page 182 Section 9 Disassembly Remove Camshaft 1. Remove the camshaft and shim. See Figure 9-69. Camshaft Shim Figure 9-71. Mark End Cap with Cylinder Number Before Removal. Figure 9-69. Removing Camshaft (Note Shim). NOTE: The cylinders are numbered on the crankcase. Use the numbers to mark each Remove Connecting Rods with Pistons end cap, connecting rod and piston for reassembly.
  • Page 183 Section 9 Disassembly Remove Crankshaft 1. Carefully pull the crankshaft from the crankcase. See Figure 9-73. Note thrust washers and shims if used. Figure 9-75. Removing Governor Cross Shaft Retainer (8 mm Shaft Design). 2. Pull the cross shaft with small washer out through the inside of the crankcase.
  • Page 184 Section 10 Inspection and Reconditioning Section 10 Inspection and Reconditioning This section covers the operation, inspection, and Automatic Compression Release (ACR) repair/reconditioning of major internal engine Some engines are equipped with the optional components. The following components are not Automatic Compression Release (ACR) mechanism. covered in this section.

  • Page 185: Section 10 Inspection And Reconditioning

    Procedure to Install New Plug: 1. Use a single cylinder camshaft pin, Kohler Part Inspect the crankpin for score marks or metallic No. 47 380 09-S as a driver and tap the plug into pickup.
  • Page 186 Section 10 Inspection and Reconditioning NOTE: Kohler pistons are custom-machined to Check the cylinder bore wall for scoring. In severe exacting tolerances. When oversizing a cases, unburned fuel can cause scuffing and scoring of cylinder, it should be machined exactly the cylinder wall.
  • Page 187 Before installing the piston into the cylinder bore, it is necessary that the clearance be accurately checked. Inspect the ring gear for cracks or damage. Kohler This step is often overlooked, and if the clearances are does not provide the ring gear as a serviceable part.
  • Page 188 Section 10 Inspection and Reconditioning EXHAUST INTAKE VALVE VALVE EXHAUST INSERT INTAKE INSERT Dimension Intake Exhaust Seat Angle 89° 89° 36.987/37.013 mm (1.4562/1.4572 in.) Insert O.D. 32.987/33.013 mm (1.2987/1.2997 in.) 4 mm (0.1575 in.) Guide Depth 6.5 mm (0.2559 in.) 7.038/7.058 mm (0.2771/0.2779 in.) Guide I.D.
  • Page 189 Section 10 Inspection and Reconditioning Normal: Even after long hours of operation a valve Leakage: A poor grind on face or seat of valve will can be reconditioned and reused if the face and allow leakage resulting in a burned valve on one side margin are in good shape.
  • Page 190 Section 10 Inspection and Reconditioning Stem Corrosion: Moisture in fuel or from Excessive Combustion Temperatures: The white condensation are the most common causes of valve deposits seen here indicate very high combustion stem corrosion. Condensation occurs from improper temperatures, usually due to a lean fuel mixture. preservation during storage and when engine is repeatedly stopped before it has a chance to reach normal operating temperatures.
  • Page 191 Section 10 Inspection and Reconditioning Valve Guides If a valve guide is worn beyond specifications, it will not guide the valve in a straight line. This may result in burnt valve faces or seats, loss of compression, and Valve Seat Cutter excessive oil consumption.
  • Page 192 Section 10 Inspection and Reconditioning Ring failure is usually indicated by excessive oil Detonation damage occurs when a portion of the fuel consumption and blue exhaust smoke. When rings charge ignites spontaneously from heat and pressure fail, oil is allowed to enter the combustion chamber shortly after ignition.
  • Page 193 Section 10 Inspection and Reconditioning Replacement pistons are available in STD bore size, and in 0.25 mm (0.010 in.), and 0.50 mm (0.020 in.) oversize. Replacement pistons include new piston ring sets and new piston pins. Replacement ring sets are also available separately for STD, 0.25 mm (0.010 in.), and 0.50 mm (0.020 in.) oversize pistons.
  • Page 194 Check the base surface of the hydraulic lifters for wear Piston or damage. If the lifters need to be replaced, apply a liberal coating of Kohler lubricant (see Section 2) to the base of each new lifter before it is installed. Compression Ring “Bleeding”...
  • Page 195 Section 10 Inspection and Reconditioning Reassembly Disassembly 1. Install the locking tab thrust washer on the The governor gear must be replaced once it is governor gear shaft with the tab down. removed from the closure plate. 2. Position the regulating pin within the governor NOTE: The governor gear is held onto the shaft by gear/flyweight assembly and slide both onto the small molded tabs in the gear.
  • Page 196 Section 10 Inspection and Reconditioning 3. Install the rotor. 4. Install the oil pump body to the closure plate and secure with the two hex flange screws. Torque the hex flange screws as follows: a. Install fastener into location No. 1 and lightly tighten to position pump.
  • Page 197 Section 10 Inspection and Reconditioning Section 10 Inspection and Reconditioning This section covers the operation, inspection, and Automatic Compression Release (ACR) repair/reconditioning of major internal engine Some engines are equipped with the optional components. The following components are not Automatic Compression Release (ACR) mechanism. covered in this section.
  • Page 198 Section 10 Inspection and Reconditioning Governor Cross Shaft Oil Seal If the governor cross shaft seal is damaged and/or leaks, replace it using the following procedure. Remove the oil seal from the crankcase and replace it with a new one. Install the new seal to the depth shown in Figure 10-18 using a seal installer.
  • Page 199 Section 11 Reassembly Section 11 Reassembly 14. Install intake manifold. General 15. Install breather cover and inner baffles. NOTE: Make sure the engine is assembled using all 16. Install blower housing and outer baffles. specified torque values, tightening sequences 17. Install electric starter motor. and clearances.

  • Page 200: Section 11 Reassembly

    Section 11 Reassembly Figure 11-4. Installing Governor Cross Shaft Hitch Figure 11-2. Installing Oil Seal. Pin (6 mm Shaft). Install Governor Cross Shaft 1. Lubricate the governor cross shaft bearing surfaces in the crankcase with engine oil. 2. Slide the small lower washer onto the governor cross shaft and install the cross shaft from the inside of the crankcase.
  • Page 201 Section 11 Reassembly 2. Lubricate the cylinder bore, piston, and piston rings with engine oil. Compress the rings of the #1 piston using a piston ring compressor. 3. Lubricate the crankshaft journals and connecting rod bearing surfaces with engine oil. 4.
  • Page 202 Section 11 Reassembly Torque these to 22.7 N·m (200 in. lb.) 8 mm Straight Shank Torque these to 14.7 N·m (130 in. lb.) 8 mm Step-Down Torque these to 11.3 N·m (100 in. lb.) Figure 11-12. Apply Camshaft Lubricant to Cam 6 mm Straight Shank Lobes.
  • Page 203 Section 11 Reassembly 5. Reinstall the end play checking tool and recheck the end play. Oil Pump Assembly The oil pump is mounted inside the closure plate. If service was required, and the oil pump was removed, refer to the assembly procedures under “Oil Pump Assembly”...
  • Page 204 Section 11 Reassembly Remove the closure plate. If end play requires adjustment, remove the original spacer and install the Thrust Shim appropriate size shim spacer in its place. Then follow the procedure under “Install Closure Plate Assembly.” Thrust Install Closure Plate Oil Seal Washer 1.
  • Page 205 Section 11 Reassembly 3. Apply a 1.5 mm (1/16 in.) bead of sealant to the 6. Install the ten hex flange screws securing the sealing surface of the closure plate. See Figure closure plate to the crankcase. Torque fasteners in the sequence shown in Figure 11-21 to 24.4 N·m 11-19 for sealant pattern.
  • Page 206 Section 11 Reassembly Install Flywheel WARNING: Damaging Crankshaft and Flywheel Can Cause Personal Injury! Using improper procedures to install the flywheel can crack or damage the crankshaft and/or flywheel. This not only causes extensive engine damage, but can also cause personal injury, since broken fragments could be thrown from the engine.
  • Page 207 Section 11 Reassembly Install Flywheel Fan 1. Install the fan onto the flywheel using the four hex flange screws. NOTE: Position the ears located at rear perimeter of the fan in the recesses of the flywheel. See Figure 11-30. Figure 11-28. Carefully Align Keyway to Key. NOTE: Make sure the flywheel key is installed properly in the keyway.
  • Page 208 Section 11 Reassembly Install Supports for the Metal Grass Screen 1. If a metal grass screen is used, with threaded individual supports, install a spacer washer on the external threads. Apply blue Loctite ® No. 242 (removable) onto the threads. Install the four supports as shown in Figure 11-32.
  • Page 209 Section 11 Reassembly Valve Keepers Retainer Figure 11-36. Match Numbers on Cylinder Barrel and Spring Head. Figure 11-38. Valve Components. Intake Valve Seal Figure 11-37. Intake Valve Seal Location. Figure 11-39. Installing Valves with Valve Spring Valve Stem Seals Compressor. These engines use valve stem seals on the intake valves and occasionally on the exhaust valves.
  • Page 210 Section 11 Reassembly Heads secured with hex flange screws: 2. Install a new cylinder head gasket, (with printing up). Figure 11-42. Cylinder Head Fastener Torque Sequence. Heads secured with mounting studs, nuts, and Figure 11-40. Always Use New Head Gaskets. washers: 1.
  • Page 211 Section 11 Reassembly NOTE: Push rods should always be installed in the same position as before disassembly. 1. Note the mark or tag identifying the push rod as either intake or exhaust and cylinder #1 or #2. Dip the ends of the push rods in engine oil and install, making sure that each push rod ball seats in its hydraulic lifter socket.
  • Page 212 Section 11 Reassembly Install Ignition Modules 5. Repeat the above steps for the remaining cylinder. Do not interchange parts from the 1. Rotate the flywheel to position the magnet away cylinder heads. from the ignition module bosses. Figure 11-47. Using Spanner Wrench to Lift Rocker Figure 11-49.
  • Page 213 Section 11 Reassembly Sealant Figure 11-50. Setting Ignition Module Air Gap. Figure 11-52. Sealant Applied to Terminals. 6. Torque the screws to 4.0-6.2 N·m (35-55 in. lb.). NOTE: If the wires were disconnected from the ignition modules on engines with SMART- 7.
  • Page 214 Section 11 Reassembly 3. Install the breather reed and breather reed 3. Connect the kill lead to the tab terminal on retainer onto the crankcase and secure with the standard ignition modules. See Figure 11-54. hex flange screw. Hold the assembly in line when tightening.
  • Page 215 Section 11 Reassembly Install Blower Housing and Outer Baffles NOTE: Do not completely tighten screws until all items are installed to allow shifting for hole alignment. 1. Connect the plug to the key switch in the blower housing (if so equipped). 2.
  • Page 216 Section 11 Reassembly 3. Position the outer baffles and loosely start the mounting screws. The two M6 screws go into the back of the cylinders. The short M5 screws go into the lower holes closest to the blower housing. The short screw on the oil filter side is also used to mount the wire harness clip.
  • Page 217 Section 11 Reassembly 7. Torque the four breather cover screws to 7.3 N·m (65 in. lb.) in the sequence shown in Figure 11-68. Figure 11-65. Tighten Short Screws to Torque Specified. Figure 11-68. Breather Cover Fastener Torque Sequence. Reconnect Rectifier-Regulator 1.
  • Page 218 Section 11 Reassembly Cylinder Baffle Mounting Location Figure 11-70. Installing B+ Lead into Plug. Blower Housing Mounting Location Grounding Figure 11-72. Reinstalling SAM Module. Bracket Figure 11-71. Grounding Bracket and Attached Install Electric Starter Motor Connector. 1. Install the starter motor using the two hex flange screws.
  • Page 219 Section 11 Reassembly 3. On models with a solenoid shift starter, connect the leads to the solenoid. See Figure 11-74. Metal-Cased Pulse Fuel Pump Figure 11-74. Connecting Leads to Starting Motor. NOTE: If the engine uses a side mount muffler on the starter side, be sure to tie the wires close to the starter to avoid contact with hot exhaust parts.
  • Page 220 Section 11 Reassembly Figure 11-78. Installing Studs and Carburetor (Two- Figure 11-76. Installing Carburetor Assembly. Barrel Carburetor). 4. Connect the ground lead and fuel solenoid lead as equipped. See Figure 11-79. Figure 11-77. Ground Lead on Carburetor Mounting Screw (One-Barrel Carburetor). 3.
  • Page 221 Section 11 Reassembly 2. Make sure the throttle linkage is connected to the governor lever and the throttle lever on the carburetor. 3. Move the governor lever toward the carburetor as far as it will go (wide-open throttle) and hold in position.
  • Page 222 Section 11 Reassembly 3. Connect the governor spring from the main control bracket to the appropriate hole in the governor lever as indicated in the following Colored on End Only charts. Note that hole positions are counted from the pivot point of the governor lever. See Figures 11-85 and 11-86, and the appropriate chart.
  • Page 223 Section 11 Reassembly 8 mm Governor Lever and Hole Position/RPM Charts Governor Lever CH18 Engines Intended Non-Accelerator Accelerator Governor Shaft Maximum RPM Pump Carburetor Pump Carburetor Configuration High Idle Spring Color Hole No. Spring Color Hole No. 3744 3600 Orange Needle Bearing 3120 3000...
  • Page 224 Section 11 Reassembly Item Description Bracket, speed control Clamp, cable (some applications) Kill Switch (some applications) Lever, choke (top position) Lever, throttle control (middle) Linkage, choke control Lever, throttle actuator (bottom) Screw, M5x0.8x20 Washer, wave Washer, flat (3) Spring, choke return Nut, M5x0.8 lock Figure 11-87.
  • Page 225 Section 11 Reassembly Install Valve Covers Gasket/RTV style cover ....3.4 N·m (30 in. lb.) Black O-Ring style cover Three valve cover designs have been used. The with shoulder screws ..5.6 N·m (50 in. lb.) earliest type used a gasket and RTV sealant between with screws and spacers ..
  • Page 226 Section 11 Reassembly 3. Secure the air cleaner base and bracket using the hex flange screws. Position the bracket with the hole toward the breather hose. Be careful not to drop screws into the carburetor. If a rear air cleaner bracket is used, install the two M5 screws through the rear of the base.
  • Page 227 Section 11 Reassembly Carburetor Inlet Fuel Line Figure 11-96. Breather Hose and Fuel Line Details. Figure 11-98. Assembled Heavy Duty Air Cleaner (Two-Barrel Carburetor). 2. Align the air cleaner mounting bracket with the valve cover mounting holes and start the screws. Install Muffler On two-barrel carburetor models start the two 1.
  • Page 228 Section 11 Reassembly Mounting Locations Figure 11-102. Hand Tightening Oil Filter. Figure 11-100. Mounting Oil Cooler (Blower Housing Mounted Cooler). 4. Install the oil drain plugs. See Figure 11-103. Torque the plugs to 13.6 N·m (10 ft. lb.). Install Oil Filter and Fill Crankcase with Oil 1.
  • Page 229 Section 11 Reassembly Prepare the Engine for Operation The engine is now completely reassembled. Before starting or operating the engine, be sure to do the following. 1. Make sure all hardware is tightened securely. 2. Make sure the oil drain plugs, oil sentry pressure switch, and a new oil filter are installed.
  • Page 230 Section 12 Clutch Section 12 Clutch Clutch General Some engines are equipped with a “wet” disc type clutch. See Figure 12-1 for exploded view of clutch. Nameplate Shifting Lever Gasket Clutch Yoke Housing Seal Shaft (Yoke) Roll Pin Adjusting Oil Seal Ring Power Driven...

  • Page 231: Section 12 Clutch

    Section 12 Clutch Service 2. After adjustment is made, engage clutch and On this type, an oil “splash” type lubrication system is check to make sure rollers go over center to lock used. The proper oil level must be maintained to the unit in engaged position and prevent provide efficient lubrication.
  • Page 232 FORM NO.: TP-2428-C ISSUED: 4/92 REVISED: 3/06 LITHO IN U.S.A. FOR SALES AND SERVICE INFORMATION IN U.S. AND CANADA, CALL 1-800-544-2444 ENGINE DIVISION, KOHLER CO., KOHLER, WISCONSIN 53044...

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