SH255, SH265, SH270 Service Manual IMPORTANT: Read all safety precautions and instructions carefully before operating equipment. Refer to operating instruction of equipment that this engine powers. Ensure engine is stopped and level before performing any maintenance or service.
Safety SAFETY PRECAUTIONS WARNING: A hazard that could result in death, serious injury, or substantial property damage. CAUTION: A hazard that could result in minor personal injury or property damage. NOTE: is used to notify people of important installation, operation, or maintenance information. WARNING Explosive Fuel can cause fires and severe burns. Do not fill fuel tank while engine is hot or running. Gasoline is extremely flammable and its vapors can explode if ignited.
Maintenance MAINTENANCE INSTRUCTIONS WARNING Accidental Starts can cause severe injury or death. Disconnect and ground spark plug lead(s) before servicing. Before working on engine or equipment, disable engine as follows: 1) Disconnect spark plug lead(s). 2) Disconnect negative (–) battery cable from battery.
Maintenance OIL RECOMMENDATIONS All-season KOHLER® PRO 10W-50 Synthetic Oil is the ideal oil for KOHLER engines. It is specifically formulated to extend the oil change interval to 300 Hours. Contact your Kohler authorized dealer for availability. 300-Hour oil change intervals are exclusive to and only authorized on KOHLER engines that utilize the KOHLER PRO 10W-50 Synthetic Oil. Alternative engine oils may be used with KOHLER engines but require 100-Hour oil change intervals for proper maintenance.
Specifications Engine Dimensions Dimensions in millimeters. Inch equivalents shown in [ ]. 369.40 [14.543] 318.66 [12.545] STRAIGHT PTO 181.60 [7.150] 113.44 [4.466] SPARK PLUG 273.97 [10.786] OIL FILL DRAIN PLUG 2X Ø 10.00 [0.394] 37.98 [1.495] 37.50 [1.476] 78.00 [3.071] 2X 10.00 X 15.50 SLOT [0.394 X 0.610] 12.50 [0.492] GAS CAP REMOVAL 110.00 [4.331] AIR CLEANER COVER REMOVAL 88.00 [3.465] 339.90 [13.382] 342.20 [13.473] 65.05 [2.561] 30.00 [1.181] 106.00 [4.173] 32.53 [1.281] 66.00 [2.
Specifications ENGINE IDENTIFICATION NUMBERS Kohler engine identification numbers (model, specification and serial) should be referenced for efficient repair, ordering correct parts, and engine replacement. Model . . . . . . . . . . . . . . . . . . . . . SH265 Courage Engine Horizontal Shaft Numerical Designation Specification . . . . . . . . . . . . . . . SH265-0001 Serial . . . . . . . . . . . . . . . . . . . . .
Specifications TORQUE SPECIFICATIONS4,6 SH255, SH265, SH270 Flywheel Retaining Nut 74 N·m (655 in. lb.) Fuel Tank Mounting Nut Mounting Screw Inlet Fitting 24 N·m (212 in. lb.) 24 N·m (212 in. lb.) 1.5 N·m (13.3 in. lb.) Governor Arm Nut Throttle Control Lever Nut 10 N·m (88.5 in. lb.) 4.5-6 N·m (40-53 in. lb.) Ignition Spark Plug Module Fastener Module Screw Oil Sentry™ Module Screw 27 N·m (20 ft. lb.) 8 N·m (70.8 in. lb.) 10 N·m (88.5 in. lb.) 8 N·m (70.8 in. lb.
Specifications CLEARANCE SPECIFICATIONS4 SH255, SH265, SH270 Camshaft End Play Running Clearance Bore I.D. New Max. Wear Limit 0.025/0.602 mm (0.0010/0.0237 in.) 0.016/0.052 mm (0.0006/0.0020 in.) 14.000/14.018 mm (0.5512/0.5519 in.) 14.048 mm (0.5531 in.) Connecting Rod Crankpin End I.D. @ 21°C (70°F) New Max. Wear Limit Connecting Rod-to-Crankpin Running Clearance New Max. Wear Limit Connecting Rod-to-Crankpin Side Clearance New Max.
Specifications CLEARANCE SPECIFICATIONS4 SH255, SH265, SH270 Cylinder Bore Bore I.D. New Max. Wear Limit Max. Out-of-Round Max. Taper 70.027/70.035 mm (2.757/2.757 in.) 70.200 mm (2.764 in.) 12.7 microns (0.0005 in.) 12.7 microns (0.0005 in.) Cylinder Head Max. Out-of-Flatness 0.1 mm (0.0039 in.) Governor Governor Cross Shaft-to-Crankcase Running Clearance Governor Cross Shaft O.D. New Max. Wear Limit Governor Gear Shaft-to-Governor Gear Running Clearance Governor Gear Shaft O.D. New Max.
Specifications CLEARANCE SPECIFICATIONS4 SH255, SH265, SH270 Valves and Valve Lifters Intake Valve Lash Exhaust Valve Lash Intake Valve Stem-to-Valve Guide Running Clearance Exhaust Valve Stem-to-Valve Guide Running Clearance Intake Valve Stem O.D. New Max. Wear Limit Exhaust Valve Stem O.D. New Max. Wear Limit Intake Valve Stem to Guide New Max. Wear Limit Exhaust Valve Stem to Guide New Max.
Specifications GENERAL TORQUE VALUES English Fastener Torque Recommendations for Standard Applications Bolts, Screws, Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners Into Aluminum Size Grade 2 Tightening Torque: N·m (in. lb.) ± 20% 8-32 2.3 (20) 10-24 3.6 (32) 10-32 3.6 (32) 1/4-20 7.9 (70) 1/4-28 9.6 (85) 5/16-18 17.0 (150) 5/16-24 18.7 (165) 3/8-16 29.4 (260) 3/8-24 33.9 (300) Grade 5 Grade 8 2.8 (25) 4.5 (40) 4.5 (40) 13.0 (115) 15.8 (140) 28.3 (250) 30.
Tools and Aids Certain quality tools are designed to help you perform specific disassembly, repair, and reassembly procedures. By using these tools, 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 a list of tools and their source. NOTE: Not all tools listed are required to service this engine. SEPARATE TOOL SUPPLIERS Kohler Tools Contact your local Kohler source of supply.
Tools and Aids TOOLS Description Hydraulic Valve Lifter Tool For removing and installing hydraulic lifters. Ignition System Tester For testing output on all systems, including CD. Inductive Tachometer (Digital) For checking operating speed (RPM) of an engine. Offset Wrench (K and M Series) For removing and reinstalling cylinder barrel retaining nuts. Oil Pressure Test Kit For testing/verifying oil pressure on pressure lubricated engines.
Tools and Aids FLYWHEEL HOLDING TOOL ROCKER ARM/CRANKSHAFT TOOL A flywheel holding tool can be made out of an old junk flywheel ring gear and used in place of a strap wrench. 1. Using an abrasive cut-off wheel, cut out a six tooth segment of ring gear as shown. 2. Grind off any burrs or sharp edges. 3. Invert segment and place it between ignition bosses on crankcase so tool teeth engage flywheel ring gear teeth.
Troubleshooting TROUBLESHOOTING GUIDE When troubles occur, be sure to check simple causes which, at first, may seem too obvious to be considered. For example, a starting problem could be caused by an empty fuel tank. Some general common causes of engine troubles are listed below and vary by engine specification. Use these to locate causing factors. Engine Cranks But Will Not Start ● Battery connected backwards. ● Blown fuse. ● Carburetor solenoid malfunction. ● Choke not closing.
Troubleshooting Engine Loses Power ● Dirty air cleaner element. ● Engine overheated. ● Excessive engine load. ● Restricted exhaust. ● Faulty spark plug(s). ● High crankcase oil level. ● Incorrect governor setting. ● Low battery. ● Low compression. ● Low crankcase oil level. ● Quality of fuel (dirt, water, stale, mixture). Engine Uses Excessive Amount of Oil ● Loose or improperly torqued fasteners. ● Blown head gasket/overheated. ● Breather reed broken. ● Clogged, broken, or inoperative crankcase breather.
Troubleshooting CRANKCASE VACUUM TEST WARNING Carbon Monoxide can cause severe nausea, fainting or death. Avoid inhaling exhaust fumes. Never run engine indoors or in enclosed spaces. Engine exhaust gases contain poisonous carbon monoxide. Carbon monoxide is odorless, colorless, and can cause death if inhaled. WARNING Rotating Parts can cause severe injury. Stay away while engine is in operation. Keep hands, feet, hair, and clothing away from all moving parts to prevent injury.
Troubleshooting COMPRESSION TEST For Command Twins: A compression test is best performed on a warm engine. Clean any dirt or debris away from base of spark plug(s) before removing them. Be sure choke is off, and throttle is wide open during test. Compression should be at least 160 psi and should not vary more than 15% between cylinders. All other models: These engines are equipped with an automatic compression release (ACR) mechanism.
Air Cleaner/Intake AIR CLEANER These systems are CARB/EPA certified and components should not be altered or modified in any way. Dual-Element Air Cleaner Components A Dual-Element Remove wing nut and air cleaner cover. B Precleaner 1. Remove precleaner from paper element. 2. Replace or wash precleaner in warm water with detergent. Rinse and allow to air dry. 3. Reinstall precleaner over paper element. A C Paper Element 1. Remove wing nut (if equipped) and paper element with precleaner. 2.
Fuel System Typical carbureted fuel system and related components include: ● Fuel tank. ● Fuel lines. ● In-line fuel filter. ● Fuel tank filter. ● Carburetor. ● Fuel strainer screen in carburetor. Fuel tank outlet is located above carburetor inlet, allowing gravity to feed fuel through in-line filter and fuel line to carburetor. Fuel then enters carburetor through a fuel shut-off valve and a fine screen/sediment bowl, and then to carburetor float bowl.
Fuel System CARBURETOR WARNING Explosive Fuel can cause fires and severe burns. Do not fill fuel tank while engine is hot or running. These engines are equipped with a fixed main jet carburetor. Carburetor is designed to deliver correct fuelto-air mixture to engine under all operating conditions. Idle mixture is set at factory and cannot be adjusted.
Fuel System Troubleshooting-Carburetor Related Causes Condition Engine starts hard, runs rough, or stalls at idle speed. Engine runs rich (indicated by black, sooty exhaust smoke, misfiring, loss of speed and power, governor hunting, or excessive throttle opening). Engine runs lean (indicated by misfiring, loss of speed and power, governor hunting, or excessive throttle opening). Fuel leaks from carburetor. Possible Cause Low idle fuel mixture (some models)/ speed improperly adjusted. Clogged air cleaner.
Fuel System • Inspect carburetor body for cracks, holes, and other wear or damage. • Inspect float for cracks, holes, and missing or damaged float tabs. Check float hinge and shaft for wear or damage. • Inspect fuel inlet needle and seat for wear or damage. 1. Perform removal procedures for appropriate air cleaner and carburetor outlined in Disassembly. 2. Clean exterior surfaces of dirt or foreign material before disassembling carburetor.
Governor System GOVERNOR Governor Components A J I I C E F K H D G B A Control Assembly B Nut C Governor Spring D Throttle Link E Dampening Spring F Throttle Control Lever G Governor Lever H Cup I Washer J Governor Gear K Governor Gear Shaft Governed speed setting is determined by position of throttle control. It can be variable or constant, depending on engine application. Governor is designed to hold engine speed constant under changing load conditions.
Lubrication System These engines use a splash lubrication system, supplying necessary lubrication to crankshaft, camshaft, connecting rod and valve train components. Lubrication Components A B C A Dipstick C B Oil Fill Plug OIL RECOMMENDATIONS Refer to Maintenance. CHECK OIL LEVEL NOTE: To prevent extensive engine wear or damage, never run engine with oil level below or above operating range indicator on dipstick. Ensure engine is cool. Clean oil fill/dipstick areas of any debris. 1.
Electrical System SPARK PLUGS CAUTION Electrical Shock can cause injury. Do not touch wires while engine is running. Spark Plug Component and Details Inspection Inspect each spark plug as it is removed from cylinder head. Deposits on tip are an indication of general condition of piston rings, valves, and carburetor. Normal and fouled plugs are shown in following photos: Normal A B Plug taken from an engine operating under normal conditions will have light tan or gray colored deposits.
Electrical System ELECTRONIC IGNITION SYSTEM Inductive Discharge Ignition System Components Carbon Fouled J I F H B Soft, sooty, black deposits indicate incomplete combustion caused by a restricted air cleaner, over rich carburetion, weak ignition, or poor compression. Overheated Chalky, white deposits indicate very high combustion temperatures. This condition is usually accompanied by excessive gap erosion.
Electrical System Electronic Ignition Systems and Oil Sentry™ Tests 1. Disconnect cap from spark plug and attach it to terminal end of spark tester. Attach tester spring clip to a good ground, not to spark plug. Turn ignition/key switch ON and crank engine while observing firing tip of tester. Condition Tester is firing. Tester doesn't fire. Conclusion Ignition system is good. Install a new spark plug and try to start engine. If it still will not start, check other possible causes (fuel, compression, etc.
Electrical System 6. Set an ohmmeter to Rx1 scale and zero meter. Test ignition/key switch as follows. a. Trace two black leads from on/off switch and separate them from any connections. Connect ohmmeter leads to switch leads, and check for continuity in both switch positions. Condition Conclusion Continuity should be indicated when and only when switch is in OFF position. Replace switch for any other results.
Starter System NOTE: Do not crank engine continuously for more than 10 seconds. Allow a 60 second cool down period between starting attempts. Failure to follow these guidelines can burn out starter motor. NOTE: If engine develops sufficient speed to disengage starter but does not keep running (a false start), engine rotation must be allowed to come to a complete stop before attempting to restart engine.
Starter System 4. Use a known, good, fully-charged battery and jumper cables to test starter motor. Be sure transmission is in neutral and PTO is OFF. Remove heavy lead from post terminal on starter. Connect one end of positive jumper cable to post terminal and connect other end to positive terminal of battery. Connect one end of negative jumper cable to negative terminal of battery. Touch other end of negative jumper cable to a bare surface on crankcase or to starter housing.
Starter System RETRACTABLE STARTERS WARNING Uncoiling Spring can cause severe injury. Wear safety goggles or face protection when servicing retractable starter. Retractable starters contain a powerful, recoil spring that is under tension. Always wear safety goggles when servicing retractable starters and carefully follow instructions in Retractable Starter for relieving spring tension. Retractable Starter Components B A A Kit, Pawl Repair B Remove Starter 1.
Disassembly/Inspection and Service WARNING Accidental Starts can cause severe injury or death. Disconnect and ground spark plug lead(s) before servicing. Before working on engine or equipment, disable engine as follows: 1) Disconnect spark plug lead(s). 2) Disconnect negative (–) battery cable from battery.
Disassembly/Inspection and Service Clean all parts thoroughly as engine is disassembled. Only clean parts can be accurately inspected and gauged for wear or damage. There are many commercially available cleaners that will quickly remove grease, oil, and grime from engine parts. When such a cleaner is used, follow manufacturer’s instructions and safety precautions carefully. Make sure all traces of cleaner are removed before engine is reassembled and placed into operation.
Disassembly/Inspection and Service Remove air cleaner gasket and slide carburetor off mounting studs while disconnecting throttle linkage and dampening spring. Remove carburetor to insulator gasket, insulator, and insulator to cylinder head gasket. Remove External Throttle, Governor and Choke Linkage 1. Mark hole in which governor spring is attached and loosen nut securing governor lever arm to governor shaft.
Disassembly/Inspection and Service Remove Valve Cover/Breather, Rocker Arms, Push Rods and Cylinder Head Assembly NOTE: Mark location of push rods and any other part removed that will be reused. Valve Cover with Gasket 1. Remove screws and remove valve cover and gasket from engine. Breather assembly is inside valve cover. 2. Remove screws securing cylinder shroud and remove cylinder shroud. 3. Loosen and remove rocker arm lock nuts and adjuster nuts. Remove rocker arms and push rods. 4. Remove spark plug.
Disassembly/Inspection and Service Valve Details B D D C D A E Item Dimension Intake Exhaust A Head Diameter—Specification 25 mm + 0.1 mm (0.9842 in. + 0.0039 in.) 24 mm + 0.1 mm (0.9449 in. + 0.0039 in.) Head Diameter—Maximum 25.1 mm (0.9881 in.) 24.1 mm (0.9488 in.) Head Diameter—Service Limit 24.9 mm (0.9803 in.) 23.9 mm (0.9409 in.) Stem Diameter—Specification 5.5 mm (0.217 in.) 5.438 mm (0.214 in.) B C Stem Diameter—Maximum 5.491 mm (0.216 in.) 5.430 mm (0.214 in.
Disassembly/Inspection and Service Inspection and Service After cleaning, check flatness of cylinder head and corresponding top surface of crankcase, using a surface plate or piece of glass and feeler gauge. Maximum allowable out of flatness is 0.1 mm (0.0039 in.). Carefully inspect valve mechanism parts. Inspect valve springs and related hardware for excessive wear or distortion. Check valves and valve seats for evidence of deep pitting, cracks, or distortion.
Disassembly/Inspection and Service Crankcase Components S T U R O P Q N G H V F K I L J M E B D C A A Closure Plate Oil Seal B Closure Plate Bearing C Closure Plate D Gasket E Camshaft F Crankshaft G Oil Sentry™ Float Switch H End Cap I Connecting Rod J Piston Pin Retainer K Piston Pin L Piston M Piston Ring Set N Tappet O Governor Cup P Governor Washer Q Governor Shaft R Governor Gear S Governor Cross Shaft T Crankcase Bearing U Crankcase Oil Seal V
Disassembly/Inspection and Service Remove Camshaft and Valve Tappets 1. Remove camshaft by pulling it straight out of crankcase. 2. Remove valve tappets by pulling straight out of crankcase. Mark their positions. Inspection and Service Inspect gear teeth of camshaft. If teeth are badly worn or chipped, or if some are missing, replacement of camshaft will be necessary. If unusual wear or damage is evident on either camshaft lobes or mating tappets camshaft and both tappets must be replaced.
Disassembly/Inspection and Service Detonation damage occurs when a portion of fuel charge ignites spontaneously from heat and pressure shortly after ignition. This creates 2 flame fronts, which meet and explode to create extreme hammering pressures on a specific area of piston. Detonation generally occurs from using low octane fuels. Preignition or ignition of fuel charge before timed spark can cause damage similar to detonation. Preignition damage is often more severe than detonation damage.
Disassembly/Inspection and Service 1. Oil control ring assembly (bottom groove): Install expander first then bottom rail and top rail last. Make sure ends of expander are not overlapped. Adjust ring gaps. 2. Middle compression ring (center groove): Install middle compression ring using a piston ring expander tool. Make sure identification mark is up or colored dye stripe (if contained) is left of end gap. Adjust ring gaps. 3.
Reassembly Crankcase Components S T W A A R O V P Q N G H U F K L J I M E B D C A A Oil Seal B Closure Plate Bearing C Closure Plate D Gasket E Camshaft F Crankshaft G Oil Sentry™ Float Switch H End Cap I Connecting Rod J Piston Pin Retainer K Piston Pin L Piston M Piston Ring Set N Tappet O Governor Cup P Governor Washer Q Governor Shaft R Governor Gear S Governor Cross Shaft T Crankcase Bearing U Dowel Pin V Oil Seal Depth W Outer Surface N
Reassembly 5. Apply a light coating of lithium grease to seal lips after installing. Install Governor Assembly 1. Install governor shaft through gear and add thrust washer to shaft. 2. Install governor gear assembly into crankcase using a press, or a drift with light taps, until tip of shaft is 78.862 mm (3.105 in.) below machined gasket surface of crankcase. 3. Install thrust washer and cup on governor gear shaft. 4.
Reassembly Install Closure Plate Install Flywheel Torque Sequence CAUTION Damaging Crankshaft and Flywheel can cause personal injury. 1 6 4 Using improper procedures can lead to broken fragments. Broken fragments could be thrown from engine. Always observe and use precautions and procedures when installing flywheel. 3 2 5 NOTE: Make sure governor lever is against cup on governor gear assembly. 1. Check to be sure sealing surfaces of crankcase and closure plate are clean and free of nicks or burrs.
Reassembly 8. Connect kill wire to ignition module bottom blade terminal and route wire lead across top of crankcase.
Reassembly d. Hold adjuster from turning and tighten locknut. Torque locknut to 10 N·m (88.5 in. lb.). e. Recheck that clearance is correct. 5. Set gap of new spark plug to 0.76 mm (0.030 in.). 6. Install spark plug in cylinder head and torque to 27 N·m (20 ft. lb.). Valve Cover with RTV Install Valve Cover Valve Cover Torque Sequence 3 2 A 1 4 Valve Cover with Gasket 1. Make sure sealing surfaces of valve cover and cylinder head are clean, and free of any nicks or burrs. 2.
Reassembly Blower Housing/Control Panel Components F E C D G B A M L I K J H A Governor Lever B Nut C Governor Spring D Throttle Link E Dampening Spring F Control Assembly G Carburetor H Retractable Starter I On/Off Wiring Harness Bullet Connector J Blower Housing K Oil Sentry™ Wiring Harness Bullet Connector L Oil Sentry™ Module M Oil Sentry™ Bracket Install Throttle Plate Install throttle plate with screws. Install Blower Housing 1.
Reassembly Install Retractable Starter 1. Install retractable starter on blower housing using screws. Finger tighten screws only. 2. Pull rope handle to engage pawls and center starter to drive cup. Hold in this position and torque screws to 5.4 N·m (47.8 in. lb.).
Reassembly Install Throttle Lever, Governor Lever, Throttle Link, Dampening Spring, and Governor Spring 1. Install nylon washer and wave spring to throttle plate. 2. Connect spring to throttle lever and throttle plate. Install throttle lever to throttle plate. Install tabbed washer (with tab engaged in slot) and secure with nut. 3. Torque nut to 5.4 N·m (47.8 in. lb.). 4. Install governor lever onto shaft. 5. Connect dampening spring and throttle link to governor lever.
18 690 01 Rev. G KohlerEngines.
Reassembly Install Oil SentryTM Module 1. Install Oil Sentry™ module and secure with screw. 2. Connect electrical leads for Oil Sentry™ module. Install Fuel Tank 1. Route fuel line across top of engine toward carburetor while positioning fuel tank on mounting brackets. 2. Secure with screw on inner mounting bracket. 3. Install nuts on fuel tank studs. 4. Torque fuel tank screw and nuts to 24 N·m (212 in. lb.). 5. Position fuel line in clip at carburetor and connect fuel line to shut-off valve on carburetor.
18 690 01 Rev. G KohlerEngines.
KohlerEngines.com 18 690 01 Rev.
18 690 01 Rev. G KohlerEngines.
© 2021 by Kohler Co. All rights reserved. 56 KohlerEngines.com 18 690 01 Rev.
