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SV470-SV620 Service Manual

1. Overheated LL Chalky white deposits indicate very high combustion temperatures This condition is usually accompanied by excessive gap erosion Lean carburetor settings an intake air leak or incorrect spark timing are normal causes for high combustion temperatures BATTERY A 12 volt battery with 250 cold cranking amps cca is generally recommended for starting in all conditions A smaller capacity battery is often sufficient if an application is started only in warmer temperatures Actual cold cranking reguirement depends on engine size application and starting temperatures Cranking requirements increase as temperatures decrease and battery capacity shrinks Refer to equipment s operating instructions for specific battery requirements Battery Size Recommendations If battery charge is insufficient to turn over engine recharge battery Battery Maintenance Regular maintenance is necessary to prolong battery life Battery Test To test battery follow manufacturer s instructions ELECTRONIC IGNITION SYSTEM Ignition System Components _ e wo C Flywheel D Magnet E SparkPlug F open Module G KillTerminal H Spark Plug Boot _ Spark Plug Terminal There is 1 type of ignition system used on these engines This system uses an ignition module which energizes spark plug This ignition system is designed to be trouble free for life of engine Other than periodical
2. CYLINDER LEAKDOWN TEST A cylinder leakdown test can be a valuable alternative to a compression test By pressurizing combustion chamber from an external air source you can determine if valves or rings are leaking and how badly Cylinder leakdown tester is a relatively simple inexpensive leakdown tester for small engines This tester includes a quick connect for attaching adapter hose and a holding tool 1 Run engine for 3 5 minutes to warm it up 2 Remove spark plug s and air filter from engine 3 Rotate crankshaft until piston of cylinder being tested is at top dead center TDC of compression stroke Hold engine in this position while testing Holding tool supplied with tester can be used if PTO end of crankshaft is accessible Lock holding tool onto crankshaft Install a 3 8 in breaker bar into hole slot of holding tool so it is perpendicular to both holding tool and crankshaft PTO If flywheel end is more accessible use a breaker bar and socket on flywheel nut screw to hold it in position An assistant may be needed to hold breaker bar during testing If engine is mounted in a piece of equipment it may be possible to hold it by clamping or wedging a driven component Just be certain that engine cannot rotate off of TDC in either direction Install adapter into spark plug hole but do not attach it to tester at this time Turn regulator knob completely counterclockwise Connect an air source of at least 50 psi to tester Tur
3. Crankcase breather clogged or inoperative NOTE If breather is integral part of valve cover and cannot be serviced separately replace valve cover and recheck pressure Disassemble breather clean parts thoroughly check sealing surfaces for flatness reassemble and recheck pressure Seals and or gaskets leaking Loose or improperly torque Replace all worn or damaged seals and gaskets Make fasteners sure all fasteners are tightened securely Use appropriate torque valves and sequences when necessary Piston blow by or leaky valves confirm by inspecting Recondition piston rings cylinder bore valves and components valves guides Restricted exhaust Check exhaust screen spark arrestor if equipped Clean or replace as needed Repair or replace any other damaged restricted muffler or exhaust system parts 18 KohlerEngines com 20 690 01 Rev 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 lt is difficult to obtain an accurate compression reading because of ACR mechanism As an alternative use cylinder leakdown test described below
4. 15 9 mm 5 8 in Refer to Maintenance for Repairs Service Parts Service Clean out spark plug recess Remove plug and replace 1 Check gap using wire feeler gauge Adjust gap to 0 76 mm 0 03 in 2 Install plug into cylinder head 3 Torque plug to 27 N m 20 ft Ib 20 690 01 Rev Electrical System Inspection Inspect each spark plug as it is removed from cylinder head Deposits on tip are an indication of general condition of piston rings valves and carburetor Normal and fouled plugs are shown in following photos Normal Plug taken from an engine operating under normal conditions will have light tan or gray colored deposits If center electrode is not worn plug can be set to proper gap and reused Worn Ei On a worn plug center electrode will be rounded and gap will be greater than specified gap Replace a worn spark plug immediately Wet Fouled A wet plug is caused by excess fuel or oil in combustion chamber Excess fuel could be caused by a restricted air cleaner a carburetor problem or operating engine with too much choke Oil in combustion chamber is usually caused by a restricted air cleaner a breather problem worn piston rings or valve guides KohlerEngines com 35 Electrical System Carbon Fouled ww ci Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich carburetion weak ignition or poor compression
5. Ib into used holes 3 Snap debris screen onto cooling fan 14 KohlerEngines com Install Air Cleaner Element Precleaner and Air Cleaner Cover 1 Install air cleaner element with pleated side out Seat rubber seal onto all edges of air cleaner base 2 Install precleaner if equipped into upper section of air cleaner cover 3 Install air cleaner cover and secure with two retaining knobs Install Muffler 1 Install gasket muffler and nuts on exhaust port studs Leave nuts slightly loose 2 If an auxiliary muffler bracket is used install M6 screw s into bracket 3 Torque nuts to 24 4 N m 216 in Ib Torque screws to 7 5 N m 65 in Ib Install Drain Plug Oil Filter and Oil 1 Install oil drain plug Torque plug to 14 N m 125 in Ib 2 Place new filter in shallow pan with open end up Fill with new oil until oil reaches bottom of threads Allow 2 minutes for oil to be absorbed by filter material 3 Apply a thin film of clean oil to rubber gasket on new filter 4 Refer to instructions on oil filter for proper installation 5 Fill crankcase with new oil Level should be at top of indicator on dipstick 6 Reinstall oil fill cap dipstick and tighten securely Prepare Engine for Operation Engine is now completely reassembled Before starting or operating engine be sure following have been done 1 Al hardware is tightened securely 2 Oil drain plug Oil Sentry pressure switch if
6. Ps CN p iO o k Crankshaft Crank Gear Key D e Washer e map H Osa Piston Ring Set o First Generation Second Generation Balance Weight Balance Weight Inspection and Service Remove Connecting Rod ana Piston Check bearing area big end for score marks and NOTE Ifa carbon ridge is present at top of bore use a excessive wear Service replacement connecting rods ridge reamer to remove it before attempting to are available in STD crankpin size remove piston Rotate crankshaft so rod journal is in 9 o clock position Remove screws and connecting rod cap Carefully push connecting rod and piston away from crankshaft and out of cylinder bore Remove Piston from Connecting Rod Remove wrist pin retainer and wrist pin Separate piston from connecting rod oN 98 KohlerEngines com 20 690 01 Rev Piston and Rings Inspection Piston and Rings Components and Details EM Piston Ring B End Gap Top pm Center ie Compression Ring re Rais n Expander Oil Control Ring 3 Piece Scuffing and scoring of pistons and cylinder walls occurs when internal temperatures approach welding point of piston Temperatures high enough to do this are created by friction which is usually attributed to improper lubrication and or overheating of engine Normally very little wear takes place in piston boss piston pin area If original piston and connecting rod can be reused after n
7. REPAIRS SERVICE PARTS Kohler genuine service parts can be purchased from Kohler authorized dealers To find a local Kohler authorized dealer visit KohlerEngines com or call 1 800 544 2444 U S and Canada 20 690 01 Rev KohlerEngines com 3 Maintenance OIL RECOMMENDATIONS We recommend use of Kohler oils for best performance Other high quality detergent oils including synthetic of API American Petroleum Institute service class SJ or higher are acceptable Select viscosity based on air temperature at time of operation as shown in table below 32 40 50 60 0 10 Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent NOTE E15 E20 and E85 are NOT approved and should NOT be used effects of old stale or contaminated fuel are not warrantable Fuel must meet these requirements e Clean fresh unleaded gasoline e Octane rating of 87 R M 2 or higher e Research Octane Number RON 90 octane minimum e Gasoline up to 10 ethyl alcohol 90 unleaded is acceptable e Methyl Tertiary Butyl Ether MTBE and unleaded gasoline blend max 15 MTBE by volu
8. equipped and a new oil filter are installed 3 Crankcase is filled with correct amount weight and type of oil 20 690 01 Rev Reassembly Testing Engine It is recommended engine be operated on a test stand or bench prior to installation in piece of eguipment 1 Set engine up on a test stand Install an oil pressure gauge Start engine and check to be certain oil pressure 5 psi or more is present 2 Run engine for 5 10 minutes between idle and mid range Adjust throttle and choke controls and high speed setting as necessary Make sure maximum engine speed does not exceed 3300 RPM Adjust carburetor idle fuel needle and or idle speed screw as necessary Refer to Fuel System and Governor System 20 690 01 Rev KohlerEngines com Ya 1P20 690 Ol 2014 by Kohler Co All rights reserved 6 50531 98601 e 76 KohlerEngines com 20 690 01 Rev
9. main nozzles can be removed through bottom of main towers Note orientation direction of nozzles End with 2 raised shoulders should be out down adjacent to main jets Save parts for cleaning and reuse 6 Position of slow jet varies and is removable only on some styles of carburetors See correct illustration for corresponding style of carburetor showing location On two barrel carburetors slow jets may be sized to specific side Mark or tag jets for proper reassembly Note small O ring on bottom of each jet Save parts for cleaning and reuse unless a jet kit is also being installed Clean slow jets using compressed air Do not use wire or carburetor cleaner Carburetor is now disassembled for appropriate cleaning and installation of parts in overhaul kit See instructions provided with repair kits for more detailed information High Altitude Operation Engines may require a high altitude carburetor kit to ensure correct engine operation at altitudes above 1219 meters 4000 ft To obtain high altitude kit information or to find a Kohler authorized dealer visit KohlerEngines com or call 1 800 544 2444 U S and Canada This engine should be operated in its original configuration below 1219 meters 4000 ft as damage may occur if high altitude carburetor kit is installed and operated below 1219 meters 4000 ft UNITIZED THROTTLE AND CHOKE CONTROL Some engines are equipped with a unitized throttle and choke control This as
10. 50 mm 1 750 in plus or minus 0 101 mm 0 004 in above crankcase boss 2 Install new governor regulating pin and governor gear assembly 3 Make sure governor gear assembly rotates freely 4 Check that timing marks are still aligned 5 Install a new closure plate gasket and install closure plate Torque fasteners to 24 5 N m 216 in Ib 6 Complete engine reassembly following Reassembly procedures 7 When engine reassembly is completed reset initial governor adjustment according to procedure in Governor System Closure Plate and Passage Cover Inspection and Service Passage Cover Torque Sequence NOTE Passage cover with 3 fasteners does not require a torque sequence If disassembly was performed inspect and ensure oil passages in closure plate and passage cover are completely clean and not obstructed in any way Check straightness of passage cover if required against a flat surface Use a new passage cover gasket and install passage cover onto closure plate Reinstall mounting screws and torque to 4 0 N m 35 in lb following sequence Passage cover with 3 fasteners does not require a torque sequence Remove Cam Gears Cam Shafts and Oil Pump NOTE ACR weight and spring normally captured by thrust washer and installation of closure plate will fall out if exhaust cam gear is turned upside down Cam gear assemblies may contain either two or four rivets NOTE 20 690 01 Rev NOTE Engi
11. 8 16 3 8 24 Noncritical Fasteners Into Aluminum Tightening Torque N m ft Ib 10 21 7 16 27 1 20 47 5 35 66 4 49 81 4 60 M12 36 6 27 47 5 35 82 7 61 116 6 86 139 7 103 M14 58 3 43 76 4 56 131 5 97 184 4 136 219 7 162 Torque Conversions N m in Ib x 0 113 in lb N m x 8 85 N m ft Ib x 1 356 ft lb N m x 0 737 12 KohlerEngines com 20 690 01 Rev 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 SEPARATE TOOL SUPPLIERS Kohler Tools SE Tools Design Technology Inc Contact your local Kohler source of 415 Howard St 768 Burr Oak Drive supply Lapeer MI 48446 Westmont IL 60559 Phone 810 664 2981 Phone 630 920 1300 Toll Free 800 664 2981 Fax 630 920 0011 Fax 810 664 8181 TOOLS Description Source Part No Alcohol Content Tester Kohler 25 455 11 S For testing alcohol content in reformulated oxygenated fuels Camshaft Endplay Plate SE Tools KLR 82405 For checking camshaft endplay Camshaft Seal Protector Aegis SE Tools KLR 82417 For protecting seal during camshaft installation Cylinder Leakdown Tester Kohler 25 761 05 S For checking combustion retention and if c
12. Carburetor Servicing NOTE Main and slow jets are fixed and size specific and can be removed if required Fixed jets for high altitudes are available e Inspect carburetor body for cracks holes and other wear or damage e Inspect float for cracks holes and missing or damaged float tabs Check float hinge and shaft for wear or damage e Inspect fuel inlet needle and seat for wear or damage e Inspect spring loaded choke plate to make sure it moves freely on shaft 1 Perform removal procedures for appropriate air cleaner and carburetor outlined in Disassembly 2 Clean exterior surfaces of dirt or foreign material before disassembling carburetor Remove bowl retaining screws or solenoid assembly on most single cylinder engines and carefully separate fuel bowl from carburetor Do not damage fuel bowl O rings Transfer any remaining fuel into an approved container Save all parts Fuel can also be drained prior to bowl removal by loosening removing bowl drain screw 3 Remove float pin some carburetors may have a screw which requires removal and inlet needle Seat for inlet needle is not serviceable and should not be removed 4 Clean carburetor bowl and inlet seat areas as required 26 KohlerEngines com 5 Garefully remove main jets from carburetor For two barrel carburetors note and mark jets by location for proper reassembly Main jets may be size side specific After main jets are removed on some carburetors
13. Explosive Fuel can cause fires and severe burns Do not fill fuel tank while engine is hot or running Gasoline is extremely flammable and its vapors can explode if ignited Store gasoline only in approved containers in well ventilated unoccupied buildings away from sparks or flames Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition Never use gasoline as a cleaning agent NOTE It is recommended that a new governor lever be installed whenever removal is performed 1 Shut off fuel supply Disconnect fuel line from carburetor inlet fitting If a fuel pump is used disconnect pulse line from fitting on closure plate 2 Remove heat deflector or carburetor spacer heat shield if equipped mounting screw and special washer which also secures ground lead for fuel shut off solenoid if so equipped 3 If carburetor uses a fuel solenoid carefully cut plastic tie strap and disconnect fuel solenoid lead from wiring harness 4 Slide carburetor outward and disconnect throttle and choke linkages 5 Mark mounted position of speed control bracket in slotted holes and remove screws securing speed control bracket to closure plate Note or mark governor spring hole for correct installation later Unhook governor spring then remove control bracket with fuel pump attached if equipped and linkages from engine 6 Loosen nut and remove governor lever from governor cross shaft 7 Remove carb
14. Plate Te Gasket D Oi Passage Cover_ E Cam Gears F Thrust washer Le Cam Levers 8 Cam Shaft Exhaust 1 Closure Pate Gasket J Gerotor Gears K Opus L engt Pn M Cam Shaft intake N Regulating Pin o GovemorGear P Governor Gear Shaft Remove Closure Plate q J L 1 Remove screws securing closure plate to crankcase Note location and position of any attached clips or clamps 2 A gasket is used between closure plate and crankcase lf necessary carefully tap on bosses for starter or oil filter with a soft faced mallet to loosen Do not pry on gasket surfaces of crankcase or oil pan as this can cause damage resulting in leaks 3 Remove closure plate assembly and gasket KohlerEngines com 59 Disassembly Inspection and Service 4 If wiring harness needs to be separated from closure plate pry open clamps and pull out through slot Disassemble Closure Plate NOTE Governor gear is held onto shaft by small molded tabs in gear When gear is removed these tabs are destroyed and gear must be replaced Governor gear removal is required for closure plate disassembly and cleaning of oil passages 1 Remove governor gear and regulating pin assembly Gently pry upward using blades of two small screwdrivers 2 Remove screws securing oil passage cover to closure plate Remove cover and gasket Governor Gear and Shaft Inspection Inspect governor gear teeth Look for any evidence of wor
15. and valve cover a Compress valve springs using a valve spring compressor and remove keepers Remove Cylinder Head b Remove compressor then remove valve spring 1 Loosen inner set screws T15 TORX and back off caps valve springs and valves rocker arm adjusting nuts Remove push rods and mark them so they can be reinstalled in same location 20 690 01 Rev KohlerEngines com 53 Disassembly Inspection and Service Model SV470 480 530 540 590 600 610 Valve Details d EXHAUST VALVE Ss INTAKE VALVE Dimension Intake Exhaust A Seat Angle 89 89 Guide Depth 10 20 mm 6 2mm C Guide I D 6 038 6 058 mm 6 038 6 058 mm Valve Head Diameter 37 625 37 375 mm 32 129 32 375 mm Valve Face Angle 45 45 Valve Margin Min 1 5mm 1 5 mm G Valve Stem Diameter 5 982 6 00 mm 5 90 5 988 mm Model SV620 Valve Details INTAKE VALVE Dimension Intake Exhaust A Seat Angle 89 89 Seat Angle 111 109 131 129 C Seat Angle 61 59 51 49 Guide Depth 10 20 mm 6 2 mm Guide I D 6 038 6 058 mm 6 038 6 058 mm Valve Head Diameter 37 625 37 375 mm 32 125 32 375 mm Valve Face Angle 45 45 Valve Face Angle 39 275 39 525 33 675 33 925 Valve Face Angle 60 60 J Valve Margin Min 1 7 mm 1 7 mm K Valve Stem Diameter 5 982 6 000 mm 5 90 5 988 mm 94 KohlerEngines com 20 690 01 Rev Inspection and Service Carefully inspect valve mechanism parts Inspect valve springs and related hardware for exc
16. by following steps 3 and 4 Push move choke control in down until it bottoms Choke lever and link should be to right at end of its travel with linkage free so engine does not run on partial choke KohlerEngines com Starting an Engine Equipped with Separate Control Cables 1 2 Os Place throttle control midway between slow and fast positions Place choke control into on position Start engine For a Cold Engine Gradually return choke control to off position after engine starts and warms up Engine equipment may be operated during warm up period but it may be necessary to leave choke partially on until engine warms up For a Warm Engine Return choke to off position as soon as engine starts Changing High Speed RPM on Engines with Separate Controls Increase or Decrease RPM Speed Control Bracket Details Check that governor spring and installation matches intended high speed RPM operating range Start engine move application throttle lever to full throttle fast and loosen mounting screws of main speed control bracket to allow repositioning To increase RPM Move speed control bracket towards carburetor To decrease RPM Move speed control bracket away from carburetor Check RPM with a tachometer and tighten screws when correct setting has been obtained To ensure that RPM has been obtained move throttle lever to low idle slow then back to full throttle fast position and check RPM with
17. caused by a hot spot in combustion chamber from sources such as glowing carbon deposits blocked fins improperly seated valve or wrong spark plug Replacement pistons are available in STD and 0 08 mm 0 003 in oversize which include new rings and piston pins Service replacement piston ring sets are also available separately Always use new piston rings when installing pistons Never reuse old rings Remove Piston Rings 1 Remove top and center compression rings using a ring expander 2 Remove oil control ring rails then remove spacer Some important points to remember when servicing piston rings 1 Cylinder bore must be deglazed before service ring sets are used 2 If cylinder bore is within wear limits refer to Specifications and old piston is within wear limits free of score or scuff marks old piston may be reused 3 Remove old rings and clean up grooves Never reuse old rings 4 Before installing rings on piston place each of top two rings in its running area in cylinder bore and check end gap Compare to listed specifications Clearance Specifications Top and Middle Compression Ring End Gap New Bore Top Ring 0 15 0 40 mm 0 006 0 016 in 0 30 0 55 mm 0 012 0 022 in 0 77 mm 0 030 in Middle Ring Max Used Bore After installing new compression top and middle rings on piston check piston to ring side clearance Maximum recommended side clearance for each ring is 0 04 mm 0 0016 in
18. cover as shown noting RTV overlap area 3 Position cover on cylinder head Position any brackets mounted on valve cover and start seven mounting screws KohlerEngines com 69 Reassembly 4 Torque valve cover screws to 11 0 N m 95 in Ib into new holes or 7 5 N m 65 in Ib into used holes using sequence shown Flywheel Ignition Components A Flywheel Screw B Washer e Fan Mounting Plate D Fan E Magnet F Flywheel e ignition modue H Stator 1 FiywheetKey J Pulse Line Fiting Install Stator and Wiring Harness Install Stator 1 Position stator onto mounting bosses so leads lay in channel and recess of closure plate They will become captured when blower housing is installed lf a clamp was used to retain leads remove screw in No 13 location and install clamp Hold clamp in position and torque screw to 24 5 N m 216 in Ib 70 KohlerEngines com 2 Install two screws to secure stator and torque to 6 0 N m 55 in Ib into new holes or 4 0 N m 35 in Ib into used holes Install Wiring Harness Check locking tang on terminal of violet B wiring harness lead is angled upward Insert terminal into center location of rectifier regulator plug connector until it locks into place If not already inserted two AC leads from stator go in outer locations Install Pipe Plug or Fitting and Pulse Line for Fuel Pump 1 Apply pipe sealant with Teflon Loctite PST 592 Thread
19. instructions on its proper and safe use Never use gasoline as a cleaning agent After inspecting external condition of engine clean engine thoroughly before disassembly Clean individual components 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 Even small amounts of these cleaners can quickly break down lubricating properties of engine oil KohlerEngines com 17 Troubleshooting CRANKCASE VACUUM TEST Ac CP Carbon Monoxide can cause severe nausea fainting or death oe Avoid inhaling exhaust fumes Engine exhaust gases contain poisonous carbon Keep hands feet hair and clothing away from all monoxide Carbon monoxide is odorless colorless moving parts to prevent injury Never operate engine and can cause death if inhaled with covers shrouds or guards removed Rotating Parts can cause severe injury Stay away while engine is in operation A partial vacuum should be present in crankcase when engine is operating Pressure in crankcase normally caused by a clogged or improperly assembled breather can cause oil to be forced out at oil seals gaskets
20. is disengaged or placed or in neutral This is especially important on equipment with hydrostatic drive Transmission must be exactly in neutral to prevent resistance which could keep engine from starting Check for seized engine components such as bearings connecting rod and piston 44 KohlerEngines com 20 690 01 Rev INERTIA DRIVE ELECTRIC STARTERS Inertia Drive Electric Starter Thru Bolts Brush Carrier Assembly Insulating Washer Commutator End Cap A ET Amawe EN 7 ES w ES Frame Assembly Thrust Washer Drive End Cap Hex Flange Nut L Drive Nut Collar H Anti Drift Spring Retaining Ring KohlerEngines com 45 20 690 01 Rev Starter System When power is applied to starter armature rotates As armature rotates drive pinion moves out on splined drive shaft and into mesh with flywheel ring gear When pinion reaches end of drive shaft it rotates flywheel and cranks engine When engine starts flywheel rotates faster than starter armature and drive pinion This moves drive pinion out of mesh with ring gear and into retracted position When power is removed from starter armature stops rotating and drive pinion is held in retracted position by anti drift spring Starter Drive Service It is not necessary to completely disassemble starter to service drive components 1 Disassemble retaining ring use tool 2 Grasp spring retainer and push it toward starter compressing anti drift spring and ex
21. or other available spots Crankcase vacuum is best measured with either a water manometer or a vacuum gauge Complete instructions are provided in kits To test crankcase vacuum with manometer To test crankcase vacuum with vacuum pressure gauge 1 Insert rubber stopper into oil fill hole Be sure pinch 1 Remove dipstick or oil fill plug cap clamp is installed on hose and use tapered adapters 2 Install adapter into oil fill dipstick tube opening to connect hose between stopper and one upside down over end of a small diameter dipstick manometer tube Leave other tube open to tube or directly into engine if a tube is not used atmosphere Check that water level in manometer is Insert barbed gauge fitting into hole in stopper at O line Make sure pinch clamp is closed l l 3 Run engine and observe gauge reading 2 Start engine and run no load high speed l 3 o Seen terienel idad Analog tester needle movement to left of 0 is a gree a emcee ee vacuum and movement to right indicates a pressure Level in engine side should be a minimum of 10 2 Digital tester depress test button on top of tester cm 4 in above level in open side m H SE Crankcase vacuum should be a minimum of 10 2 cm Ge Me aA 4 in of water If reading is below specification or if Red a n dee D pressure is present check table below for possible p p i causes and conclusions below 4 Close pinch clamp before stopping engine Condition Conclusion
22. 0 003 in 5 975 6 012 mm 0 2352 0 2367 in 5 962 mm 0 2347 in 0 09 0 16 mm 0 0035 0 0063 in 5 99 6 00 mm 0 2358 0 2362 in 5 977 mm 0 02353 in Ignition Spark Plug Gap Module Air Gap Oil Pump Pump Gears to Crankcase Side Clearance Piston Piston Rings and Piston Pin Pin Bore I D New Max Wear Limit Pin O D New 0 76 mm 0 030 in 0 203 0 305 mm 0 008 0 012 in 0 165 0 315 mm 0 0065 0 0124 in 22 006 22 012 mm 0 8685 0 8666 in 22 025 mm 0 8671 in 21 995 22 0 mm 0 8659 0 8661 in 21 994 mm 0 8658 in 0 04 mm 0 0016 in 0 04 mm 0 0016 in Values are in Metric units Values in parentheses are English equivalents Max Wear Limit Top Compression Ring to Groove Side Clearance Middle Compression Ring to Groove Side Clearance 10 KohlerEngines com 20 690 01 Rev Specifications CLEARANCE SPECIFICATIONS SV470 SV530 SV590 SV591 SV471 SV540 SV600 SV601 SV480 SV541 SV610 SV620 Piston Piston Rings and Piston Pin Continued Top and Middle Compression Ring End Gap New Bore Top Ring Middle Ring Used Bore max 0 15 0 40 mm 0 006 0 016 in 0 30 0 55 mm 0 012 0 022 in 0 77 mm 0 030 in Thrust Face O D New Max Wear Limit Spec OOXX Spec 01XX Spec 02XX or higher 83 948 83 962 mm 3 3050 3 3056 in 88 948 88 962 mm 3 5018 3 5024 in 93 928 93 942 mm 3 6980 3 6985 in 88 948 88 962 mm 3 5018 3 502
23. 134 1 6141 in Max Wear Limit 40 964 mm 1 612 in Max Taper 0 012 mm 0 0005 in Max Out of Round 0 025 mm 0 001 in T I R PTO End Crankshaft in Engine m 0 0059 in Entire Crankshaft in V Blocks m0 0039 in Eccentrics O D New 66 940 66 970 mm 2 6354 2 6366 in Max Wear Limit 66 89 mm 2 633 in 3 Values are in Metric units Values in parentheses are English equivalents 20 690 01 Rev KohlerEngines com 9 Specifications CLEARANCE SPECIFICATIONS Cylinder Bore Cylinder Bore I D New Spec OOXX Spec 01XX Spec 02XX or higher Max Wear Limit SV470 SV471 SV480 84 010 84 035 mm 3 307 3 308 in 89 010 89 035 mm 3 504 3 505 in 94 010 94 035 mm 3 701 3 702 in SV530 SV590 SV591 SV540 SV600 SV601 SV541 SV610 SV620 S 94 010 94 035 mm 3 701 3 702 in 89 010 89 035 mm 3 504 3 505 in 94 010 94 035 mm 3 701 3 702 in Spec OOXX 84 073 mm 89 073 mm 3 310 in 3 507 in 89 073 mm 3 507 in 94 073 mm 3 704 in Spec 01XX Spec 02XX or higher Max Taper Max Out of Round Cylinder Head Max Out of Flatness Governor Governor Cross Shaft to Crankcase Running Clearance Cross Shaft O D New Max Wear Limit Governor Gear Shaft to Governor Gear Running Clearance Gear Shaft O D New Max Wear Limit 94 073 mm 3 704 in 0 05 mm 0 002 in 0 12 mm 0 0047 in 0 8 mm 0 003 in 0 013 0 075 mm 0 0005
24. 31 Governor System Governor Sensitivity Adjustment Governor sensitivity is adjusted by repositioning governor spring in holes in governor lever If speed surging occurs with a change in load governor is set too sensitive If a big drop in speed occurs when a normal load is applied governor should be set for greater sensitivity Desired high speed setting RPM will determine governor spring position in governor lever and throttle lever as well as spring used 59 KohlerEngines com 20 690 01 Rev Lubrication System This engine uses a full pressure lubrication system which delivers oil under pressure to crankshaft camshaft connecting rod bearing surfaces and hydraulic valve lifters A high efficiency gerotor oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve limits maximum pressure of system Closure plate must be removed to service oil pickup pressure relief valve and oil pump Lubrication Components EF Oil Fill Dipstick B Oil Filter Oil Drain Plug D Oil Sentry OIL RECOMMENDATIONS CHANGE OIL AND FILTER Refer to Maintenance Change oil while engine is warm CHECK OIL LEVEL 1 Clean area around oil fill cap dipstick Remove drain NOTE To prevent extensive engine wear or damage plug and oil fill cap dipstick Allow oil to drain never run engine with oil level below or above completely operating range indicator on dipstick 2
25. 4 in 93 928 93 942 mm 3 6980 3 6985 in 93 928 93 942 mm 3 6980 3 6985 in 93 828 mm 3 6940 in Spec OOXX 83 828 mm 88 828 mm 3 3003 in 3 4972 in 88 828 mm 3 4972 in 93 828 mm 93 828 mm 3 6940 in 3 6940 in 0 045 mm 0 0018 in Spec 01XX Spec 02XX or higher Piston Thrust Face to Cylinder Bore Running Clearance Valves and Valve Lifters 45 Intake Valve Stem to Valve Guide Running 0 038 0 076 mm 0 0015 0 003 in Clearance Exhaust Valve Stem to Valve Guide Running Clearance Intake Valve Guide D New 6 038 6 058 mm 0 2377 0 2385 in Max Wear Limit 6 135 mm 0 2415 in Intake Valve Stem Diameter New Exhaust Valve Guide I D New Max Wear Limit Exhaust Valve Stem Diameter New 0 0880 mm 0 0035 in 0 050 0 088 mm 0 0020 0 0035 in 5 982 6 0 mm 0 2355 0 2362 in 6 038 6 058 mm 0 2377 0 2385 in 6 160 mm 0 2425 in 5 970 5 988 mm 0 235 0 2357 in Values are in Metric units Values in parentheses are English equivalents Measure 8 mm 0 314 in above bottom of piston skirt at right angles to piston pin 8 Check valve lash every 200 hours adjust as required 20 690 01 Rev KohlerEngines com 11 Specifications GENERAL TOROUE VALUES English Fastener Torgue Recommendations for Standard Applications Bolts Screws Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners O Into Aluminum 9 16 24 3
26. 8 mm 0 0006 0 0011 in Crankcase Governor Cross Shaft Bore I D New 6 025 6 05 mm 0 2372 0 2382 in Max Wear Limit 6 063 mm 0 2387 in Crankshaft End Play free 0 225 1 025 mm 0 0089 0 040 in Bore in Crankcase D New Max Wear Limit Bore in Closure Plate I D New Max Wear Limit Flywheel End Main Bearing Journal O D New Before Serial No 3703200003 New After Serial No 3703200013 O D Max Wear Limit Max Taper Max Out of Round PTO End Main Bearing Journal O D New Before Serial No 3703200003 New After Serial No 3703200013 O D Max Wear Limit Max Taper 41 965 41 990 mm 1 6521 1 6531 in 42 016 mm 1 654 in 44 965 44 990 mm 1 7703 1 7713 in 45 016 mm 1 7723 in 44 913 44 935 mm 1 7682 1 7691 in 44 870 44 895 mm 1 7665 1 7675 in 44 84 mm 1 765 in 0 0220 mm 0 0009 in 0 025 mm 0 001 in 41 913 41 935 mm 1 6501 1 6510 in 41 855 41 880 mm 1 6478 1 6488 in 41 83 mm 1 647 in 0 020 mm 0 0008 in Max Out of Round 0 025 mm 0 001 in Bore in Closure Plate Running Clearance New Before Serial No 3703200003 New After Serial No 3703200013 Bore in Crankcase Running Clearance New Before Serial No 3703200003 New After Serial No 3703200013 Connecting Rod Journal O D 0 030 0 077 mm 0 0012 0 0030 in 0 070 0 120 mm 0 0027 0 0047 in 0 030 0 077 mm 0 0012 0 0030 in 0 085 0 135 mm 0 0033 0 0053 in ew 40 982 41 000 mm 1 6
27. Clean area around oil filter Place a container under filter to catch any oil and remove filter Wipe off mounting surface Reinstall drain plug Torque to 14 0 N m 125 in Ib 3 Place new filter in shallow pan with open end up Fill Ensure engine is cool Clean oil fill dipstick areas of any debris 1 Remove dipstick wipe oil off 2 Reinsert dipstick into tube press completely down with new oil until oil reaches bottom of threads Allow 3 Remove dipstick check oil level Level should be at 2 minutes for oil to be absorbed by filter material top of indicator on dipstick 4 Apply a thin film of clean oil to rubber gasket on new 4 If oil is low on indicator add oil up to top of indicator filter mark 5 Refer to instructions on oil filter for proper 5 Reinstall and secure dipstick installation 6 Fill crankcase with new oil Level should be at top of indicator on dipstick 7 Reinstall oil fill cap dipstick and tighten securely 8 Start engine check for oil leaks Stop engine correct leaks Recheck oil level 9 Dispose of used oil and filter in accordance with local ordinances 20 690 01 Rev KohlerEngines com 23 Lubrication System OIL SENTRY if equipped This switch is designed to prevent engine from starting in a low oil or no oil condition Oil Sentry may not shut down a running engine before damage occurs In some applications this switch may activate a warning signal Read your equipment m
28. Crank Battery is discharged Faulty electric starter or solenoid Faulty key switch or ignition switch Interlock switch is engaged or faulty Loose wires or connections that intermittently ground ignition kill circuit Pawls not engaging in drive cup Seized internal engine components Engine Runs But Misses Carburetor adjusted incorrectly Engine overheated Faulty spark plug s Ignition module s faulty or improperly gapped Incorrect crankshaft position sensor air gap Interlock switch is engaged or faulty Loose wires or connections that intermittently ground ignition kill circuit Quality of fuel dirt water stale mixture Spark plug lead s disconnected Spark plug lead boot loose on plug Spark plug lead loose Engine Will Not Idle Engine overheated Faulty spark plug s Idle fuel adjusting needle s improperly set Idle speed adjusting screw improperly set Inadequate fuel supply Low compression Quality of fuel dirt water stale mixture Restricted fuel tank cap vent Engine Overheats Cooling fan broken Excessive engine load Fan belt failed off Faulty carburetor High crankcase oil level Lean fuel mixture Low cooling system fluid level Low crankcase oil level Radiator and or cooling system components clogged restricted or leaking Water pump belt failed broken Water pump malfunction Engine Knocks Excessive engine load Hydraulic lifter malfunction Incor
29. ER 2505 2487 X 1 25 2 STUDS 24 141 70 120 00 4 724 Ps 2 519 3 161 249 93 9 840 TO EXHAUST PORT ENGINE MOUNT ING SURF ACE 7 16 y 38 ACCESSORY MOUNT ING LOCAT ION 20 UNF 2B IN l STARTER VIEW m 35 72 1 408 60 SPEED CONTROL LEVER TRAVEL Specifications Dimensions in millimeters Inch equivalents shown in 221 91 8 737 207 25 8 159 TO OIL FILTER 174 21 120 00 6 859 4 724 EVEL ICK PUO VDC CAE THROTTLE CABLE CLIP 310 353 72 13 926 sy y 12 230 LIFTING POINT EXHAUST FLANGE MOUNTING SURFACE CORED FOR M 6 SELF TAPPING SCREW 7 V 15 ACCESSORY MOUNT ING LOC CHOKE ENGAGEMENT START a 17 00 1 184 669 14 TO CARBURETOR CHOKE SHUTDOWN SOLENOID LEVER OPTIONAL TRAVEL OIL FILTER VIEW 20 690 01 Rev O IL D 8 N P U IN PLUG Te INCH ENGINE MOUNTING SURFACE THROTTLE CABLE CLIP 327 81 13 00 OIL FILTER REMOVAL 12 906 512 108 68 22922 109 55 8 906 7 821 4 313 LIFTING TO OIL POINT FILTER OIL FILTER D MM MIN OCAT ION 279 45 11 002 FLYWHEEL VIEW Ube Po a 134 00 5 276 al a
30. Gi KohlerEngines com 254 00 10 000 PTO VIEW 9 63 LIFI 379 PO ROTATION Specifications ENGINE IDENTIFICATION NUMBERS Kohler engine identification numbers model specification and serial should be referenced for efficient repair ordering correct parts and engine replacement Courage Engine Vertical Shaft Numerical Designation Specification SV470 0001 i E Year Manufactured Code Factory Code Year 2012 43 2013 44 2014 GENERAL SPECIFICATIONS SV470 SV530 SV590 SV591 SV471 SV540 SV600 SV601 SV480 SV541 SV610 SV620 94 mm 3 70 in Spec OOXX 84 mm 3 30 in 89 mm 3 50 in Spec 01XX 89 mm 3 50 in Spec 02XX or higher 94 mm 3 70 in 94 mm 3 70 in Stroke 86 mm 3 38 in Displacement a 597 cc 36 4 cu in Spec OOXX 477 cc 29 1 cu in 535 cc 32 6 cu in Spec 01XX 535 cc 32 6 cu in Spec 02XX or higher 597 cc 36 4 cu in 597 cc 36 4 cu in Sa Oil Capacity refill 1 5 L 1 6 U S qt Maximum Angle of Operation full oil level 25 TORQUE SPECIFICATIONS SV470 SV530 SV590 SV591 SV471 SV540 SV600 SV601 SV480 SV541 SV610 SV620 Air Cleaner Base Hex Nut Fastener 5 5 N m 48 in Ib Mounting Screw Fastener install dry 8 0 N m 70 in lb into new hole 5 5 N m 48 in Ib into used hole Balance Weight 10 9 13 2 Nem 95 0 115 0 in lb Blower Housing and Sheet Me
31. Ib Flywheel M12 Retaining Screw 88 0 N m 65 ft Ib M10 Retaining Screw 66 5 N m 49 ft lb Governor 7 0 8 5 Nim 6075 in Ib Ignition Spark Plug 27 N m 20 ft Ib Module Fastener 6 0 N m 55 in Ib into new hole 4 0 N m 35 in Ib into used hole Rectifier Regulator Fastener 6 0 N m 55 in Ib into new hole 4 0 N m 35 in Ib into used hole Muffler Retaining Nuts 24 4 N m 216 in Ib Oil Filter Pad Pipe Plug 1 8 N P T F 4 5 5 0 N m 40 46 in Ib Oil Pump Mounting Screw 0 7 5 N m 44 4 66 0 in Ib into new hole 8 4 6 N m 33 3 40 3 in Ib into used hole gt Values are in Metric units Values in parentheses are English equivalents gt Lubricate threads with engine oil prior to assembly 20 690 01 Rev KohlerEngines com 7 Specifications TORQUE SPECIFICATIONS SV470 SV530 SV590 SV591 SV471 SV540 SV600 SV601 SV480 SV541 SV610 SV620 Oil Sentry Pressure Switch 4 5 5 0 N m 40 45 in Ib Speed Control Bracket Assembly Fastener 11 0 N m 95 in Ib into new hole 7 5 N m 65 in Ib into used hole Stator Mounting Screw m 55 in Ib into new hole m 35 in Ib into used hole Valve Cover Fastener 11 0 N m 95 in Ib into new hole 7 5 N m 65 in Ib into used hole CLEARANCE SPECIFICATIONS SV470 SV530 SV590 SV591 SV471 SV540 SV600 SV601 SV480 SV541 SV610 SV620 Balance Weight Bearing Surface I D New 67 011 67 086 mm 2 6382 2 6412 in Max Wear Li
32. If side clearance is greater than specified a new piston must be used Install Piston Rings NOTE Rings must be installed correctly Ring installation instructions are usually included with new ring sets Follow instructions carefully Use a piston ring expander to install rings Install bottom oil control ring first and top compression ring last KohlerEngines com 99 Disassembly Inspection and Service To install piston rings proceed as follows 1 Oil control ring bottom groove Install expander and then rails Make sure ends of expander are not overlapped 2 Compression ring center groove Install center ring using a piston ring installation tool Make sure identification mark is up when ring is installed 3 Compression ring top groove Install top ring using a piston ring installation tool Make sure identification mark is up when ring is installed Remove Crankshaft and Balance Weight Assembly Carefully remove crankshaft and balance weight assembly from crankcase On engines with Second Generation Balance Weight carefully lift lower control link for balance weight off boss of crankcase as crankshaft is removed Models with Third Generation Balance Weight have a balance weight guidance shaft and link which can be removed before removing crankshaft and balance weight assembly Crankshaft and Crank Gear Inspection and Service Inspect teeth of crank gear If teeth are badly worn chipped or some are missin
33. KOHLER Courage SV470 SV620 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 2 Safety 3 Maintenance 5 Specifications 13 Tools and Aids 16 Troubleshooting 20 Air Cleaner Intake 21 Fuel System 31 Governor System 33 Lubrication System 35 Electrical System 44 Starter System 47 Emission Compliant Systems 50 Disassembly Inspection and Service 63 Reassembly 20 690 01 Rev KohlerEngines com Safety SAFETY PRECAUTIONS AA WARNING A hazard that could result in death serious injury or substantial property damage AA 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 d WARNING A WARNING CAUTION Explosive Fuel can cause Accidental Starts can Electrical Shock can cause injury Do not touch wires while fires and severe burns cause severe injury or Do not fill fuel tank while death engine is running engine is hot or running Disconnect and ground Gasoline is extremely flammable spark plug lead s before and its vapors can explode if Servicing ignited Store gasoline only in l approved containers in well Before working on engine or ventilated unoccupied buildings equipm
34. Make sure lights are not burned out across battery terminals using a DC voltmeter Condition Conclusion Condition E Burned out lights Voltage is more than 12 5 Charging system is OK volts Voltage is 12 5 volts or Saro diode ac 2 Disconnect lighting lead from wiring harness less probably faulty Continue With engine running in fast setting measure voltage testing stator and diode from lighting lead to ground using an AC voltmeter Condition Conclusion 2 Remove connector from rectifier regulator With engine running in fast position measure AC voltage la is 15 volts or GH across stator leads using an AC voltmeter Shorts in wiring harness Condition Conclusion K is less than 13 Test stator i an Voltage is 20 volts or Stator winding is OK Panda EA more Voltage is less than 20 Test stator using an 3 With engine stopped measure resistance of stator volts ohmmeter from lighting lead to ground using an ohmmeter Condition Conclusion 3 With charging lead disconnected from battery and Resistance is Stator is OK engine stopped measure resistance from charging a AAA lead to ground using an ohmmeter Note reading approximately 0 2 ohms Reverse leads and measure resistance again Resistance is 0 ohms Stator is shorted Replace stator In one direction resistance should be infinity ohms SE open circuit With leads reversed some resistance Resistance is infinity Stator or ligh
35. Pivot exhaust cam lever toward push rod bore then insert cam shaft into counterbore of crankcase Make sure pin stays in groove of thrust washer 3 Lubricate cam surfaces of cam gears with light grease or oil 4 Assemble and install ACR automatic compression release into exhaust cam gear if removed for servicing a Install spring onto ACR weight with loop around post and formed upper leg hooked behind upper section b Install ACR assembly into hole of exhaust cam gear and hook long leg behind notched tab 5 Lift exhaust cam lever and install exhaust cam gear with assembled ACR onto cam shaft engaging slot with upper drive pin Rotate gear and shaft so EX timing mark on cam gear is in 8 o clock position Install thrust washer onto cam shaft Install Intake Cam on Cam Shaft NOTE Cam gear assemblies may contain either two or four rivets Lift intake cam lever and install intake cam gear onto intake cam shaft engaging slot with upper drive pin Rotate gear and shaft so IN timing mark on cam gear is in 4 oclock position Early models only install thrust washer if used originally onto cam shaft Install Crank Gear Orient crankshaft so key is in 12 o clock position Hold crank gear with timing marks visible and slide it onto crankshaft and key so timing marks on crank gear align with timing marks on cam gears 20 690 01 Rev Reassembly Install Flywheel Side Oil Seal NOTE A special gasket used between c
36. Sealant or equivalent to 1 8 pipe plug or 90 fitting as equipped Install and tighten into tapped vacuum port of closure plate Torque plug to 4 5 5 0 N m 40 45 in Ib Turn outlet of a fitting to 8 o clock position 2 Ifa fitting is used connect fuel pump pulse line and secure with clamp If fuel pump is attached to air cleaner base do not connect pulse line at this time Install Fan and Flywheel caution Damaging Crankshaft and Flywheel can cause personal injury Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions and procedures when installing flywheel NOTE Before installing flywheel make sure crankshaft taper and flywheel hub are clean dry and completely free of lubricants Presence of lubricants can cause flywheel to be over stressed and damaged when mounting screw is torqued to specification NOTE Make sure flywheel key is installed properly in keyway Flywheel can become cracked or damaged if key is not properly installed NOTE Always use a flywheel strap wrench or flywheel holding tool to hold flywheel when tightening flywheel fastener Do not use any type of bar or wedge between cooling fins or flywheel ring gear as these parts could become cracked or damaged 1 Install appropriate key into crankshaft keyway Based on crankshaft keyway style use either a woodruff or straight key Make sure key is fully sea
37. Valve Inspection and Service Outlet Seal Styles Some Models Open Outlet Seal B Closed Outlet Seal 20 690 01 Rev Disassembly Inspection and Service Closure plate must be removed to inspect and service oil pump Check oil pump and gears for cracks damage wear and smooth rotation Replace pump if any binding is noted or reuse is questionable in any way A pressure relief valve is built into oil pump to limit maximum pressure lt is not serviceable If a problem exists with pressure relief valve oil pump assembly should be replaced Automatic Compression Release ACR These engines are equipped with an ACR mechanism ACR lowers compression at cranking speeds to make starting easier Operation ACR mechanism consists of an actuating spring and a pivoting flyweight control pin assembly located in exhaust side cam gear A thrust washer and mounting closure plate hold ACR in position At cranking speeds 700 RPM or lower spring holds flyweight in and rounded surface of control pin protrudes above exhaust cam lobe This pushes exhaust valve off its seat during first part of compression stroke Compression is reduced to an effective ratio of about 2 1 during cranking After starting when engine speed exceeds 700 RPM centrifugal force overcomes force of the flyweight spring Flyweight moves outward rotating control pin to expose the flat surface which is lower than cam lobe Control pin no longer has any effect on ex
38. a 6 35 mm 1 4 in drill bit to hold in position Current Models Current models use a new control assembly identified by three alignment holes close to throttle lever pivot Based upon intended high speed RPM setting throttle cable adjustment must be made by matching hole in control lever with correct alignment hole Use appropriate hole for corresponding high speed settings Move throttle lever to align hole in lever with correct hole in control bracket Insert a pencil or a 6 35 mm 1 4 in drill bit to hold in position Pull on outer shield of throttle control cable to remove any slack Tighten cable clamp securely Move application throttle lever to slow position then to full throttle Check engine control to ensure it stops against stop screw which means it is properly set Choke Control Installation 1 2 3 30 Connect choke cable boden wire to engine choke control lever on speed control bracket assembly Position choke cable under cable clamp Push move choke control to off position in application panel until it bottoms then pull it back approximately 1 16 in Push on choke cable ahead of clamp on engine control plate until choke lever stops Do not force Then tighten cable clamp screw Move choke control until it stops on position Check that choke link cannot be moved towards carburetor by applying finger pressure on lower link lever below engine control plate If choke link moves readjust
39. a R Rocker Arm Stud Push Rod Guide Plate Remove Valve Cover 2 Remove screws securing cylinder head Note thick q 2 lt _ _z gt E _ washer used on screw closest to exhaust port Valve Cover with Gasket 1 Remove screws securing valve cover and any 3 Remove cylinder head and head gasket attached brackets 4 Remove drain back check ball some models from keyhole slot in crankcase Models without a check i REONE VANE Covel ANN JARKE MOME NAE NICAN ball have an internal drain back tube in crankcase Valve Cover with RTV Sealant NOTE Valve cover is sealed to cylinder head using Disassemble Cylinder Head RTV silicone sealant When removing valve cover use care not to damage gasket surfaces Cylinder Head Spark Plug NOTE Before disassembly mark all valve train of cover and cylinder head To break RTV seal components that will be reused to assure they hold a block of wood against 1 flat face of valve are reassembled on same side cover Strike wood firmly with a mallet If seal 1 Remove spark plug doesn t break loose after 1 or 2 attempts repeat 2 Remove adjustment nuts pivots and rocker arms procedure on other side from pivot studs 1 Remove screws securing valve cover and any 3 Remove rocker arm pivot studs and push rod guide attached brackets plates 2 Using a brass wire brush and gasket remover or similar solvent clean old RTV from surface of oe oo l l l cylinder head
40. a tachometer Setting Low Idle RPM 1 2 Move application control to slow position Using a tachometer check RPM Then using a screwdriver turn low idle speed screw inward clockwise to increase RPM and outward counterclockwise to lower RPM 20 690 01 Rev Governor System GOVERNOR 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 Most engines are eguipped with a centrifugal flyweight mechanical governor Governor gear flyweight mechanism of mechanical governor is mounted inside closure plate and is driven off gear on crankshaft Governor Components Inside Engine Governor Cross Shaft Speed Control Bracket Throttle Lever Throttle Linkage F A e Choke Linkage D Governor Spring NN Fuel Pump Fuel Pump Bracket Flyweight Regulating Pin M Governor Gear This governor design works as follows e Centrifugal force acting on rotating governor gear assembly causes flyweights to move outward as speed increases Governor spring tension moves Governor Adjustments NOTE Do not tamper with governor setting Overspeed is hazardous and could cause personal injury them inward as speed decreases Initial Adjustment Procedure e As flyweights move outward they cause regulating pin Make this adjustment whenever governor arm is to move out
41. anuals for more information Oil Sentry pressure switch is installed into center oil galley of filter adapter casting or into closure plate Based on application an elbow adapter may also be used On engines not equipped with Oil Sentry oil galley is sealed with a 1 8 pipe plug or completely sealed Installation External Switch 1 Remove and discard pipe plug from center passage of oil filter mounting pad 2 Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads of 90 adapter if used and Oil Sentry switch Install adapter if used and carefully tighten it to intended position Do not over tighten or damage adapter 3 Install switch into adapter or center passage Torque switch to 4 5 5 0 N m 40 45 in lb Connect lead to terminal on Oil Sentry switch Switch Behind Blower Housing Remove blower housing Remove and discard pipe plug from closure plate 2 Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads of Oil Sentry switch 3 Install switch into closure plate Torque switch to 4 5 5 0 N m 40 45 in Ib Connect lead to terminal on Oil Sentry switch 4 Reinstall blower housing Testing Compressed air a pressure regulator pressure gauge and a continuity tester are required to test switch 1 Connect continuity tester across blade terminal and metal case of switch With O psi pressure applied to sw
42. arburetor spacer Curved section of heat deflector should be down toward engine If deflector contains a molded protruding point it should be towards back inserted into intake port Be sure protruding point goes through large hole in gasket to keep it aligned 4 Models with one screw and one mounting stud only Insert a 3 16 diameter rod approximately 4 long into open mounting hole in heat deflector carburetor spacer to serve as a temporary alignment pin Be careful not to force rod or damage threads 5 Install heat shield if equipped with gasket or a new carburetor gasket onto mounting stud s and or alignment pin 6 Attach choke and throttle linkages to carburetor and install carburetor assembly If governor lever was not disconnected slide it onto governor shaft with lever up 7 W carburetor has a fuel solenoid fasten ground lead to crankcase boss with toothed washer between eyelet terminal and boss Torque screw to 8 0 N m 70 in Ib Connect solenoid power lead to wiring harness and secure with a tie strap 8 Connect fuel line to carburetor and secure with a hose clamp 9 Install air cleaner base with fuel pump attached if equipped a Install a new air cleaner base gasket Check two metal spacers are in air cleaner base mounting holes and install base onto stud s and or alignment pin Make sure upper mounting tab is positioned above closure plate boss Install nut s and finger tighten b Model
43. ation Both styles of outlet seals are shown If a new seal is to be ordered be sure it is same style as what was removed Lightly lubricate ends of oil pump outlet seal with oil and install in into outlet of oil pump 20 690 01 Rev 20 690 01 Rev Install intake cam shaft down into crankcase boss Seat rubber oil pump outlet seal into machined pocket If an open style outlet seal is used check to make sure small feed hole is open and aligned with lower main bearing oil feed hole Use a 3 32 allen wrench or a light with a mirror Push steel sleeves in pump housing down until bottomed against mounting surface Install two M5 mounting screws Hold pump outlet against main bearing area and torque screws to 6 2 N m 55 in Ib into new holes or 4 0 N m 35 in Ib into used holes If engine uses a drain back tube insert round flanged end into hole near base of cylinder and clip it onto oil pump body Install Crankshaft and Balance Weight NOTE If installing a crankshaft with third generation balance weight steps 1 and 2 do not need to be performed Assemble crankshaft balance weight if removed from crankshaft a Lubricate crankshaft eccentrics and balance weight bearing surfaces with oil b Install two balance weight halves onto crankshaft eccentrics as marked or originally installed c First generation balance weight assembly Align weights and install balance weight screw through mounting holes from PTO si
44. ble If guides are within limits but valve stems are worn beyond limits replace valves Valve Seat Inserts Hardened steel alloy intake and exhaust valve seat inserts are press fitted into cylinder head Inserts are not replaceable but they can be reconditioned if not too badly pitted or distorted If seats are cracked or badly warped cylinder head should be replaced Recondition valve seat inserts following instructions provided with valve seat cutter being used Final cut should be made with an 89 cutter as specified for valve seat angle With proper 45 valve face angle and valve seat cut properly 44 5 as measured from center line when cut 89 this would result in desired 0 5 1 0 full cut interference angle where maximum pressure occurs on valve face and seat Lapping Valves Reground or new valves must be lapped in to provide a good seal Use a hand valve grinder with suction cup for final lapping Lightly coat valve face with fine grade of grinding compound then rotate valve on seat with grinder Continue grinding until smooth surface is obtained on seat and on valve face Thoroughly clean cylinder head in soap and hot water to remove all traces of grinding compound After drying cylinder head apply a light coating of engine oil to prevent rusting 20 690 01 Rev Disassembly Inspection and Service Cam Closure Plate Components Ly d Z vill DCH bk ag Sa Take AT osa B Closure
45. d Control Bracket Alignment Hole Throttle Cable Clamp Choke Cable Clamp Early Models Later Models E Current Models F Alignment Hole Alignment Hole for Alignment Hole for 3000 RPM and Higher Less Than 3000 RPM Alignment Hole for J Alignment Hole for 3101 3750 RPM 2901 3100 RPM Alignment Hole for 2400 2900 RPM KohlerEngines com 29 Fuel System Throttle Control Installation 1 2 Loosen two cable clamp screws on speed control bracket assembly Move application throttle control lever to maximum full fast throttle position and then move it back 3 16 or 4 75 mm Insert cable boden wire into throttle control lever on control plate Position throttle cable under cable clamp Early Models Early models use a single alignment hole to set engine RPM Align hole in throttle lever with hole in speed control bracket by inserting a pencil or 6 35 mm 1 4 in drill bit Later Models Later models utilize a new design control assembly identified by two opposing alignment holes close to throttle lever pivot instead of one Based upon intended high speed RPM setting throttle cable adjustment must be made matching hole in control lever with appropriate alignment hole Use lower left side hole for high speed settings 3000 RPM and above Use upper right side hole for high speed settings less than 3000 RPM Move throttle lever to align hole in lever with appropriate hole in control bracket Insert a pencil or
46. d brushes Individual component available Starter Brush Holding Tool Solenoid Shift SE Tools KLR 82416 Triad OHC Timing Tool Set Kohler 28 761 01 S For holding cam gears and crankshaft in timed position while installing timing belt Valve Guide Reamer K and M Series Design Technology Inc For properly sizing valve guides after installation DTI K828 Valve Guide Reamer O S Command Series Kohler 25 455 12 S For reaming worn valve guides to accept replacement oversize valves Can be used in low speed drill press or with handle below for hand reaming Reamer Handle Design Technology Inc For hand reaming using Kohler 25 455 12 S reamer DTI K830 Valve Guide Service Kit Courage Aegis Command OHC SE Tools KLR 82415 For servicing worn valve guides AIDS Description Source Part No RTV Silicone Sealant Loctite 5900 Heavy Body in 4 oz aerosol dispenser Kohler 25 597 07 S Only oxime based oil resistant RTV sealants such as those listed are approved Loctite 5910 for use Loctite Nos 5900 or 59109 are recommended for best sealing Loctite Ultra Black 598 M characteristics Loctite Ultra Blue 587 Loctite Ultra Copper 5920 Spline Drive Lubricant Kohler 25 357 12 S 14 KohlerEngines com 20 690 01 Rev FLYWHEEL HOLDING TOOL A flywheel holding tool can be made out of an old junk flywheel ring gear and used in place of a strap wrench 1 Using an abrasive cut off wheel cut out a six tooth segmen
47. d high speed no load RPM Governed idle speed must be set before making this adjustment Low Idle Fuel Adjustment Optimum Low Idle Fuel Setting A Midpoint D Left Side E Right Side NOTE Engines will have fixed low idle or limiter caps on idle fuel adjusting needles Step 2 can only be performed within limits allowed by cap Do not attempt to remove limiter caps KohlerEngines com 25 Fuel System 1 Place throttle control into idle or slow position Adjust low idle speed to 1200 RPM Follow Low Idle Speed RPM Adjustment 2 Low idle fuel needle s setting place throttle into idle or slow position a Turn 1 low idle fuel adjusting needle out counterclockwise from preliminary setting until engine speed decreases rich Note position of needle Now turn adjusting needle in clockwise Engine speed may increase then it will decrease as needle is turned in lean Note position of needle Set adjusting needle midway between rich and lean settings b Repeat procedure on other low idle adjustment needle two barrel carburetor only 3 Recheck adjust Low Idle Speed RPM to specified setting High Speed RPM Adjustment 1 With engine running move throttle control to fast 2 Turn inner adjustment screw outward to decrease or inward to increase RPM speed Courage singles require loosening screws on speed control bracket and sliding towards carburetor to lower and away from carburetor to increase speed
48. d out lights less probably faulty Continue testing stator and diode 2 Disconnect lighting lead yellow from wiring harness 2 Remove connector from rectifier regulator With With engine running in fast setting measure voltage engine running in fast position measure AC voltage from lighting lead to ground using an AC voltmeter across stator leads using an AC voltmeter Condition Conclusion Voltage is 13 volts or Stator is OK Check for more loose connections or shorts in wiring harness Condition Conclusion Voltage is 5 volts or more Stator winding is OK Voltage is less than 5 Test stator using an volts ohmmeter Voltage is less than 13 Test stator using an volts ohmmeter 3 With engine stopped measure resistance of stator from lighting lead to ground using an ohmmeter 3 With charging lead disconnected from battery and engine stopped measure resistance from charging lead to ground using an ohmmeter Note reading Reverse leads and measure resistance again a l T Condition Conclusion In one direction resistance should be infinity ohms r r F open circuit With leads reversed some resistance Stator is OK should be measured about midscale on Rx1 range approximately 0 15 ohms Resistance is 0 ohms Stator is shorted Replace Condition Conclusion stator Resistance is low in both Diode is shorted Replace directions diode Resistance is infinity Stator or lighting lead is ohms o
49. d power governor Low idle fuel mixture is improperly Adjust low idle fuel needle hunting or excessive throttle adjusted Opening Dirt under fuel inlet needle Remove needle clean needle and seat and blow with compressed air Bowl vent or air bleeds plugged Remove fuel bowl low idle fuel adjusting needle and welch plugs Clean vent ports and air bleeds Blow out all passages with compressed air Fuel bowl gasket leaks Remove fuel bowl and replace gasket Leaky cracked or damaged float Submerge float to check for leaks Engine runs lean indicated by Low idle fuel mixture is improperly Adjust low idle fuel needle misfiring loss of speed and power adjusted governor hunting or excessive Idle holes plugged dirt in fuel delivery Remove fuel bowl low idle fuel throttle opening channels adjusting needle and welch plugs Clean main fuel jet and all passages blow out with compressed air Fuel leaks from carburetor Dirt under fuel inlet needle Remove fuel bowl low idle fuel adjusting needle and welch plugs Clean vent ports and air bleeds Blow out all passages with compressed air Float is cracked or damaged Replace float Bowl retaining screw gasket Replace gasket damaged Bowl retaining screw loose Torque screw to specifications Walbro 5 1 6 2 N m 45 55 in Ib or Nikki 10 8 12 8 N m 96 113 in Ib 24 KohlerEngines com 20 690 01 Rev FUEL SYSTEM Fuel Shut off Solenoid Most carb
50. de Thread it into guide pin outside weight on flywheel side Hold guide pin with a wrench or Torx bit and torgue screw to 11 3 N m 100 in Ib Do not hold or damage outside diameter O D of guide pin Second generation balance weight assembly Align weights and insert balance weight screw through mounting holes from flywheel side Thread it into guide pin outside weight on PTO side Hold guide pin with a wrench or Torx bit and torque screw to 11 3 N m 100 in Ib Do not hold or damage outside diameter O D of guide pin Apply grease to inner diameter 1 D of each hole in control link and install one end over guide pin Carefully install crank gear key in keyway First generation balance weight assembly Carefully install crankshaft into crankcase through PTO seal and seat fully into place Rotate crankshaft so journal for connecting rod is away from cylinder Second generation balance weight assembly Make sure pivot pin on boss in lower section of crankcase is clean and free of any nicks or surface irregularities Apply a small amount of grease to O D Third generation balance weight assembly Carefully install crankshaft into crankcase through PTO seal and seat fully into place 4 Reassembly First generation balance weight assembly Install balance weight guide shoe onto guide pin with solid end toward crankshaft Second generation balance weight assembly Apply a small amount of grease to O D of gui
51. de pin on PTO side of counterweight and install control link Carefully install crankshaft with link hold in position as reguired through PTO seal Slightly rotate counterweight assembly and guide outer end of link over stationary guide pin in crankcase Seat link and crankshaft fully into place do not force either part into position Third generation balance weight assembly Apply a small amount of engine oil to ends of guidance shaft Install guidance shaft through links into boss of crankcase Install Piston Rings NOTE For detailed piston inspection procedures and piston ring installation refer to Disassembly Inspection and Reconditioning Install Piston to Connecting Rod Assemble piston connecting rod piston pin and piston pin retainers Install Piston and Connecting Rod NOTE Proper orientation of piston connecting rod inside engine is extremely important Improper orientation can cause extensive wear or damage Stagger piston rings in grooves until end gaps are 120 apart Lubricate cylinder bore crankshaft journal connecting rod journal piston and rings with engine oil Compress piston rings using a piston ring compressor Orient FLY mark on piston toward flywheel side of crankcase Place ring compressor on top surface of crankcase and make certain it is seated down around entire circumference Use a soft rubber grip hammer handle and tap piston connecting rod into bore First tap should be rather fir
52. debris on crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas can cause overheating e Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or inoperative breather worn or damaged seals or gaskets or loose fasteners e Check air cleaner cover and base for damage or indications of improper fit and seal e Check air cleaner element Look for holes tears cracked or damaged sealing surfaces or other damage that could allow unfiltered air into engine A dirty or clogged element could indicate insufficient or improper maintenance e Check carburetor throat for dirt Dirt in throat is further indication that air cleaner was not functioning properly e Check if oil level is within operating range on dipstick If it is above sniff for gasoline odor e Check condition of oil Drain oil into a container it should flow freely Check for metal chips and other foreign particles Sludge is a natural by product of combustion a small accumulation is normal Excessive sludge formation could indicate over rich fuel settings weak ignition overextended oil change interval or wrong weight or type of oil was used CLEANING ENGINE Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and
53. el Ignition Module Optional Oil Sentry 20 690 01 Rev KohlerEngines com 4 Electrical System 9 15 Amp Regulated Battery Charging System NOTE Zero ohmmeter on each scale before testing to ensure accurate readings Voltage tests should be made with engine running at full throttle with no load Battery must be fully charged To test charging system for no charge to battery 1 Insert an ammeter in B lead from rectifier regulator With engine running at 3600 RPM and B at terminal on rectifier regulator to ground using a DC voltmeter If voltage is 13 8 volts or more place a minimum load of 5 amps turn on lights if 60 watts or more or place a 2 5 ohm 100 watt resistor across battery terminals on battery to reduce voltage Observe ammeter Condition Conclusion Charge rate increases when load is applied Charging system is OK and battery was fully charged Test stator and rectifier Charge rate does not regulator steps 2 and 3 increase when load is applied 2 Remove connector from rectifier regulator With engine running at 3600 RPM measure AC voltage across stator leads using an AC voltmeter Condition Conclusion Voltage is 28 volts or Stator is OK Rectifier more regulator is faulty replace Voltage is less than 28 Stator is faulty replace volts Test stator further using an ohmmeter steps 3 and 4 3 With engine stopped measure resistance across stator leads using an onmmet
54. ent disable engine as away from sparks or flames follows 1 Disconnect spark plug Spilled fuel could ignite if it comes lead s 2 Disconnect negative in contact with hot parts or sparks battery cable from battery from ignition Never use gasoline as a cleaning agent A WARNING Hot Parts can cause A WARNING zh severe burns And Rotating Parts can cause me DO not touch engine severe injury while operating or just Stay away while engine after stopping Is in operation Never operate engine with heat Keep hands feet hair and shields or guards removed clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed Cleaning Solvents can cause severe injury or gege WARNING Use only in well Carbon Monoxide can ventilated areas away cause severe nausea from ignition sources tainting eat Carburetor cleaners and solvents Avoid inhaling exhaust are extremely flammable Follow fumes cleaner manufacturer s warnings Engine exhaust gases contain and instructions on its proper and poisonous carbon monoxide safe use Never use gasoline as a Carbon monoxide is odorless cleaning agent colorless and can cause death if inhaled amp caon Damaging Crankshaft and Flywheel can cause Jo personal injury OS Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions a
55. er Condition Conclusion Resistance is 0 1 0 2 Stator is OK ohms Resistance is infinity Stator is open replace ohms 4 With engine stopped measure resistance from each stator lead to ground using an ohmmeter Condition Conclusion Geer is infinity ohms Stator is OK not shorted no continuity to ground Stator leads are shorted to ground replace To test charging system for battery continuously charging at high rate 1 With engine running at 3600 RPM measure voltage from B lead to ground using a DC voltmeter Resistance or continuity measured 42 KohlerEngines com Condition Conclusion Voltage is 14 7 volts or Charging system is OK less Battery is unable to hold charge service or replace Voltage is more than 14 7 Faulty rectifier regulator volts replace BLADE STOP STATOR BRAKE CIRCUIT Wiring Diagram Blade Stop Stator Brake Circuit DNR e mn Ip E Engine LE e Be Mow Module ENE ER K CDI Ignition OEM uge J on E m see n Sen ol Key Switch Blade stop stator brake circuit is provided as a safety feature to ensure application can meet ANSI American National Standards Institute application blade stop requirements Circuit is activated if operator gets off of seat of application while mower blade system is activated or in certain reverse mow conditions Circuit is activated by taking ignition shutdown kill lead to ground This action turn
56. er a Walbro or 3 Make sure fuel is reaching carburetor This includes Nikki fixed main jet carburetor Carburetors will have a checking fuel shut off valve fuel tank filter screen low idle speed adjustment screw and either fixed idle or in line fuel filter fuel lines and fuel pump for a limiter cap on idle fuel adjustment needle restrictions or faulty components as necessary 4 Make sure air cleaner base and carburetor are e securely fastened to engine using gaskets in good When engine starts hard runs rough or stalls at low condition k eet rage oe areas before adjusting or 5 Make sure air cleaner element including precleaner PS if eguipped is clean and all air cleaner components 1 Make sure fuel tank is filled with clean fresh are fastened securely gasoline 6 Make sure ignition system governor system 2 Make sure fuel tank cap vent is not blocked and is exhaust system and throttle and choke controls are operating properly operating properly Troubleshooting Carburetor Related Causes Condition Possible Cause Conclusion Engine starts hard runs rough or Low idle fuel mixture speed Adjust low idle speed screw then stalls at idle speed improperly adjusted adjust low idle fuel needle Improper choke adjustment Correct choke adjustment Engine runs rich indicated by black Choke partially closed during Check choke lever linkage to ensure sooty exhaust misfiring loss operation choke is operating properly of speed an
57. er motor NOTE If engine develops sufficient speed to disengage starter but does not keep running a false start engine rotation must be allowed to come to a complete stop before attempting to restart engine If starter is engaged while flywheel is rotating starter pinion and flywheel ring gear may clash and damage starter NOTE If starter does not crank engine shut off starter immediately Do not make further attempts to start engine until condition is corrected NOTE Do not drop starter or strike starter frame Doing so can damage starter Engines in this series use inertia drive starters Troubleshooting Starting Difficulties Condition Possible Cause Conclusion Starter does not energize Battery Check specific gravity of battery If low recharge or replace battery as necessary Wiring Clean corroded connections and tighten loose connections Replace wires in poor condition and with frayed or broken insulation Starter Switch By pass switch or solenoid with a jumper wire If starter cranks or Solenoid normally replace faulty components Starter energizes but turns Battery Check specific gravity of battery If low recharge or replace slowly battery as necessary Battery too small must be at least 250 cold cranking amps Brushes Check for excessively dirty or worn brushes and commutator Clean using a coarse cloth not emery cloth Replace brushes if excessively or unevenly worn Transmission Make sure clutch or transmission
58. erRegulator G Electric Starter H OllFiter DU FuelFiter J Oi Senty K Ar Cleaner Cover L Precleaner M AirCleaner Element N AirCleanerBase O Gasket P Carburetor o R s w w Vi Oil Drain Plug Nikki Fuel Solenoid Walbro Fuel Solenoid Heat Deflector Heat Shield Carburetor Spacer CD 0 KohlerEngines com 20 690 01 Rev 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 guickly remove grease oil and grime from engine parts When such a cleaner is used follow manufacturer s instructions and safety precautions carefully Make sure all traces of cleaner are removed before engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down lubricating properties of engine oil Drain Oil from Crankcase and Remove Oil Filter 1 Remove oil drain plug and oil fill cap dipstick 2 Allow ample time for oil to drain from crankcase 3 Remove and discard oil filter Remove Blower Housing 1 Remove screws securing blower housing to closure plate 2 Lift blower housing and separate spark plug lead from corresponding slot Remove Oil Sentry Pressure Switch if equipped NOTE Pressure switch is installed into center oil galley of filter adapter casting or into closure plate 1 Disconnect lead from Oil Sentry pressure s
59. erve tester Visible and audible sparks should be produced Condition Possible Cause Conclusion See visible sparks are Ignition Module Ignition module is OK Audible and visible sparks are not Ignition Module or Electrical System Make sure engine ignition switch produced kill switch or key switch is in RUN position Check wires and terminals of ignition module and other components for accidental grounding and damaged insulation If wires and terminals are OK ignition module is probably faulty and should be replaced Test module further using an ohmmeter Test Ignition Module with Ohmmeter NOTE This test cannot be performed unless module has been fired at least once Measure resistance of module secondary using an ohmmeter 1 Zero ohmmeter 2 Connect one ohmmeter lead to laminations Connect other lead to spark plug terminal of high tension lead 3 With ohmmeter leads connected in this manner resistance of secondary should be 7 900 to 18 400 ohms Refer to Disassembly and Reassembly for complete ignition module removal and installation procedures Condition Possible Cause Conclusion Resistance is within specified range Module Secondary Module secondary is OK Resistance is low or 0 ohms Module secondary is shorted Replace module Resistance is high or infinity ohms Module secondary is open Replace module 20 690 01 Rev KohlerEngines com 37 Electrical System BATTERY CHARGING SYSTEM NOTE Obse
60. essive wear or distortion Check valves and valve seats for evidence of deep pitting cracks or distortion Check running clearance between valve stems and guides Hard starting or loss of power accompanied by high fuel consumption may be symptoms of faulty valves Although these symptoms could also be attributed to worn rings remove and check valves first After removal clean valve heads faces and stems with a power wire brush Then carefully inspect each valve for defects such as warped head excessive corrosion or worn stem end Replace valves found to be in bad condition Valve Guides If a valve guide is worn beyond specifications it will not guide valve in a straight line This may result in burned valve faces or seats loss of compression and excessive oil consumption To check valve guide to valve stem clearance thoroughly clean valve guide and using a split ball gauge measure inside diameter Then using an outside micrometer measure diameter of valve stem at several points on stem where it moves in valve guide Use largest stem diameter to calculate clearance If intake clearance exceeds 0 038 0 076 mm 0 0015 0 0030 in or exhaust clearance exceeds 0 050 0 088 mm 0 0020 0 0035 in determine whether valve stem or guide is responsible for excessive clearance Maximum 1 D wear on intake valve guide is 6 135 mm 0 2415 in while 6 160 mm 0 2425 in is maximum allowed on exhaust guide Guides are not remova
61. ew rings are installed original pin can also be reused but new piston pin retainers are required Piston pin is part of piston assembly if pin boss or pin are worn or damaged a new piston assembly is required Ring failure is usually indicated by excessive oil consumption and blue exhaust smoke When rings fail oil is allowed to enter combustion chamber where it is burned along with fuel High oil consumption can also occur when piston ring end gap is incorrect because ring cannot properly conform to cylinder wall under this condition Oil control is also lost when ring gaps are not staggered during installation When cylinder temperatures get too high lacquer and varnish collect on pistons causing rings to stick which results in rapid wear A worn ring usually takes on a shiny or bright appearance 20 690 01 Rev Disassembly Inspection and Service Scratches on rings and pistons are caused by abrasive material such as carbon dirt or pieces of hard metal Detonation damage occurs when a portion of fuel charge ignites spontaneously from heat and pressure shortly after ignition This creates two flame fronts that 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 Preignition is
62. g replacement of crank gear will be necessary Remove gear by pulling it off key and crankshaft Inspect crankshaft bearing journal surfaces for wear scoring grooving etc If they show signs of damage or are out of running clearance specifications crankshaft must be replaced Inspect crankshaft keyways If worn or chipped replacement of crankshaft will be necessary Inspect crankpin for wear score marks or aluminum transfer Slight score marks can be cleaned with crocus cloth soaked in oil If wear limits are exceeded it will be necessary to replace crankshaft Balance Weight Disassembly If necessary First and Second Generation Balance Weight Assembly can be separated from crankshaft Disassemble only if required 1 Remove crank gear from crankshaft and carefully remove key from keyway 2 For first generation balance weight assembly remove guide shoe from guide pin on flywheel side of assembly For second generation balance weight assembly remove link from guide pin on PTO side of assembly 3 Remove long hex flange screw securing two balance weight halves together on crankshaft Note orientation of all parts Guide pin is on flywheel side for balance weight design with closure plate side guide shoe Guide pin is on PTO side for balance weight design with lower control link Hold guide pin with wrench or torx bit socket as required Do not hold or damage outside diameter O D of guide pin 4 Mark weights for p
63. g disassembly refer to Governor Spring Location charts Connect choke linkage from carburetor to actuating lever of speed control bracket 2 Attach speed control bracket to mounting locations on engine with M6 screws Position bracket as marked during disassembly Torque screws to 11 0 N m 95 in Ib into new holes or 7 5 N m 65 in Ib into used holes 20 690 01 Rev Reassembly Early Style Governor Spring Location inc Corp a poa e a pa o E po A le a x A A High Speed RPM Soverned idle Governor Throtle Fever Red Spring Alignment Current Style Governor Spring Location A High Speed Governed Idle RPM Governor Throttle Lever Red Sprin Alignment RPM Lever Hole Hole pring Hole 20 690 01 Rev KohlerEngines com 73 Reassembly Install Fuel Pump if eguipped NOTE If fuel pump is attached to air cleaner base fuel lines and pulse line should still be connected to fuel pump Connect pulse line to pulse fitting and secure with clamp 1 Attach fuel pump mounting bracket to speed control bracket with two M5 screws Torgue screws to 6 5 N m 55 in Ib into new holes or 4 0 N m 35 in Ib into used holes 2 Attach fuel pump to bracket so pulse fitting is oriented in four o clock position Secure with two M6 screws Torque screws to 9 5 N m 84 in Ib into new holes or 5 9 N m 52 in Ib into used holes Do not over tighten 3 Connect pulse and fuel lines to fuel pump and secure wi
64. gaged while flywheel is rotating starter pinion and flywheel ring gear may clash resulting in damage to starter If starter does not turn engine over shut starter off immediately Do not make further attempts to start engine until condition is corrected Do not jump start using another battery See your Kohler authorized dealer for trouble analysis 1 Fora Cold or Warm Engine Place throttle choke control into fast choke ON position This will also place choke into ON position 2 Make sure equipment is in neutral 3 Activate starter switch Release switch as soon as engine starts 4 For Operation After engine starts move throttle choke control from fast choke ON position and set desired engine operating speed between slow and fast position 28 KohlerEngines com High Speed RPM Adjustment Speed Control Bracket Details Speed Control Bracket Mounting Screw Recommended maximum no load high speed RPM for most engines is 3300 RPM Actual high speed RPM depends on application Refer to equipment manufacturer s instructions for specific information 1 Make sure throttle cable is adjusted properly see Throttle Cable Adjustment 2 Start engine and allow it to warm up Place throttle control lever into fast or high speed position Turn choke adjusting screw out counterclockwise so there is clearance from choke lever and that contact cannot occur during Step 4 3 Early Models Early models use a
65. harness failed in open circuit mode DSAI or DSAM malfunction Empty fuel tank Faulty electronic control unit Faulty ignition coil s Faulty spark plug s Fuel pump malfunction vacuum hose clogged or leaking Fuel shut off valve closed Ignition module s faulty or improperly gapped Insufficient voltage to electronic control unit Interlock switch is engaged or faulty Key switch or kill switch in OFF position Low oil level Quality of fuel dirt water stale mixture e SMART SPARK malfunction e Spark plug lead s disconnected Engine Starts But Does Not Keep Running e Faulty carburetor Faulty cylinder head gasket Faulty or misadjusted choke or throttle controls Fuel pump malfunction vacuum hose clogged or leaking Intake system leak Loose wires or connections that intermittently ground ignition kill circuit e Quality of fuel dirt water stale mixture e Restricted fuel tank cap vent Engine Starts Hard e Clogged fuel line or fuel filter e Engine overheated e Faulty ACR mechanism e Faulty or misadjusted choke or throttle controls e Faulty spark plug s e Flywheel key sheared e Fuel pump malfunction vacuum hose clogged or leaking Interlock switch is engaged or faulty e Loose wires or connections that intermittently ground ignition kill circuit e Low compression e Quality of fuel dirt water stale mixture e Weak spark 16 KohlerEngines com Engine Will Not
66. haust valve and engine operates at full power When engine is stopped spring returns flyweight control pin assembly to compression release position ready for next start Benefits As a result of reduced compression at cranking speeds several important benefits are obtained 1 Manual retractable starting is much easier Without ACR manual starting would be virtually impossible 2 Electric start models can use a smaller starter and battery which are more practical for application 3 ACR eliminates need for a spark retard advance mechanism A spark retard advance mechanism would be required on engines without ACR to prevent kickback which would occur during starting ACR eliminates this kickback making manual starting safer 4 Choke control setting is less critical with ACR If flooding occurs excess fuel is blown out opened exhaust valve and does not hamper starting 5 Engines with ACR start much faster in cold weather than engines without ACR 6 Engines with ACR can be started with spark plugs which are worn or fouled Engines without ACR are more difficult to start with those same spark plugs Cam Gears Inspection and Service Inspect gear teeth and cam lobes of intake and exhaust cam gears If lobes exhibit excessive wear or teeth are worn chipped or broken replacement of cam gear s will be necessary KohlerEngines com 57 Disassembly Inspection and Service Balance Weight Piston Assembly Components
67. hen drawn into exhaust manifold and any damage or decomposition of hoses secondary air muffler where it mixes with any unburned hydrocarbons valve or exhaust system parts should be replaced which then burn in heat of muffler A hose is connected between a carburetor port and a diaphragm chamber in secondary air valve Carburetor vacuum moves diaphragm to close valve when air induction is not reguired primary idle 48 KohlerEngines com 20 690 01 Rev Emission Compliant Systems Remove Inlet Screen Inlet Components Remove inlet screen from secondary air valve assembly by grasping inlet screen at base and gently pulling away from valve assembly 2 Use a soft brush to remove debris from screen 3 Run water through inlet screen in reverse direction 4 To reinstall push inlet screen onto barb of secondary air valve assembly An audible click will be heard when inlet screen is properly reinstalled 20 690 01 Rev KohlerEngines com 49 Disassembly Inspection and Service Accidental Starts can cause severe injury or Before working on engine or equipment disable engine as death follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery Disconnect and ground spark plug lead s before servicing k T AT OiFivDipsick B Debris Screen BlowerHousing D FuelPump TE Cylinder Head Baffle F Rectif
68. ic on crankshaft Again take two measurements 90 to each other 3 Running clearance is eccentric diameter subtracted from balance weight bearing diameter step 1 minus step 2 If measurements are outside maximum wear limits listed in Specifications affected component s must be replaced Measuring Balance Weight Guide Pin and Guide Shoe to Closure Plate Guide Channel Running Clearance 1 Use an outside micrometer and measure outside width of balance weight guide shoe 2 Use an inside micrometer telescoping gauge or similar tool and measure width of guide channel in closure plate Record these dimensions 3 Use an outside micrometer again and measure O D of balance weight guide pin 4 Use a split ball gauge or dial calipers and measure I D of corresponding hole in guide shoe Record these dimensions If any of measurements taken are outside maximum wear limits listed in Specifications affected component s must be replaced Remove Governor Cross Shaft 1 Remove hitch pin and washer located on outside of governor cross shaft 2 Slide shaft inward and remove it through inside of crankcase Be careful not to lose small washer in inside portion of shaft Remove PTO and Flywheel Side Oil Seals Use a seal puller to remove PTO and flywheel side oil seals Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments and deep scratches or nicks Check cylinder wa
69. ier Ill compliant it may be fitted with a Kohler supplied canister vapor recovery system or a system developed and installed by Original Equipment Manufacturer OEM Details on Kohler system are included below Operation Maintenance Fuel vapors travel from fuel tank through tubing to On Kohler supplied canisters breather filter can be carbon canister On intake stroke of engine fuel vapors removed and cleaned with hot soapy water dried and are drawn in through a port in carburetor and burned reinstalled Do not oil breather screen This is done with fuel charge periodically or if system operation is suspect Carbon canister is sealed and requires no maintenance In some applications or installations OEM will have installed a different canister or fuel vapor recovery system See OEM equipment documentation for service or maintenance information 20 690 01 Rev KohlerEngines com 47 Emission Compliant Systems SECONDARY EMISSION COMPLIANT SYSTEM Twin Secondary Air Induction System Secondary Air Hose To Exhaust ns Valve Assembly e Manifold nu Hose To Carburetor m Inlet Screen For engine to be Tier III compliant it may be fitted with a secondary air induction system SAI Operation Maintenance Intake pulse of engine activates secondary air valve Air inlet screen in secondary air valve can be removed Air is drawn through an inlet screen of secondary air cleaned and reinstalled If inspection of system reveals valve Air is t
70. itch tester should indicate continuity switch closed 2 Gradually increase pressure to switch As pressure increases through range of 2 5 psi tester should indicate a change to no continuity Switch open Switch should remain open as pressure is increased to 90 psi maximum 3 Gradually decrease pressure through range of 2 5 psi Tester should indicate a change to continuity switch closed down to 0 psi 4 Replace switch if it does not operate as specified 34 KohlerEngines com OIL PRESSURE Testing On some models engine oil pressure can be tested using an oil pressure tester Follow instructions included with tester Pressure can be tested by removing oil filter and installing tester adapter on mounting pad or by removing Oil Sentry pressure switch or pipe plug and threading tester hose directly into mounting hole 20 690 01 Rev SPARK PLUGS A CAUTION al Electrical Shock can cause injury Gg Do not touch wires while engine is running Spark Plug Component and Details A WireGauge B Spark Plug Ground Electrode D Gap NOTE Do not clean spark plug in a machine using abrasive grit Some grit could remain in spark plug and enter engine causing extensive wear and damage Engine misfire or starting problems are often caused by a spark plug that has improper gap or is in poor condition Engine is equipped with following spark plugs 0 76 mm 0 03 in Thread Size 19 1 mm 3 4 in
71. l line Check fuel tank cap vent fuel pickup screen in line filter shut off valve and fuel line Correct any observed problem and reconnect line Fuel line condition Check for a clogged fuel line If fuel line is unobstructed check for overfilled crankcase and or oil in pulse line If checks don t reveal cause of problem replace pump 22 KohlerEngines com 20 690 01 Rev Fuel System CARBURETOR A WARNING Gasoline is extremely flammable and its vapors can i explode if ignited Store gasoline only in approved Explosive Fuel can cause fires and severe containers in well ventilated unoccupied buildings away burns from sparks or flames Spilled fuel could ignite if it comes Do not fill fuel tank while engine is hot or in contact with hot parts or sparks from ignition Never use running gasoline as a cleaning agent Walbro One Barrel Carburetor Components A Choke Lever and Shaft Choke Plate A and B Choke Return Spring C ChokePlate D Choke Plate Fuel Inlet Needle Bowl Retaining Screw E Fostpn roi Soew Fuel Shut Off e Sema H Fuel Bow I Float J BowGasket Low Idle Speed Adjusting Spring and L Bowl Retaining Screw Screw Float Pin Fuel Shut Off Solenoid ll Float JJ Low Idle Speed Adjusting Spring and Screw Bowl Retaining Screw Gasket Fuel Bowl Bowl Gasket 20 690 01 Rev KohlerEngines com 23 Fuel System These engines are eguipped with eith
72. l pump and secure with hex flange screws Torque screws to 5 9 N m 52 in Ib Do not over tighten 2 Connect inlet outlet and pulse lines to their respective fittings on pump Secure with clamps Air Cleaner Base Mounted Fuel Pump 1 Install new fuel pump pressing fuel pump onto bracket past locking tabs 2 Connect inlet outlet and pulse lines to their respective fittings on pump Secure with clamps KohlerEngines com 97 Fuel System FUEL SYSTEM TESTS When engine starts hard or turns over but will not start fuel system might be causing problems Test fuel system by performing following test 1 Check for fuel in combustion chamber 3 Check operation of fuel pump a Disconnect and ground spark plug lead a Remove fuel line from inlet fitting of carburetor b Close choke on carburetor b Crank engine several times and observe flow c Crank engine several times d Remove spark plug and check for fuel at tip 2 Check for fuel flow from tank to fuel pump a Remove fuel line from inlet fitting of fuel pump b Hold line below bottom of tank Open shut off valve if equipped and observe flow Condition Conclusion Fuel at tip of spark plug Fuel is reaching combustion chamber No fuel at tip of spark plug Check fuel flow from fuel tank step 2 Fuel flows from fuel line Check for faulty fuel pump step 3 If fuel pump is working check for faulty carburetor Refer to Carburetor No fuel flow from fue
73. ll for scoring In severe cases unburned fuel can wash necessary lubricating oil off piston and cylinder wall Piston rings make metal to metal contact with wall causing scuffing and scoring Scoring of cylinder wall can also be caused by localized hot spots from blocked cooling fins or from inadequate or contaminated lubrication If cylinder bore is scored worn tapered or out of round resizing may be possible Use an inside micrometer or telescoping gauge to determine amount of wear refer to specifications If wear exceeds published limits a 0 08 mm 0 003 in oversize piston is available If cylinder will not clean up at 0 08 mm 0 003 in oversize a short block or replacement engine will need to be considered 20 690 01 Rev Disassembly Inspection and Service Honing Detail 23 33 Crosshatch While most commercially available cylinder hones can be used with either portable drills or drill presses use of a low speed drill press is preferred as it facilitates more accurate alignment of bore in relation to crankshaft counter bore Honing is best accomplished at a drill speed of about 250 RPM and 60 strokes per minute After installing coarse stones in hone proceed as follows 1 Lower hone into bore and after centering adjust it so stones are in contact with cylinder wall Use of a commercial cutting cooling agent is recommended 2 With lower edge of each stone positioned even with lowest edge of bore sta
74. losure plate e and crankcase controls crankshaft endplay no Lubricate outside diameter and lip of flywheel end oil shimming is required Do not use RTV sealant in seal Support closure plate and install oil seal Using a place of gasket A NSA o NOTE Engines with first generation balance weight seal bore Apply grease to outside flat surfaces of balance weight guide shoe Position guide shoe so solid end is toward crankshaft Make sure guide shoe stays in this position during step 2 Closure Plate Fastener Torque Sequence 1 Make sure sealing surfaces of crankcase and closure plate are clean dry and free of any nicks or burrs Install a new closure plate gasket onto crankcase 2 Ensure gasket cover plate and governor gear assembly have been properly assembled to closure plate Start closure plate onto crankcase Be sure guide shoe models with First Generation Balance Weight is aligned with guide channel in closure plate and cam shafts and governor gear shaft are aligned with their mating bearing surfaces As closure plate is lowered into final position rotate crankshaft slightly to help engage governor gear 3 Install screws securing closure plate to crankcase with any clamps for wiring harness and sheathed RFI suppression spark plug lead 5 location if equipped If wiring harness was separated from closure plate route harness through clamps and slot in closure plate Close clamps to retain harness 4 Torque closu
75. ly checking replacing spark plugs no maintenance or timing adjustments are necessary or possible Mechanical systems do occasionally fail or break down Refer to Troubleshooting to determine root of a reported problem Reported ignition problems are most often due to poor connections Before beginning test procedure check all external wiring Be certain all ignition related wires are connected including spark plug leads Be certain all terminal connections fit snugly Make sure ignition switch is in run position Fixed Ignition System This system uses a capacitive discharge CD coil Ignition timing and spark remains constant regardless of engine speed Timing of spark is controlled by location of flywheel magnet group as referenced to engine TDC A typical fixed ignition system consists of e 1 magnet assembly which is permanently affixed to flywheel e 1 electronic capacitive discharge ignition module which mounts on engine crankcase e 1 kill switch or key switch which grounds module to stop engine e 1 spark plug 36 KohlerEngines com 20 690 01 Rev Electrical System Electronic Ignition System Tests NOTE Ignition tester must be used to test ignition on these engines Use of any other tester can result in inaccurate findings Battery on unit must be fully charged and properly connected before performing tests a battery that is hooked up or charged backward will crank engine but it won t have spark Be certain dri
76. lywheel of CS series engines Flywheel Puller SE Tools KLR 82408 For properly removing flywheel from engine Flywheel Strap Wrench SE Tools KLR 82409 For holding flywheel during removal 20 690 01 Rev KohlerEngines com 13 Tools and Aids TOOLS Description Source Part No Hydraulic Valve Lifter Tool Kohler 25 761 38 S For removing and installing hydraulic lifters Ignition System Tester Kohler 25 455 01 S For testing output on all systems including CD Inductive Tachometer Digital Design Technology Inc For checking operating speed RPM of an engine DTI 110 Offset Wrench K and M Series Kohler 52 455 04 S For removing and reinstalling cylinder barrel retaining nuts Oil Pressure Test Kit Kohler 25 761 06 S For testing verifying oil pressure on pressure lubricated engines Radiator Tester Kohler 25 455 10 S For pressure testing radiator and cap on Aegis liquid cooled engines Rectifier Regulator Tester 120 volt current Kohler 25 761 20 S Rectifier Regulator Tester 240 volt current Kohler 25 761 41 S For testing rectifier regulators Components of 25 761 20 S and 25 761 41 S Design Technology Inc CS PRO Regulator Test Harness DTI 031 Special Regulator Test Harness with Diode DTI 033 Spark Advance Module SAM Tester Kohler 25 761 40 S For testing SAM ASAM and DSAM on engines with SMART SPARK Starter Servicing Kit All Starters SE Tools KLR 82411 For removing and reinstalling drive retaining rings an
77. m so oil ring moves from compressor into bore in one smooth quick motion Otherwise oil ring rails may spring out and jam between ring compressor and top of bore Guide connecting rod down and rotate crankshaft to mate journals Install rod cap Install screws and torque in 2 increments first to 5 5 N m 50 in Ib finally to 11 5 N m 100 in Ib KohlerEngines com 65 Reassembly Cam Closure Plate Components es Cl Gasket In E CamGears E e CamLevers H fc HN Closure Plate Gasket J GerotorGears K E M IN o Ea Oil Pump Cam Shaft Intake Governor Gear Install Cam Levers Install two cam levers as shown Dimple for seating push rod must face up Secure each cam lever using an M6 screw Torque screws to 7 5 N m 65 in Ib Lubricate dimple and bottom side of cam lever with light grease or oil Cam Shaft Pin Regulating Pin Governor Gear Shaft 66 KohlerEngines com Install Exhaust Cam Shaft and Cam Gear Drive Pin Locations for Exhaust Cam Shaft 3 I ZZZZZTAZZ ZZZLZ LLL ZZN a Se SS CLLLE DEL ZZZZZZZ LZA Exhaust Cam Shaft B 3 mm Diameter Pin ET Hole Location 1 E Hole Location 2 If drive pins were removed from exhaust cam shaft follow same procedure used earlier for intake cam shaft and reinstall them 2 Apply a dab of grease to formed groove in thrust washer Slide washer onto cam shaft so short drive pin is seated in groove Grease will hold washer in position
78. me are approved e Do not add oil to gasoline e Do not overfill fuel tank e Do not use gasoline older than 30 days KohlerEngines com STORAGE If engine will be out of service for 2 months or more follow procedure below 1 Add Kohler PRO Series fuel treatment or equivalent to fuel tank Run engine 2 3 minutes to get stabilized fuel into carburetor failures due to untreated fuel are not warrantable 2 Change oil while engine is still warm from operation Remove spark plug s and pour about 1 oz of engine oil into cylinder s Replace spark plug s and crank engine slowly to distribute oil 3 Disconnect negative battery cable 4 Store engine in a clean dry place 20 690 01 Rev Engine Dimensions 162 64 6 403 VALVE COVER VIEW CARBURETOR OIL DRAIN PLUG GROUND Lue 84 50 m 116 42 MOUNTING BOSS 3 327 4 584 122 46 4 821 25 400 s 25 376 S KEYWAY m 1 000 6 3170 e WIDTH SS eh EY AA REGULATOR 327 81 RECTIFIER 12 906 OPTIONAL 10 00 LIFTING 394 POINT 3 25 TO SPARK 128 PLUG U 153 7 ei 5 08 sz 68 00 B 2 677 66 04 2 600 TO STARTER STUD 96 00 3 780 CORED FOR M 6 SELF TAPPING SCREW Y 20 25 MM MIN 21 82 GROUND LUG S LOCATION 21 62 859 851 KEYWAY DEPTH 302 48 11 909 63 33 2 493 FUEL PUMP OPTIONAL AIR FILTER AND COV
79. mit 67 140 mm 2 6430 in Pin O D New 11 950 11 975 mm 0 4705 0 4715 in Max Wear Limit 11 900 mm 0 4685 in Guide Shoe Width New 17 85 17 90 mm 0 703 0 705 in Max Wear Limit 17 75 mm 0 6988 in 12 000 12 025 mm 0 4724 0 4734 in Max Wear Limit 12 050 mm 0 4744 in Linkage Pin O D Crankcase Second Generation Balance Weight New 11 964 11 975 mm 0 4710 0 4715 in Max Wear Limit 11 900 mm 0 4685 in Balance Weight Linkage Second Generation Balance Weight New 11 985 12 010 mm 0 4719 0 4728 in Max Wear Limit 12 035 mm 0 4738 in Cam Gears End Play 0 5 1 5 mm 0 019 0 059 in Running Side Clearance 0 02 0 13 mm 0 001 0 005 in Cam Gear to Cam Shaft Running Assembly 0 02 0 10 mm 0 001 0 004 in Closure Plate Balance Weight Guide Channel Width New 17 95 18 05 mm 0 707 0 711 in Max Wear Limit 18 13 mm 0 714 in gt Values are in Metric units Values in parentheses are English equivalents gt Lubricate threads with engine oil prior to assembly 8 KohlerEngines com 20 690 01 Rev Specifications CLEARANCE SPECIFICATIONS SV470 SV530 SV590 SV591 SV471 SV540 SV600 SV601 SV480 SV541 SV610 SV620 Connecting Rod Connecting Rod to Crankpin Running Clearance New 0 03 0 055 mm 0 0012 0 0022 in Max Wear Limit 0 07 mm 0 0025 in Connecting Rod to Crankpin Side Clearance 0 25 0 59 mm 0 0098 0 0232 in Connecting Rod to Piston Pin Running Clearance 0 015 0 02
80. mounted to speed control bracket and other is mounted to air cleaner base Fuel pump has two internal chambers separated by a diaphragm Air chamber is connected to engine crankcase by a rubber hose Fuel chamber has an inlet from fuel tank and an outlet to carburetor Inlet and outlet each have an internal one way check valve Alternating negative and positive pressures in crankcase activate pump When piston moves upward in cylinder negative pressure vacuum is created in crankcase and in air chamber of pump Diaphragm flexes toward negative pressure and suction draws fuel past inlet check valve into fuel chamber Downward movement of piston causes a positive pressure in crankcase and air chamber pushing diaphragm in opposite direction putting pressure on fuel Inlet check valve has now closed so fuel is forced past outlet check valve to carburetor 20 690 01 Rev Fuel System Repair Pulse fuel pumps are not serviceable and must be replaced when faulty Removal Speed Control Bracket Mounted Fuel Pump 1 Disconnect inlet outlet and pulse lines from fuel pump Mark lines for proper reassembly 2 Remove screws attaching fuel pump Air Cleaner Base Mounted Fuel Pump 1 Remove dipstick and blower housing 2 Disconnect inlet outlet and pulse lines from fuel pump Mark lines for proper reassembly 3 Remove fuel pump from bracket Installation Speed Control Bracket Mounted Fuel Pump 1 Install new fue
81. mpression stroke insert correct size flat feeler gauge see below between appropriate valve stem and rocker arm Tighten adjustment nut with a wrench until a slight drag is felt on feeler gauge Hold nut in position and torgue set screw T15 Torx drive to 5 5 N m 50 in Ib To prevent damage to nut torque Torx screw only Perform adjustment procedure on other valve Clearance Specifications Valve Intake Valve 0 127 mm 0 005 in Exhaust Valve 0 178 mm 0 007 in 20 690 01 Rev Reassembly Install Valve Cover Valve Cover Torque Sequence 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 Install a new valve cover gasket followed by valve cover Position any brackets mounted on valve cover and start seven mounting screws 3 Torque valve cover screws to 11 0 N m 95 in Ib into new holes or 7 5 N m 65 in Ib into used holes using sequence shown Valve Cover with RTV RTV Overlap Area 1 2 way between holes NOTE Always use fresh sealant Using outdated sealant can result in leakage Refer to Tools and Aids for important information on sealant dispenser NOTE To ensure proper adhesion of sealant to both sealing surfaces perform step 3 immediately 5 minutes maximum after application of RTV 1 Prepare sealing surface of cylinder head and valve cover 2 Apply a 1 6 mm 1 16 in bead of sealant to valve
82. n chipped or cracked teeth If one or more of these problems is noted replace governor gear Gear is held onto governor shaft by molded tabs which are damaged when gear is removed Never reuse gear once it has been pulled from shaft Replace governor shaft only if it is damaged or worn Remove Governor Shaft 1 Remove blower housing flywheel and cooling fan 2 Remove stator and crankshaft key 3 Remove closure plate screws and closure plate 4 Rotate engine to top dead center aligning timing marks on crankshaft and cam gears 5 Remove governor gear assembly and regulating pin from closure plate with two small screwdrivers 6 Locate governor pin from flywheel side With a small punch drive pin out of closure plate This could also be done with a press Do not remove governor pin with a vise grip or pliers you may damage closure plate 7 Remove any old gasket material from mating surfaces of crankcase and closure plate Use an aerosol gasket remover to help loosen any old gasket material Do not scrape surfaces as any scratches nicks or burrs can result in leaks Install Governor Shaft Governor Shaft Components and Details Sa at it SSS aes D 44 50 mm 1 750 in To Gasket Surface Before Oil Passage Cover Plate and Gasket are Assembled B Governor Gear Shaft 56 KohlerEngines com 1 Install new pin by pressing or lightly tapping it into closure plate It must be installed so that it protrudes 44
83. n regulator knob clockwise increase direction until gauge needle is in yellow set area at low end of scale Connect tester quick connect to adapter hose While firmly holding engine at TDC gradually open tester valve Note gauge reading and listen for escaping air at combustion air intake exhaust outlet and crankcase breather o EE Condition Conclusion Gauge reading in low green zone Gauge reading in moderate yellow zone Engine is still usable but there is some wear present Customer should start planning for overhaul or replacement Gauge reading in high red zone Rings and or cylinder have considerable wear Engine should be reconditioned or replaced 20 690 01 Rev KohlerEngines com 19 Air Cleaner Intake AIR CLEANER Paper Element These systems are CARB EPA certified and components 1 Remove element from base replace element should not be altered or modified in any way l 2 Install element with pleated side out and seat rubber seal onto edges of base Reinstall air cleaner cover and secure with knobs BREATHER TUBE Ensure both ends of breather tube are properly connected AIR COOLING A WARNING ol Hot Parts can cause severe burns And stm DO not touch engine while operating or just after stopping Never operate engine with heat shields or guards removed Proper cooling is essential To prevent over heating clean screens cooling fins and other external surfaces of engine Avoid sprayi
84. nd procedures when installing flywheel 2 KohlerEngines com 20 690 01 Rev Maintenance MAINTENANCE INSTRUCTIONS Accidental Starts can cause severe injury or Before working on engine or equipment disable engine as death follows 1 Disconnect spark plug lead s 2 Disconnect Disconnect and ground spark plug lead s negative battery cable from battery before servicing Normal maintenance replacement or repair of emission control devices and systems may be performed by any repair establishment or individual however warranty repairs must be performed by a Kohler authorized dealer MAINTENANCE SCHEDULE Every 25 Hours or Annually e Service replace low profile precleaner Air Cleaner Intake e Replace air cleaner element if not equipped with precleaner Air Cleaner Intake Every 100 Hours or Annually e Replace air cleaner element if not equipped with precleaner Air Cleaner Intake e Change oil and filter Lubrication System e Remove cooling shrouds and clean cooling areas Air Cleaner Intake Every 100 Hours e Replace fuel filter e Check that all fasteners are in place and components are properly secured Reassembly Every 200 Hours e Have valve lash checked adjusted Reassembly Every 500 Hours e Replace spark plug and set gap Electrical System 1 Perform these procedures more frequently under severe dusty dirty conditions 2 Have a Kohler authorized dealer perform this service
85. ne Serial No 332740003 and lower use a rubber outlet between oil pump outlet and lower bearing area Some models use an open seal with an internal passage to feed oil to lower bearing Some models use a closed or solid seal and crankshaft is crossed drilled to feed oil to lower bearing Engine Serial No 332740003 and higher outlet of oil pump is closed and no rubber seal is used 1 Remove thrust washer s and cam gears from cam shafts Later models will have a thrust washer on exhaust side only 2 Remove screws securing cam levers to crankcase Mark cam levers for proper reassembly 3 Pull exhaust side cam shaft and slotted thrust washer out of crankcase 4 If engine contains an internal drain back tube unhook it from oil pump and pull it out of crankcase passage Check for cracks brittleness or damage Replace if questionable in any way 5 Remove screws securing oil pump and intake side cam shaft to crankcase If a drain back tube is used it may be unhooked and removed separately or together with oil pump Carefully pull upward on cam shaft to remove assembly from crankcase cavity A small rubber oil pump outlet seal on outlet of oil pump may become dislodged during removal Do not lose it 6 If necessary oil pump can be separated from intake side cam shaft Provide appropriate support for shaft and drive out lower pin Oil pump assembly can then be removed from cam shaft Oil Pump Assembly and Pressure Relief
86. ng water at wiring harness or any electrical components Refer to Maintenance Schedule Air Cleaner Components Air Cleaner Base B Paper Element C Precleaner_ D Ar Cleaner Cover E Air Cleaner Knob NOTE Operating engine with loose or damaged air cleaner components could cause premature wear and failure Replace all bent or damaged components NOTE Paper element cannot be blown out with compressed air Loosen knobs and remove air cleaner cover Precleaner if equipped 1 Remove precleaner 2 Replace or wash precleaner in warm water with detergent Rinse and allow to air dry 3 Saturate precleaner with new engine oil squeeze out excess oil 4 Reinstall precleaner into cover aligning hole in precleaner with upper cover knob 20 KohlerEngines com 20 690 01 Rev Typical carbureted fuel system and related components include e Fuel tank Fuel lines In line fuel filter Fuel pump Carburetor Fuel from tank is moved through in line filter and fuel lines by fuel pump Fuel then enters carburetor float bowl and is drawn into carburetor body and mixed with air This fuel air mixture is then burned in engine combustion chamber FUEL RECOMMENDATIONS Refer to Maintenance FUEL LINE Low permeation fuel line must be installed on carbureted Kohler Co engines to maintain EPA and CARB regulatory compliance FUEL PUMP Some engines are equipped with one of two optional pulse fuel pumps One is
87. not strike module Recheck i ith a feeler gauge and readjust if necessary module as far away from flywheel as possible OP l Tighten screws sufficiently to keep module in Final air gap 0 203 0 305 mm 0 008 0 012 in position 6 Connect kill lead to tab terminal on ignition module Rotate flywheel to align magnet with ignition module Install Ignition Module Rotate flywheel so magnet is away from ignition module bosses Using screws install ignition module to crankcase bosses with kill terminal up Move N 20 690 01 Rev KohlerEngines com 71 Reassembly 7 If equipped with a sheathed RFI suppression spark plug lead place lead in retaining clip so braided wires will be in direct contact with clip when closed Carefully close clip with a pliers until a 0 127 mm 0 005 in gap exists between ends Do not pinch or flatten clip Install Spark Plug 1 Check gap using wire feeler gauge Adjust gap to 0 76 mm 0 03 in 2 Install plug into cylinder head 3 Torque plug to 27 N m 20 ft Ib Install Heat Deflector Carburetor Linkage and Air Cleaner Base 1 If carburetor mounting stud was removed reinstall it in outer cylinder location closest to head Use an E5 Torx socket or two nuts tightened together and turn stud in until tight 2 Make sure all gasket surfaces are clean and free of any nicks or damage 3 Install a new intake gasket onto carburetor stud then install heat deflector or c
88. nstall it into keyhole slot in top of crankcase 3 Install a new cylinder head gasket 4 Install cylinder head and start six screws Install thick washer on screw closest to exhaust port 5 Using torque sequence shown torque cylinder head screws in two stages initially to 20 5 N m 180 in Ib and finally to 41 0 N m 360 in Ib Install Rocker Arms and Push Rods NOTE Installation and seating of push rods into cam lever recesses during this sequence is critical Position engine with cylinder head up if possible to aid with proper installation of push rods and rocker arms and adjusting valve lash NOTE If being reused push rods should always be installed in their original position 1 Position push rod guide plates on cylinder head with extruded edges down over push rod bores Secure by installing rocker arm pivot studs Torque studs to 13 5 N m 120 in Ib 2 Apply grease to contact surfaces of rocker arms and adjusting nuts and install them onto pivot studs 3 Note mark or tag identifying push rod as either intake or exhaust Apply grease to ends of push rods Insert push rods into push rod bores and seat lower end into dimpled recess of cam levers lt may be necessary to lift or shift lower end of push rod slightly and feel rod seats into recess Once seated hold it in place as you position rocker arm Push rod must stay in recess while rocker arms are positioned and adjusted 4 With engine at TDC of co
89. o shaft from outside as far as it will go Secure by inserting hitch pin in machined groove Install Oil Pump Assembly and Intake Cam Shaft Assembled Intake Cam Shaft Details ARA R A ON OSO OOOO O OOO E SR ODAS AS A K S S OS AS SNA Oil Pump Assembly D Hole Location 2 Hole Location 1 ns 25 mne 64 KohlerEngines com If oil pump assembly was removed from intake cam shaft reassemble it onto shaft Press fit of drive pins in holes may be one of two designs One style of tube has drive pin holes machined to be a clearance slip fit on one side and a press fit on other accepting smooth style drive pins Later design tubes have holes uniformly machined and use knurled style drive pins Support cam shaft clearance holes up when applicable and install shorter 2 5 mm 0 098 in diameter pin in outer hole closest to bottom end Center pin in shaft If it was removed install and center longer 3 mm 0 118 in diameter drive pin into upper hole Lightly grease gerotor gears and install into oil pump with short drive pin fitted into slot of inner gear Pump Outlet Seals 4 Determine if outlet of oil pump is open or closed Open style pumps require use of a rubber seal between pump outlet and lower main bearing area Some models use an open style seal with an internal passage to feed oil to lower bearing Some models use a closed seal without an oil passage and crankshaft is crossed drilled for lower bearing lubric
90. ood level of suds If suds break down during cleaning discard dirty water and start again with more hot water and detergent Following scrubbing rinse cylinder with very hot clear water dry it completely and apply a light coating of engine oil to prevent rusting Measuring Piston to Bore Clearance Piston Detail 8 mm 0 314 in NOTE Do not use a feeler gauge to measure piston to bore clearance it will yield inaccurate measurements Always use a micrometer Before installing piston into cylinder bore it is necessary that clearance be accurately checked This step is often overlooked and if clearances are not within specifications engine failure will usually result Use following procedure to accurately measure piston to bore clearance 1 Use a micrometer and measure diameter of piston 8 mm 0 314 in above bottom of piston skirt and perpendicular to piston pin 2 Use an inside micrometer telescoping gauge or bore gauge and measure cylinder bore Take measurement approximately 63 5 mm 2 5 in below top of bore and perpendicular to piston pin 3 Piston to bore clearance is difference between bore diameter and piston diameter step 2 minus step 1 62 KohlerEngines com 20 690 01 Rev Reassembly Balance Weight Piston Assembly Components Crankshaft Crank Gear Key Balance Weight Washer e map Hl Olseal Piston Ring Set o First Generation Second Generation Balance Weigh
91. ove bracket toward carburetor To decrease high speed RPM move bracket away from carburetor 5 Tighten speed control bracket mounting screws Recheck speed with a tachometer and readjust if necessary Torque mounting screws as follows Into new hole 11 0 N m 95 in Ib Into used hole 7 5 N m 65 in Ib 6 Adjust choke see Choke Adjustment which follows Choke Adjustment This procedure must follow High Speed Adjustment just described If not already completed perform that operation first 1 Turn choke adjusting screw out counterclockwise until it no longer contacts choke lever 2 Then turn it back in clockwise until it just makes contact 3 While observing choke link move throttle control lever to low idle slow position then back to full throttle fast Choke link should not move as throttle moves through normal range If it does back adjusting screw out until it no longer moves 4 Move throttle control lever to choke position Check if choke has fully closed by placing your finger on right side of lower end of choke lever choke link and applying gentle pressure towards carburetor If controls have been properly set link should not move SEPARATE THROTTLE AND CHOKE CONTROL Some engines are equipped with separate throttle and choke controls This allows you to adjust choke and throttle controls individually 20 690 01 Rev Fuel System Install Separate Control Cables Spee
92. ove retaining screw washer and fan mounting plate securing fan and flywheel to crankshaft 3 Carefully lift cooling fan to disengage two drive pins and remove it from flywheel Flywheel with Puller Holes 1 Remove flywheel from crankshaft using a puller 2 Remove flywheel key from crankshaft Flywheel without Puller Holes 1 Remove flywheel from crankshaft by pulling from under ring gear with large gear puller 2 Remove flywheel key from crankshaft Flywheel Inspection Inspect flywheel for cracks and check keyway for wear or damage Replace flywheel if cracked If flywheel key is sheared or keyway is damaged replace crankshaft flywheel and key Inspect ring gear for cracks or damage Ring gears are not available separately Replace flywheel if ring gear is damaged Remove Stator NOTE To disconnect B or stator leads from wiring harness connector insert a small screwdriver or similar narrow flat blade and bend down locking tang of terminal s Gently pull lead s out of connector Remove screws securing stator to closure plate bosses 20 690 01 Rev Disassembly Inspection and Service Cylinder Head Components Be i 7 Bee LL L i m JE dee KE a Gasket e Ve Cylinder Head Screw F Push Rod ES KS e Valve SpringRetainer H Vale Stem Seal 1 Valve Spring J Valve Spring Cap K Rocker m L SetScrew CM Valve Cover Gasket N Valve Cover O
93. pen Replace stator Resistance is high in both Diode or stator winding is directions open Continue testing 4 Disconnect braking lead green from wiring harness 4 cn lighting lead yellow from wiring With engine running in fast setting measure voltage SE from braking lead to ground using an AC voltmeter Measure resistance from lighting lead to ground using an ohmmeter Condition Conclusion Condition Conclusion Voltage is 35 volts or Stator is OK Circuitry on more unit that grounds braking lead is shorted Voltage is less than 35 Test stator using an volts ohmmeter Resistance is Stator winding is OK approximately 0 15 ohms diode is open Replace diode Resistance is 0 ohms Stator winding is shorted K 5 With engine stopped measure resistance from Resistance is infinity Stator winding or lead is ec Sd open Replace stator braking lead to ground using an ohmmeter Condition Conclusion Resistance is 0 2 0 4 Stator is OK ohms Resistance is 0 ohms Stator is shorted Replace stator Resistance is infinity Stator or lighting lead is ohms open Replace stator 40 KohlerEngines com 20 690 01 Rev Electrical System Wiring Diagram 9 or 15 Amp Regulated Battery Charging System O A a El spero F Optional Fuel Solenoid ional O Seny y Bendi starer a Engine Connector Starter Solenoid KD Ground To Kill Lead Key Switch D Es Optional Fuse Rectifier Regulator Flywhe
94. posing retaining ring 3 Holding spring retainer in retracted position assemble inner halves of removal tool around armature shaft with retaining ring in inner groove Slide collar over inner halves to hold them in position 4 Thread center screw into removal tool until you feel resistance Use a wrench 1 1 8 or adjustable to hold base of removal tool Use another wrench or socket 1 2 or 13 mm to turn center screw clockwise Resistance against center screw will tell you when retaining ring has popped out of groove in armature shaft 5 Remove drive components and drive nut collar from armature shaft paying attention to sequence If splines are dirty clean them with solvent 6 Splines should have a light film of lubricant Relubricate as necessary with Kohler bendix starter lubricant Reinstall or replace drive components assembling them in same sequence as they were removed Retaining Ring Installation 1 Position retaining ring in groove in one of inner halves Assemble other half over top and slide on outer collar 2 Be certain drive components are installed in correct sequence onto armature shaft 3 Slip tool over end of armature shaft so retaining ring inside is resting on end of shaft Hold tool with one hand exerting slight pressure toward starter Tap top of tool with a hammer until you feel retaining ring snap into groove Disassemble and remove tool 4 Squeeze retaining ring with pliers to compre
95. r mixture to engine under all operating conditions Main fuel jet is calibrated at factory and is not adjustable Idle fuel adjusting needles are also set at factory and normally do not need adjustment Low Idle Speed RPM Adjustment NOTE Actual low idle speed depends on application Refer to eguipment manufacturer s recommendations Low idle speed for basic engines is 1200 RPM Place throttle control into idle or slow position Turn low idle speed adjusting screw in or out to obtain allow idle speed of 1200 RPM 75 RPM Governed Idle Speed Adjustment if eguipped 1 Hold governor lever away from carburetor so throttle lever is against idle speed RPM adjustment screw of carburetor Start engine and allow to warm up then adjust screw to set approximately 1200 RPM Check speed using a tachometer Turn adjustment screw inner clockwise in to increase or counterclockwise out to decrease speed 2 Release governor lever and check that throttle lever is in idle position Turn governed idle adjustment screw to obtain equipment manufacturer s recommended idle speed 1500 1800 RPM Some engines have a bendable tab that is used to set this speed A pliers should be used to bend this tab to achieve recommended speed Governed idle speed RPM is typically 300 RPM approximate higher than low idle speed 3 Move throttle lever to wide open full throttle position and hold in this position Turn high speed screw to obtain intende
96. re plate fasteners to 24 5 N m 216 in Ib using sequence shown Install Closure Plate Gasket Closure Plate and Wiring Harness 20 690 01 Rev KohlerEngines com 67 Reassembly Cylinder Head Components A KE D mm es A We kg SS ES E Cyinder Head Sorew F PushRod ValveSpringRetainer H Valve Stem Seal Ci VaWve spring J Valve Spring Cap K Rocker m L SetScrew M Vaive Cover Gasket N Valve Cover 0 Screw P Rocker Arm Pivot a Rocker arm Stud R Push Rod Guide Plate Assemble Cylinder Head Install Cylinder Head Prior to assembly lubricate all components with engine Cylinder Head Torgue Seguence oil including tips of valve stems and valve guides Using a valve spring compressor install following items in order listed e Intake and exhaust valves e Valve spring caps e Valve springs e Valve spring retainers e Valve spring keepers NOTE Do not reuse cylinder head screws or gasket always replace with new parts NOTE If crankshaft has not been turned since installation of crank gear turn it one 1 complete revolution This will set piston at top dead center TDC of compression stroke for proper valve lash adjustment later 68 KohlerEngines com 20 690 01 Rev 1 Check to make sure there are no nicks or burrs on sealing surfaces of cylinder head or crankcase 2 Ifengine uses a drain back check ball i
97. rect oil viscosity type Internal wear or damage Low crankcase oil level Quality of fuel dirt water stale mixture 20 690 01 Rev Engine Loses Power e Dirty air cleaner element e Engine overheated e Excessive engine load e Restricted exhaust e Faulty spark plug s e High crankcase oil level e Incorrect governor setting e Low battery e Low compression e Low crankcase oil level e Quality of fuel dirt water stale mixture Engine Uses Excessive Amount of Oil e Loose or improperly torqued fasteners e Blown head gasket overheated e Breather reed broken e Clogged broken or inoperative crankcase breather e Crankcase overfilled e Incorrect oil viscosity type e Worn cylinder bore e Worn or broken piston rings e Worn valve stems valve guides Oil Leaks from Oil Seals Gaskets Breather reed broken Loose or improperly torqued fasteners Piston blow by or leaky valves Restricted exhaust 20 690 01 Rev Clogged broken or inoperative crankcase breather Troubleshooting EXTERNAL ENGINE INSPECTION NOTE It is good practice to drain oil at a location away from workbench Be sure to allow ample time for complete drainage Before cleaning or disassembling engine make a thorough inspection of its external appearance and condition This inspection can give clues to what might be found inside engines and cause when it is disassembled e Check for buildup of dirt and
98. roper reassembly and carefully slide balance weights off crankshaft eccentrics 60 KohlerEngines com Balance Weight Assembly Measurement Locations Crankshaft DEIA Balance Weight Balance Weight Bearing Surface Guide Shoe NOTE These procedures apply only to First and Second Generation Balance Weights Third Generation Balance Weight should not be disassembled Balance weight assembly counterbalances crankshaft weights and internal forces during operation to minimize vibration Several key areas of balance weight must be checked before installation and use Additionally mating components crankshaft eccentrics and closure plate guide channel must also be inspected for wear or damage Use these procedures to check balance weight and matching components Balance Weight to Eccentric Clearance NOTE Do not use a feeler gauge to measure balance weight to eccentric clearance Before balance weight assembly is reassembled to crankshaft running clearance to crankshaft eccentrics must be accurately checked Failure to maintain required clearances will result in vibration or engine failure 20 690 01 Rev Measuring Balance Weight to Crankshaft Eccentric Ring s Clearance 1 Use an inside micrometer telescoping gauge or bore gauge and measure inside diameter of balance weight bearing surface Take two measurements 90 to each other on each weight 2 Then use an outside micrometer and measure across each eccentr
99. rt drill and honing process Move hone up and down while resizing to prevent formation of cutting ridges Check size frequently Make sure bore is cool when measuring 3 When bore is within 0 064 mm 0 0025 in of desired size remove coarse stones and replace with burnishing stones Continue with burnishing stones until within 0 013 mm 0 0005 in of desired size and then use finish stones 220 280 grit and polish to final size A crosshatch should be observed if honing is done correctly Crosshatch should intersect at approximately 23 33 off horizontal Too flat an angle could cause rings to skip and wear excessively too steep an angle will result in high oil consumption 4 After honing check bore for roundness taper and size Use an inside micrometer telescoping gauge or bore gauge to take measurements These measurements should be taken at three locations in cylinder at top middle and bottom Two measurements should be taken perpendicular to each other at 3 different locations KohlerEngines com 61 Disassembly Inspection and Service Clean Cylinder Bore after Honing Proper cleaning of cylinder walls following honing is critical Grit left in cylinder bore can destroy an engine in less than one hour of operation after a rebuild Final cleaning operation should always be a thorough scrubbing with a brush and hot soapy water Use a strong detergent capable of breaking down machining oil while maintaining a g
100. rve following guidelines to avoid damage to electrical system and components e Make sure battery polarity is correct A negative ground system is used e Disconnect rectifier regulator plug and or wiring harness plug before doing any electric welding on eguipment powered by engine Disconnect all other electrical accessories in common ground with engine e Prevent stator AC leads from touching or shorting while engine is running This could damage stator Most engines are eguipped with either a 9 or 15 amp regulated battery charging system Some have a 3 amp regulated system with a 70 watt lighting circuit Wiring Diagram 3 Amp Regulated Battery Charging System 70 Watt Lighting A Red D Spark Plug F optan Fuel Solenoid m Engine Connector Starter Solenoid Optional Oil Sentry Switch Shutdown or Bendix Starter Indicator Optional Oil Sentry Gate ES Fi Indicator e E Ground To Kill Lead o Optional Fuse D Battery Rectifier Regulator Accessory Key Switch D ER Sentry Flywheel 8 KohlerEngines com 20 690 01 Rev O Electrical System 3 Amp 70 Watt Lighting Stator NOTE Zero ohmmeter on each scale to ensure accurate readings Voltage tests should be made with engine running at full throttle with no load Battery must be fully charged To test charging system for no charge to battery To test charging system for no lights 1 With engine running in fast setting measure voltage 1
101. s on stator brake relay which shorts charging AC stator leads to produce a magnetic field that will counter or resist rotation of flywheel This added resistance to rotation decreases amount of time it takes for application deck blades to come to a full stop 20 690 01 Rev As Kohler blade stop stator brake circuit often is operated in conjunction with other application circuits relay in Kohler circuit is specially configured with a 680 ohm resistor in parallel with relay coil This is done to negate transient voltage signals that would be normally created by interrupting relay current once relay has been activated Therefore relay replacement must only be made with properly identified relay Troubleshooting Stator Brake System Stator Brake and Relay Harness Connections min d qe H 4 Stator Assembly e Wire Tie Black 20 690 01 Rev iring Harness Stator Leads to Rectifier Regulator D Stator Leads Push Wing Mount Black Electrical System Problems that could occur with Kohler portion circuit generally could be caused by two component failures or an incorrect relay replacement which will create following conditions To test for dead battery Brake relay has failed and is keeping stator shorted so no charge current can be passed from rectifier regulator to battery eventually allowing battery to discharge 1 Check battery voltage using a test meter with application off 2 Check battery vol
102. s with one screw and one mounting stud only Apply hand pressure to keep parts from shifting then carefully remove alignment pin and install DRY long M6 thread forming screw DO NOT OIL Check to make sure all gaskets are still IN proper position 72 KohlerEngines com c Torque nut s to 5 5 N m 48 in lb Torque screw to 8 0 N m 70 in lb into a new hole or 5 5 N m 48 in Ib into a used hole do not over tighten An M6 screw for upper tab will be installed when blower housing is mounted 10 Attach breather hose to valve cover and air cleaner base Install and Adjust Governor Lever Speed Control Bracket Details E T 8 d a R Y de a E Speed Control OE Choke Linkage D Throttle Linkage EI Fuel Pump Bracket F Fuel Pump NOTE It is recommended a new governor lever be installed whenever removal is performed 1 Install governor lever onto governor shaft with lever section up Connect throttle linkage using black linkage bushing 2 Move governor lever toward carburetor to limit of its travel wide open throttle and hold in this position Do not apply excessive pressure flexing or distorting linkage Grasp cross shaft with a pliers and turn shaft counterclockwise as far as it will go Torque nut to 7 0 8 5 N m 60 75 in Ib Mounting Speed Control Bracket 1 Attach governor spring to governor lever and throttle lever of speed control bracket in original holes If holes were not marked durin
103. sembly controls choke and engine speed with a single lever Throttle Cable Adjustment Throttle Choke Controls Details 20 690 01 Rev Speed Control Bracket Alignment Hole Details Cable Clamp Later Models Alignment Hole for Alignment Hole 3000 RPM and Higher Current Models Alignment Hole for 2901 3100 RPM Alignment Hole for Less Than 3000 RPM 20 690 01 Rev Alignment Hole for 3101 3750 RPM Alignment Hole for 2400 2900 RPM Fuel System NOTE Choke is placed ON by moving throttle control slightly past fast position If throttle control does not have a designated choke ON position be sure to leave sufficient throttle control travel past fast position This will enable choke to be placed ON Loosen control cable clamp Place throttle control lever of equipment into fast or high speed position Actuating tab of choke lever should be just below end of choke adjusting screw Early Models Early models use a single alignment hole to set engine RPM Align hole in throttle lever with hole in speed control bracket by inserting a pencil or 6 35 mm 1 4 in drill bit Later Models Later models use a new control assembly identified by two opposing alignment holes close to throttle lever pivot instead of one Based upon intended high speed RPM setting throttle cable adjustment must be made by matching hole in control lever with correct alignment hole Use lower left side hole for high
104. single alignment hole to set engine RPM Align hole in throttle lever with hole in speed control bracket by inserting a pencil or 6 35 mm 1 4 in drill bit Later Models Later models utilize a new design control assembly identified by two opposing alignment holes close to throttle lever pivot instead of one Based upon intended high speed RPM setting throttle cable adjustment must be made matching hole in control lever with appropriate alignment hole Use lower left side hole for high speed settings 3000 RPM and above Use upper right side hole for high speed settings less than 3000 RPM Move throttle lever to align hole in lever with appropriate hole in control bracket Insert a pencil or a 6 35 mm 1 4 in drill bit to hold in position Current Models Current models use a new control assembly identified by three alignment holes close to throttle lever pivot Based upon intended high speed RPM setting throttle cable adjustment must be made by matching hole in control lever with correct alignment hole Use appropriate hole for corresponding high speed settings Move throttle lever to align hole in lever with correct hole in control bracket Insert a pencil or a 6 35 mm 1 4 in drill bit to hold in position 20 690 01 Rev 4 Loosen speed control bracket mounting screws Slide bracket forward or backward until desired high speed RPM is reached Check speed with a tachometer To increase high speed RPM m
105. speed settings above 3000 RPM Use upper right side hole for high speed settings lower than 3000 RPM Move throttle lever to align hole in lever with correct hole in control bracket Insert a pencil or a 6 35 mm 1 4 in drill bit to hold in position Current Models Current models use a new control assembly identified by three alignment holes close to throttle lever pivot Based upon intended high speed RPM setting throttle cable adjustment must be made by matching hole in control lever with correct alignment hole Use appropriate hole for corresponding high speed settings Move throttle lever to align hole in lever with correct hole in control bracket Insert a pencil or a 6 35 mm 1 4 in drill bit to hold in position Pull on outer shield of throttle control cable to remove any slack Tighten cable clamp securely KohlerEngines com 97 Fuel System Starting an Engine Eguipped with Unitized Throttle and Choke Control Starting Throttle Control Details Cold Engine or Warm Engine NOTE Do not crank engine continuously for more than 10 seconds at a time If engine does not start allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn out starter motor NOTE If engine develops sufficient speed to disengage starter but does not keep running a false start engine rotation must be allowed to come to a complete stop before attempting to restart engine If starter is en
106. ss it into groove 5 Assemble inner halves with larger cavity around spring retainer Slide collar over them and thread center screw in until resistance is felt 6 Hold base of tool with a 1 1 8 wrench and turn center screw clockwise with a 1 2 or 13 mm wrench to draw spring retainer up around retaining ring Stop turning when resistance increases Disassemble and remove tool Starter System Starter Disassembly 1 Remove drive components following instructions for servicing drive 2 Remove nut and insulating washer from positive brush lead stud 3 Remove thru bolts and recessed nuts 4 Remove commutator end cap and lift out brush carrier assembly with brushes and springs 5 Remove drive end cap then pull armature with thrust washer and wave washer if equipped out of starter frame Brush Replacement 1 Remove nut and insulating washer from positive _ brush lead stud 2 Remove thru bolts and captured hex nuts 3 Remove commutator end cap then pull brush carrier assembly out of frame Commutator Service Clean commutator with a coarse lint free cloth Do not use emery cloth lf commutator is badly worn or grooved turn it down on a lathe or replace armature Starter Reassembly 1 Place wave washer followed by thrust washer onto drive shaft of armature 2 Insert armature into starter frame Magnets will hold it in place 3 Align holes with spaces between magnets and install dri
107. t Balance Weight NOTE Make sure engine is assembled using all Make sure all traces of any cleaner are removed before specified torgue values torgue seguences and engine is assembled and placed into operation Even clearances Failure to observe specifications small amounts of these cleaners can guickly break down could cause severe engine wear or damage lubricating properties of engine oil Always use new gaskets Apply a small amount of oil to threads of critical fasteners before assembly unless a sealant or Loctite is specified or preapplied Check closure plate crankcase cylinder heads and valve covers to be certain all old gasket material has been removed Use gasket remover lacquer thinner or paint remover to remove any remaining traces Clean surfaces with isopropyl alcohol acetone lacquer thinner or electrical contact cleaner LA 20 690 01 Rev KohlerEngines com 6 Reassembly Install PTO Side Oil Seal PTO Seal Depth Details Y IAS ANO AT SER ARES EE AT AN APURO AER AE AE E EE EE VASO SOS ADO ALD MES SAE LT ES SCT O SOE ARTO MA SES S y UNA Ny l Seal Depth 5 5 mm 0 216 in Use a seal driver and install to a depth of 5 5 mm 0 216 in into crankcase Oil Seal Install Governor Cross Shaft 1 Place thin thrust washer onto governor cross shaft as far as it will go 2 Lightly lubricate shaft with oil and install it from inside crankcase 3 Slide thick thrust washer ont
108. t of ring gear as shown 2 Grind off any burrs or sharp edges 3 Invert segment and place it between ignition bosses on crankcase so tool teeth engage flywheel ring gear teeth Bosses will lock tool and flywheel in position for loosening tightening or removing with a puller 20 690 01 Rev Tools and Aids ROCKER ARM CRANKSHAFT TOOL B A spanner wrench to lift rocker arms or turn crankshaft may be made out of an old junk connecting rod 1 Find a used connecting rod from a 10 HP or larger engine Remove and discard rod cap 2 Remove studs of a Posi Lock rod or grind off aligning steps of a Command rod so joint surface is flat 3 Find a 1 in long capscrew with correct thread size to match threads in connecting rod 4 Use a flat washer with correct I D to slip on capscrew and approximately 1 in O D Assemble capscrew and washer to joint surface of rod KohlerEngines com 15 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 Clogged fuel line or fuel filter Diode in wiring
109. t will again overcome fuel pressure rising to predetermined setting and stop flow Slow and Mid Range At low speeds engine operates only on slow circuit As a metered amount of air is drawn through slow air bleed jets fuel is drawn through main jet and further metered through slow jet Air and fuel are mixed in body of slow jet and exit to idle progression transfer port chamber From idle progression chamber air fuel mixture is metered through idle port passage At low idle air fuel mixture is controlled by setting of idle fuel adjusting screws This mixture is then mixed with main body of air and delivered to engine As throttle plate opening increases greater amounts of air fuel mixture are drawn in through fixed and metered idle progression holes As throttle plate opens further vacuum signal becomes great enough at venturi so main circuit begins to work Main high speed At high speeds loads engine operates on main circuit As a metered amount of air is drawn through air jet fuel is drawn through main jet Air and fuel are mixed in main nozzles then enters main body of airflow where further mixing of fuel and air occurs This mixture is then delivered to combustion chamber Carburetor has a fixed main circuit no adjustment is possible 20 690 01 Rev Fuel System Carburetor Adjustments NOTE Carburetor adjustments should be made only after engine has warmed up Carburetor is designed to deliver correct fuel to ai
110. tage using a test meter with application operating at maximum speed Battery voltage should increase from engine off condition to engine full speed condition Condition Conclusion Voltage does not increase Shut down engine remove relay from its socket and re test at full engine speed If battery voltage does not increase with engine operating problem is likely not with stator brake relay Continue testing stator and rectifier regulator To test engine that will crank but will not start Brake stator relay is interacting with application safeties or reverse mow electronics preventing normal engine start up 1 Remove brake relay from its socket and attempt to restart engine Conclusion Relay is not correct for this application or transient protection resistor has failed Replace relay with correct component Problem may exist with application reverse mow circuit application safeties or with key switch keeping ignition shutdown line tied to engine ground Condition Engine starts Engine does not start 2 Remove engine shutdown kill lead from application wire harness and attempt to start engine again Condition Conclusion Engine does not start Fuel or ignition problem KohlerEngines com 43 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 start
111. tal M6 Fastener 11 6 N m 99 in Ib into new hole 7 7 N m 68 in Ib into used hole Cam Lever Fastener oN Oi into new hole 1 8 6 N i 8i into used hole gt Values are in Metric units Values in parentheses are English equivalents Exceeding maximum angle of operation may cause engine damage from insufficient lubrication Lubricate threads with engine oil prior to assembly 8 Any and all horsepower hp references by Kohler are Certified Power Ratings and per SAE J1940 8 J1995 hp standards Details on Certified Power Ratings can be found at KohlerEngines com 6 KohlerEngines com 20 690 01 Rev Specifications TOROUE SPECIFICATIONS SV470 SV530 SV590 SV591 SV471 SV540 SV600 SV601 SV480 SV541 SV610 SV620 Carburetor Fuel Bowl Retaining Screw Walbro 1 6 45 55 in Ib 5 Nikki 10 8 12 96 113 in Ib Closure Plate 24 5 Nim 216 in Tb Connecting Rod Cap Fastener torque in 2 increments 5 5 11 5 N m 50 100 in Ib Crankcase Oil Drain Plug 14 0 N m 125 in Ib Cylinder Head Fastener torque in 2 increments 20 5 41 0 N m 180 360 in Ib Rocker Arm Pivot Stud 13 5 N m 120 in Ib Rocker Arm Adjustment Nut Set Screw 5 5 N m 50 in Ib Electric Starter Thru Bolt 3 3 3 9 N m 30 35 in Ib Mounting Nut 3 6 N m 32 in Ib Nut top Positive Brush Lead Terminal 1 6 2 8 N m 15 25 in Ib Nut flange Positive Brush Lead Terminal 2 2 4 5 N m 20 40 in
112. ted Install flywheel onto crankshaft aligning keyway with key Be careful not to shift or unseat key Position fan onto flywheel so locating pins drop into corresponding recesses N 4 Install fan mounting plate onto fan aligning four cutouts followed by heavy flat washer and screw 20 690 01 Rev Reassembly 5 Use a flywheel strap wrench or holding tool to hold flywheel and torque screw For an M10 screw torque to 66 5 N m 49 ft Ib For an M12 screw torque to 88 0 N m 65 ft Ib External Engine Components AT orribesi B Dem KE TE Gyinder Head Bale F ReoiferRegulaor 6 Elecvic Starter H OllFilter DU Fuclriter Al Oi Sentry K Air Cleaner Cover L Precieaner m o a ES Ka w Fuel Pump Air Cleaner Element N Air Cleaner Base O Gasket P Carburetor GroundWire R _ Oil Drain Plug S Nikki Fuel Solenoid 3 Insert a 0 25 mm 0 010 in flat feeler gauge Install Electric Starter de A A between magnet and ignition module Loosen Install electric starter to closure plate and secure with screws so magnet pulls module against feeler nuts Make sure wires are clear of any moving parts and gauge torque nuts to 3 6 N m 32 in Ib Carburetor Spacer 4 Torque screws to 6 0 N m 55 in Ib into new holes or 4 0 N m 35 in Ib into used holes 5 Rotate flywheel back and forth checking for clearance between magnet and ignition module Make sure magnet does
113. th clamps Install Rectifier Regulator 1 Using M6 screws mount rectifier regulator onto crankcase bosses with cooling fins out Torque screws to 6 0 N m 55 in Ib into new holes or 4 0 N m 35 in Ib into used holes 2 Attach connector to rectifier regulator terminals Install Cylinder Head Baffle Attach cylinder head baffle to cylinder head using screws Torque screws to 10 2 12 4 N m 90 110 in Ib into new holes or 7 0 8 5 N m 62 75 in Ib into used holes Install Oil Sentry or Pipe Plug Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads of 1 8 pipe plug or adapter Install and tighten into port on closure plate Torque pipe plug to 4 5 5 0 N m 40 45 in Ib If a switch was installed apply sealant to threads of Oil Sentry switch and install into adapter center passage or closure plate behind blower housing Torque switch to 4 5 5 0 N m 40 45 in Ib Connect green wiring harness lead to terminal on switch Install Blower Housing and Debris Screen 1 Position blower housing on engine and route spark plug lead through underside slot 2 Check stator leads are within notch of blower housing Align mounting locations then install four M6 shouldered mounting screws If a flat washer was used under head on one screw install screw in location closest to oil fill dipstick Torque screws to 11 6 N m 99 in Ib into new holes or 7 7 N m 68 in
114. ting lead is should be measured about midscale on Rx1 range ohms open Replace stator Condition Conclusion Resistance is low in both Diode is shorted Replace directions diode Resistance is high in both Diode or stator winding is directions open Continue testing 4 Cut sleeving on charging lead to expose diode connections Measure resistance from stator side of diode to ground using an ohmmeter Condition Conclusion Resistance is Stator winding is OK approximately 0 5 ohms diode is open Replace diode Resistance is 0 ohms Stator winding is shorted Replace stator Resistance is infinity Stator winding or lead is ohms open Replace stator 20 690 01 Rev KohlerEngines com 39 Electrical System 3 Amp 70 Watt Braking Stator NOTE Zero ohmmeter on each scale to ensure accurate readings Voltage tests should be made with engine running at full throttle with no load Battery must be fully charged To test charging system for no charge to battery To test charging system for no lights and battery 1 With engine running in fast setting measure voltage charging braking system across battery terminals using a DC voltmeter 1 Make sure lights are not burned out Condition Conclusion To test battery charging system go to step 4 otherwise perform steps 2 and 3 only Voltage is more than 12 5 Charging system is OK volts Condition Conclusion Voltage is 12 5 volts or Stator or diode are Burne
115. uretor gasket then carefully remove heat deflector or carburetor spacer heat shield if equipped and gaskets from intake stud Heat deflector is made from a plastic that is quite brittle Do not pry on corners or you risk cracking breaking deflector If prying is necessary to loosen deflector carefully pry near intake stud only Remove mounting stud from cylinder only if required 8 Remove insert from intake port some models if separate from heat deflector KohlerEngines com 51 Disassembly Inspection and Service Flywheel Ignition Components A Flywheel Screw B Washer e Fan Mounting Plate D Fan E Magnet LEI Sot e ignition Module H Sator RSC 52 KohlerEngines com Remove Ignition Module 1 Disconnect kill lead from ignition module 2 Rotate flywheel magnet away from module 3 Remove RFI sheathed spark plug lead from retaining clip if so equipped 4 Remove screws and ignition module Remove Debris Screen Fan and Flywheel NOTE Always use a flywheel strap wrench or flywheel holding tool see Tools and Aids to hold flywheel when loosening or tightening flywheel and fan retaining fasteners Do not use any type of bar or wedge between fins of cooling fan as fins could become cracked or damaged NOTE Always use a puller to remove flywheel from crankshaft Do not strike crankshaft or flywheel as they could be cracked or damaged 1 Unsnap debris screen from cooling fan 2 Rem
116. uretors are eguipped with a fuel shut off solenoid Solenoid is attached to fuel bowl Solenoid has a spring loaded pin that retracts when 12 volts is applied to lead allowing fuel flow to main jet When current is removed pin extends blocking fuel flow Below is a simple test performed with engine off that can determine if solenoid is functioning properly 1 Shut off fuel and remove solenoid from carburetor When solenoid is loosened and removed gas will leak out of carburetor Have a container ready to catch fuel 2 Wipe tip of solenoid with a shop towel or blow with compressed air to remove any remaining fuel Take solenoid to a location with good ventilation and no fuel vapors present You will also need a 12 volt power source that can be switched on and off 3 Be sure power source is switched OFF Connect positive power source lead to red lead of solenoid Connect negative power source lead to solenoid body 4 Turn power source ON and observe pin in center of solenoid Pin should retract with power ON and return to its original position with power OFF Test several times to verify operation Carburetor Circuits Float Fuel level in bowl is maintained by float and fuel inlet needle Buoyant force of float stops fuel flow when engine is at rest When fuel is being consumed float will drop and fuel pressure will push inlet needle away from seat allowing more fuel to enter bowl When demand ceases buoyant force of floa
117. ve end cap onto front of frame 4 lf brush assembly is not being replaced position springs and brushes within their pockets in carrier move them to retracted position and install carton staples to retain them Replacement brushes come pre assembled in carrier housing retained with two carton staples 5 Hold brush holder assembly with positive brush lead stud up Align molded sections with corresponding cutouts in starter frame and slide brush carrier assembly into place Commutator will push carton staples out as brush assembly is inserted 6 Position commutator end cap over brush assembly aligning holes for stud terminal and thru bolts 7 Install thru bolts and hex nuts Torque to 3 3 3 9 N m 30 35 in lb 8 Install insulating washer and hex flange nut onto positive brush lead stud Make sure stud is centered and does not touch metal end cap Torque hex flange nut to 2 2 4 5 N m 20 40 in Ib After installation and connection of starter lead torque outer nut to 1 6 2 8 N m 12 25 in Ib do not over torque 9 Lubricate drive shaft with Kohler bendix starter drive lubricant Install drive components following instructions for servicing drive A6 KohlerEngines com 20 690 01 Rev Emission Compliant Systems EVAPORATIVE EMISSION COMPLIANT SYSTEM Carbon Canister System v Ps Fuel Tank Cap B Fuel Tank D Roll RO S D Carbon Canister Canister Breather e Filter To Carburetor For engine to be T
118. ve is in neutral and all external loads are disconnected Test Ignition Systems NOTE If engine starts or runs during testing you may need to ground kill lead to shut it down Because you have interrupted kill circuit it may not stop using switch Isolate and verify trouble is within engine 1 Locate connectors where wiring harnesses from engine and equipment are joined Separate connectors and remove white kill lead from engine connector Rejoin connectors and position or insulate kill lead terminal so it cannot touch ground Try to start engine to verify whether reported problem is still present Condition Possible Cause Conclusion Problem goes away Electrical System Check key switch wires connections safety interlocks etc Problem persists Ignition or Electrical System Leave kill lead isolated until all testing is completed Test for Spark NOTE To maintain engine speeds normally obtained during cranking do not remove engine spark plug 1 Make sure spark plug lead is connected to spark plug 2 Check condition of spark plug Make sure gap is set to 0 76 mm 0 030 in If plug is in good condition check adjust gap and reinstall 3 a Test for spark with ignition tester Disconnect spark plug lead and connect it to post terminal of tester Connect clip to a good ground not spark plug b Make sure engine ignition switch kill switch or key switch is in RUN position 4 Crank engine minimum speed 500 RPM and obs
119. ward loosened or removed from cross shaft Adjust as follows e Regulating pin contacts tab on cross shaft causing 1 Make sure throttle linkage is connected to governor shaft to rotate arm and throttle lever on carburetor e One end of cross shaft protrudes through crankcase Rotating action of cross shaft is transmitted to throttle 2 Loosen nut holding governor lever to cross shaft lever of carburetor through external throttle linkage 3 Move governor lever toward carburetor as far as it e When engine is at rest and throttle is in fast position will go wide open throttle and hold in this position tension of governor spring holds throttle plate open When engine is operating governor gear assembly is rotating Force applied by regulating pin against cross shaft tends to close throttle plate Governor spring tension and force applied by regulating pin balance each other during operation to maintain engine speed e When load is applied and engine speed and governor gear speed decreases governor spring tension moves governor arm to open throttle plate wider This allows more fuel into engine increasing engine speed As speed reaches governed setting governor spring tension and force applied by regulating pin will again offset each other to hold a steady engine speed 4 Grasp cross shaft with a pliers and turn shaft counterclockwise as far as it will go Torque nut to 7 0 8 5 N m 60 75 in Ib 20 690 01 Rev KohlerEngines com
120. witch 2 Remove pressure switch from center oil galley or adapter elbow of filter adapter casting or from closure plate Disconnect Spark Plug Lead Carefully pull on boot section and disconnect spark plug lead Remove Muffler 1 Remove nuts or 5 16 18 cap screws attaching muffler or exhaust system to engine Remove any attached brackets 2 Remove muffler and gasket from exhaust port Remove Cylinder Head Baffle Remove screws attaching cylinder head baffle to cylinder head and remove cylinder head baffle Remove Rectifier Regulator 1 Unplug connector from rectifier regulator 2 Remove screws securing rectifier regulator to crankcase Remove rectifier regulator Remove Electric Starter 1 Disconnect starter lead from terminal stud 2 Remove nuts securing starter to closure plate Remove starter Remove Air Cleaner 1 Disconnect inlet outlet and pulse lines from fuel pump if fuel pump is secured to air cleaner base Mark lines for proper reassembly 2 Loosen knobs and remove air cleaner cover 20 690 01 Rev Disassembly Inspection and Service 3 Remove precleaner if equipped and air cleaner element with formed rubber seal 4 Remove nut s and long mounting screw securing air cleaner base 5 Disconnect breather hose from valve cover and remove air cleaner base and gasket with fuel pump attached if equipped Remove External Governor Components Carburetor and Fuel Pump warning
121. ylinder piston rings or valves are worn Individual component available Design Technology Inc Adapter 12 mm x 14 mm Required for leakdown test on XT 6 engines DTI 731 03 Dealer Tool Kit Domestic Kohler 25 761 39 S Complete kit of Kohler required tools Components of 25 761 39 S Ignition System Tester Kohler 25 455 01 S Cylinder Leakdown Tester Kohler 25 761 05 S Oil Pressure Test Kit Kohler 25 761 06 S Rectifier Regulator Tester 120 V AC 60Hz Kohler 25 761 20 S Dealer Tool Kit International Kohler 25 761 42 S Complete kit of Kohler required tools Components of 25 761 42 S Ignition System Tester Kohler 25 455 01 S Cylinder Leakdown Tester Kohler 25 761 05 S Oil Pressure Test Kit Kohler 25 761 06 S Rectifier Regulator Tester 240 V AC 50Hz Kohler 25 761 41 S Digital Vacuum Pressure Tester Design Technology Inc For checking crankcase vacuum DTI 721 01 Individual component available Design Technology Inc Rubber Adapter Plug DTI 721 10 Electronic Fuel Injection EFI Diagnostic Software Kohler 25 761 23 S For Laptop or Desktop PC EFI Service Kit Kohler 24 761 01 S For troubleshooting and setting up an EFI engine Components of 24 761 01 S Design Technology Inc Fuel Pressure Tester DTI 019 Noid Light DTI 021 90 Adapter DTI 023 In line T Fitting DTI 035 Code Plug Red Wire DTI 027 Code Plug Blue Wire DTI 029 Shrader Valve Adapter Hose DTI 037 Flywheel Holding Tool CS SE Tools KLR 82407 For holding f

SV470-SV620 Service Manual

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