Kohler K91 Service Manual
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Kohler K91 Service Manual

Kohler K91 Service Manual

Single cylinder k series
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Table of Contents

See also: Owner's Manual , Operation & Maintenance Manual
Single Cylinder Engine
SERVICE MANUAL
K9J, KJ4J, KJ6J, KJSJ,
1(24J, K30J, K32J, K34J

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Summary of Contents for Kohler K91

  • Page 1 Single Cylinder Engine SERVICE MANUAL K9J, KJ4J, KJ6J, KJSJ, 1(24J, K30J, K32J, K34J...
  • Page 2 CONTENTS S ECTION General I nformation ..........S ECTION S pecial Tools .

  • Page 3: General Information

    SECTION 1 GENERAL INFORMATION SAFETY INFORMATION For Your Safetyl These safety precautions should be followed at all times. Failure follow these safety precautions could result in serious injury to yourself and others. AWARNING AWARNING AWARNING .��I I �m" Explosive Fuel Hot Parts Rotating Parts can cause fires and severe...
  • Page 4 AWARNING AWARNING AWARNING � ��� Accidental Starts Carbon Monoxide Sulfuric Acid in batteries can cause severe injury can cause severe nausea, can cause severe injury or death. fainting or death. or death. Disconnect and ground spark Charge only in well ventilation. Do not operate engine in plug lead before servicing.
  • Page 5 . ing . Refer to Figure 1 -1 . The significance of these n u mbers is shown below : KOHLER(�fJjl�TIlrJ[cq 00 !-iP MODEL NO 0000 :;, : ; ,��w�,� ;OM�N��'...
  • Page 6 OIL RECOMMENDATIONS NOTE: Using other than Service Class SF or SG oil or extending oil change intervals longer than Using the proper type and weight of oil in the engine recommended could cause engine damage crankcase a nd in the gear reduction unit is extreme­ which is not covered by the engine warranty.
  • Page 7 (up to a maxi m u m of 1 5% MTBE by and helps elim inate spoilage during refueling . vol ume) are approved as a fuel for Kohler engines . Other gasoline/ether blends are not a pproved .
  • Page 8 HORSEPOWER (Maximum RPM) En ine Model Bore x Slroke GENERAL Displacement Cu. In. Max. Op� Shall 0.0, BALANCE Maximum GEAR End Play 1.0. Sleeve Installed CAMSHAFT Play ,0051.010 .005/,010 .0051.010 .0051.010 .0051.010 .0051.020 .0051,010 Red To Crank.- .0011.002 .0011.002 .0011.002 Pin '6 .001/,0025 ,001/.002...
  • Page 9 HORSEPOWER (Max. RPM) Engine Model K161 New 140 In. lb •. New 260 In. Ibo. Used 100 In. lb •. Posi-Iock® CONNECTING Used 200 In. Ibs. RODS<D Capscrew@ 140 In. Ibs. 200 In. Ibs. 285 In. Ibs. SPARK PLUGS 18·22 Ibs.

  • Page 10: Special Tools

    Figu re 2-1 or the tools can be ordered individually. Contact your Kohler Engine Distributor for price and availability . Figure 2 - 1 . S pecial S e rvice Tool Kit 2 . 1...
  • Page 11 VALVE SERVICE TOOLS & TOOL NO. N AME ILLUSTRATION APPLICATION 11918 VALVE SEAT PULLERS � Re moval of valve seats, Use 11726 3222 11915 slide hammer & adapter, 11913 forc i n g screw FORC I N G SCREW Used with valve seat 11726 11913 11915...
  • Page 12 SEAL AND BEARING INSTALLERS & TOOL NO. NAME ILLUSTRATION APPLICATION 3242 SEAL PROTECTOR SLEEVE KIT Used on cran kshaft when i n stalli n g 12020 .75" 12021 1.00 seals to prevent damage 12022 1.25 12126 1.12 12127 1.50 12128 1.44 Used to i n stall &...
  • Page 13 KIT NO. 3211 -A TOOL USAGE CHART MODEL ( SERIES) K" " PART NO NAME & ,... ,... ,... ,... ,... ,... ,... ,... ,... ("II ("II ,... ,... ("II '<t '<t � ..:. ..:. � � VALVE TOOLS � �...
  • Page 14 Digital Voltmeter Figure 2 - 2 . Eng i n e Analysis Kit The Kohler E ngin e Analysis Kit contains a selection The voltmeter. tachometer. thermometer and en­ of i n stru me n ts which will enable you to measure gine analyzer feature state of the art e lectronic critical items that relate to engine performance.

  • Page 15: Periodic Maintenance

    SECTION PERIODIC MAINTENANCE RE QUIRED MAINTENANCE These required maintenance procedures should be performed at the frequency stated in the table : Required Maintenance Frequency Check Oil Level ............Daily Clean Grass Screen .
  • Page 16 The oil level should be up to. but not over. the Precleaner " F " mark on the dipstick. Refer to Figure 3-1 . If so equipped . wash and reoil the precleaner every 25 operating hours (more often under ex­ tremely dusty.
  • Page 17 ""- - PREC LEA NER (OPT ION) Figure 3-2 . Air Cleaner Components. NOTE : Damaged , worn , or loose a ir cleaner com­ ponents could allow unfiltered air i nto the engine Wire Gauge causing premature wear and failure . Replace a l l damaged o r worn components .
  • Page 18 ( Part N o . 52 357 01) to splines. Drain Plug (Oil Level Check) NOTE : Kohler starter drive lubricant (Part N o . 52 357 01) must be used on all Kohler electric starter d rives . The use of other lubricants can cause the d rive to stick o r bind .
  • Page 19 K161, K1 8 1 Fig ure 3-6. Cleaning Cylinder Head And 15-20 ft. Ibs. Combustion Chamber. 1. Remove the cylinder head baffle and cyl1nder � head . 2 . Clean away combustion deposits using a wooden or plastic scraper. 3. Reinstall the cylinder head using a new gasket . ©...
  • Page 20 3 . Measure valve-to-tappet clearance with a flat STORAGE feeler gauge . On M odel K9 1 , K 1 4 1 , K 1 6 1 , K 1 8 1 -If the If the engine will be out of service for approxi­ clea rance is too small, remove the valves and mately two months or more , use the following...

  • Page 21: Troubleshooting

    SECTION TROUBLESHOOTING TROUBLESHOOTING G UIDE Battery is discharged . Safety interlock switch is .. engaged " . When trouble occurs , be sure to check the simple Loose or faulty wires o r connections . causes which , at first , may seem too obvious to Faulty keyswitch o r ignition switch .
  • Page 22 C LEANING THE E N G I N E Low compressio n . E n g i n e Uses Excessive Amount o f O i l After inspecting t h e external condition o f t h e e n ­ gine, clean it thoroughly before disassembling .

  • Page 23: Compression Test

    Kohler Engine Analysis Kit is recommended . Refer side . If there is no vacuum {level in engine to the " Special Tools " section for more informa­ side is the same as in open side) or a positive tion .
  • Page 24 SECTION 5 AI R CLEANER AND AI R I NTAKE SYSTEM K series engi nes are equipped with a hig h-density AIR CLEANER S ERVICE paper air cleaner element . Engines of some speci­ P recleane r fications are also equipped with an oiled foam precleaner that surrounds the paper element .
  • Page 25 Replace a dirty, bent or damaged element with a K 1 8 1 New Look engines only , make s u re ele­ new genuine Kohler element. Handle new ment cover is not bent o r damaged . Check elements carefully; d o not use if surfaces are that element cover nut is secured tightly to bent or d amaged .
  • Page 26 NOTE : Damaged , worn or loose air cleaner com­ I nstall base gasket and place filter on air horn. ponents could allow u nfiltered air into the engine Add engine oil to filter and fill to the OIL LEVEL causing premature wear and failure .
  • Page 27 SECTION 6 FUEL SYSTEM AN D GOVERNOR FUEL SYSTEM - GASOLIN E chamber where it is compressed , then ign ited by the spark plug . The typical gasoline fuel system and related com­ T roubleshooting ponents include the f uel tank with vented cap , shutoff valve with screen , in-line fuel filte r , fuel Use the following procedure to check that fuel is pump (some models) , carburetor and intercon­...
  • Page 28 Operation The mechanical fuel pump is operated by a lever that rides on the engine camshaft . The lever transmits a pumping action to the flexible d ia­ phragm i nside the pump body . The pumping ac­ tion draws fuel in through the inlet check valve on the downward stroke of the diaphragm .
  • Page 29 tor . This gives a leaner fuel-to-air mixt ure . Turning the adjusting needles (counterclockwise) in­ creases the supply of fuel to the carburetor . This gives a richer fuel-to-air mixture . Setting the nee­ dles m idway between the lean and rich positions will usually give the best results .
  • Page 30 M id p o i n t Figure 6-5. Optimum Low Idle Fuel Setting. Disassembly (Refer to Figure 6-7) Figure 6-6. Kohler-Built Adjustable Jet Remove the bowl retaining screw. retaining Carburetor. screw gasket and fuel bow l . 6. 4...
  • Page 31 NOTE: D o not s ubmerge carburetor i n cleaner o r solvent when fiber or rubber seals are installed . Figure 6-7. Kohler-Built Adjustable Jet The cleaner may damage these seal s . Carburetor - Exploded View. I n s pect ion...
  • Page 32 # 2-56x7/32" o r # 3-48x7l32" 2 Styles For Models B'ass Sc'ew K91 - K 1 8 1 , 1 /2" Carbo Throttle Shaft -4 Styles For Models K24 1 - K341 & KT1 7- K T 1 9, 1 " Ca,b.
  • Page 33 File off any bu rrs which may have been left o n Compare the old shaft with the new shafts in the choke shaft when t h e screws were re­ the kit . Select the appropriate new shaft and moved .
  • Page 34 Install Choke S haft Bushings Install a throttle shaft (without throttle lever) in carburetor body to use as a pilot : Install screws in the tapped holes that enter Models K9 1 - K 1 8 1 ( 1 /2 " Carb . ) ; Use the old the choke shaft bores u ntil the screws bottom throttle shaft removed previously .
  • Page 35 R eassembly Attach c hoke plate t o choke shaft. Make sure marks are aligned and plate is positioned prop­ Install the fuel inlet seat gasket and fuel inlet erly in the bore . Apply Loctite to threads of 2 seat into carburetor body.
  • Page 36 Check float-to-float hinge tower clearance: WALBRO FIXED/ADJU STABLE Invert the carburetor so the float tab rests on CARBURETOR 01 0 the fuel inlet needle . Insert a feeler " gauge between float and float h inge towers. If This section covers the idle adjustment , disassem­ the feeler gauge cannot be inserted , or there bly , cleaning , inspection , repair, and reassembly Walbro-built, side draft, fixed/adjustable...
  • Page 37 0 " l O D " N O T E T " ese will be el:her :ne I t " 'ottle Date Code* leve-: side of mounting f ange as s"own, c I o n : h e bot:ol'1 (fuel bow l ) s ee mo u �...
  • Page 38 • TROUBLESHOOTING Make sure the carburetor is. securely fastened to the engine using gaskets in good condition. If engine troubles are experienced that appear to be fuel system related , check the following areas • Make sure the air cleaner element is clean before adjusting or disassembling the carburetor.
  • Page 39 In general , turning the adjusting needles I n (clock­ wise) decreases the supply of fuel to the carbure­ I dle Speed tor. This gives a leaner fuel-to-air mixture . Turning Adjusting Screw the adjust f ng needles (counterclockwise) in­ creases the supply of fuel to the carburetor.
  • Page 40 PRELI M I NARY S En"INGS K-SERIES MODELS WALBRO WALBRO ADJUSTABLE JET KOHLER ADJUSTABLE JET High Idle Low Idle FIXED J ET Low Idle High Idle Low Idle 2 B DETERMD 2 B DETERMD 1 - 1 /2 turns 2 turns NOT APPL.
  • Page 41 DISASS EMBLY Refer To Fig ures and 6-22 . 6-1 7 Throttle plate Throttle shaft Throttle plate screws Breather fitting � ldle adjusting nee dle Idle nee dle � spring � Choke spring High speed Choke ball �"""Thro ttle adjusting spring Choke plate Carburetor Assembly...
  • Page 42 A . Pierce t h e welch plug with t h e t i p o f t h e tool . reassembly (refer to Figure 6-25) . Also take note of the choke plate position in bore , and CAUTION : To prevent damage to the carburetor , do the position of the choke lever.
  • Page 43 CLEANING REPAIR £ Always use new gaskets when servicing and rein­ WARNING: Flammable Solvents I stalling carburetors . Repair kits are available which include new gaskets and other components. These Carburetor cleaners and solvents are extremely kits are described below. flammable.
  • Page 44 CAUTION : If the detent ball does not drop through the tapped air cleaner base screw hole by its own weight , do not force it. Forcing the ball could permanently lodge it in the hole . Install the ball through the choke shaft bore instead .
  • Page 45 Install the idle speed adjusting screw and Install t h e new h i g h altitude main fuel jet and 1 2/ 1 6 In. lb. spring . torque to Reinstall the fuel inlet needle , float , and float Install t h e idle fuel adjusting needle a n d spring .
  • Page 46 SO L E NO I D , A NT I - D I ES E L I NG ( 45 435 01 ) � THROTTLE L I N KAGE *NOTE: Make sure idle speed scre� on carbure tor has been turned counterc lockwi s e unti l i t no longer contacts the throttle bracke t - - this a l lows the throt t le p late to c lose fu l ly .
  • Page 47 Do not operate engine without air cleaner as ing . always remove spark plug lead to prevent injury may result . engine from starting and to avoid personal in­ jury. Refer to Figure 6-32 . When checking choke operation . during crank- ON E L EA D TO START ER RELAY CHOKE...
  • Page 48 PROBLEM CAUSES SOLUTIONS Choke will not fully Choke spring not properly ad- Remove spring retainer and open . justed . with choke wide open windup spring 1 1 2 turn . Choke shaft fails t o move freely. Install new shaft assembly re- pair kit .
  • Page 49 The main components of the gas fuel system as NOTE : A soap bubble test is a good way to check used with Kohler K series eng ines are : for complete shutoff . If bu bbles ind icate that air is Liquified petroleum gas tank still flowing, turn the screw in one more full turn .
  • Page 50 Check that air flow stops when the primer is !� released. If air flow does n o t stop completely, loosen t h e adjustment screw lock nut and turn t h e adjust­ ment screw in until air flow stops , then one _ _ _ more full turn .
  • Page 51 Two Stage Regulator cient tension t o require approximately 1 0 psi pres­ sure on the internal side of the diaphragm to The two stage regulator used on Kohler engines is counteract the opening force due to the spring . •...
  • Page 52 If leaking persists, replace the reg ulator. I nitial Adjustment K91 , K 1 41 . K 1 6 1 , K 1 81 GOVERNOR Governors are adjusted at the factory. Further ad­...
  • Page 53 S peed Adjustment £ WARNING: Overspeed Is Hazardous! The maximum allowable speed for Model K91 is 4000 RPM. Models K161 and K181 are restricted to 3600 RPM maximum. Never tamper with the gover­ nor setting to increase engine speed above these limits.
  • Page 54 2 . Open the throttle to full speed and check en­ gine speed with a tachometer. Speed should Carburetor be approximately 4000 RPM for Model K91 and Throttle Lever 3 600 -RPM for Model K 1 6 1 or K 1 8 1 .
  • Page 55 spring holds the throttle valve ope n . When the en­ Pull the governor arm away from the carbure­ gine is operating (governor gear assembly is rotat­ tor as far as it will g o . ing) , the force applied by the regulating pin Grasp t h e e n d of cross shaft with pliers and against the cross shaft tends to close the throttle turn counterclockwise as far as it will g o .
  • Page 56 To increase sensitivity. increase the governor spring tension by moving the spring towards the cross shaft . To decrease sensitivity, and al low broader con­ tro l , decrease spring tension by moving the spring away from the cross shaft . Figure 6-46.
  • Page 57 GOV E R N O R ARM GOVE R N O R A R M B RACKET'---t t- S P E ED C ONTROL BRAC KET--it � � -++-..H I GH S P E ED S TO P Figure 6-48.
  • Page 58 S ensitivity Adjustment Stop the engine and check for free movement of the governor linkage from idle to full open Governor sensitivity is adjusted by repositioning the throttle. Remove excess paint from the gover­ governor spring in the holes in the governor arm . nor spring and make sure that there is no in­...
  • Page 59 . NOTE : Releasing handle when starter rope is ex­ MODEL K91 tended will shorten life of starter. Do not use starter in a rough manner, such as FAI RBAN KS-MORSE STARTERS jerking or pulling starter rope all the way out .
  • Page 60 Disassembly Spring holders furnished with replacement springs simplify the assembly procedure. Place If starting rope breaks or if starting spring fails, the spring in proper position as shown , with the following procedure should be followed . outside loop engaged around the pin . Then press the spring into cover cavity thus releas­...
  • Page 61 Press the starter into position and install the four screws with lock washers and flat wash­ ers . To Remove Starter Hold the starter assembly i n this centered po­ sition and securely tighten the four screws. Remove the five screws securing the starter assembly to blower housing .
  • Page 62 Remove the rope retainer from inside handle. � CAUTION: Spring Under Tension Untie the knot and remove the retainer and handle. Do not remove the center screw of the starter when replacing pawls. Removal of the center screw can Hold the pulley firmly with thumb and untie the cause the sudden and potentially dangerous release slip knot .
  • Page 63 5 . When all spring tension on the starter pu lley has been released , remove the rope from the pulley. Remove t h e center screw , washer, pawl cam , and brake spring . Rotate t h e pu lley clockwise 2 f u l l t u r n s . This will ensure the pu lley is d isengaged from the spring .
  • Page 64 The pulley is in position when the center shaft is extending slightly above the face of the pulley. not wind the pulley and recoil spring at this Use only genuine Kohler replacement parts time. specified in the Parts Manual . All components...
  • Page 65 CAST HOUSING MODELS Sheave Recoil Spring Rope Retainer Rope Exploded View. Figure 7 . 7...
  • Page 66 Remove the starter from engine . � CAUTION: Spring Under Tensionl Do not remove the center screw of the starter until the tension of recoil spring has been released. Re­ moving the center screw before releasing spring tension, or improper starter disassembly can cause the sudden and potentially dangerous release of the recoil spring.
  • Page 67 To Replace Recoil S p ring Replace all worn o r damaged components . � Use only genuine Kohler replacement parts CAUTION: Spring Under Tension! specified in the Parts Manual . All components shown in Figure 7- 1 1 are available as service Do not attempt to pull or pry the recoil spring from parts.
  • Page 68 Lift the housing a n d rap i t firmly against the Hook the spring hook over the post i n housing . Make sure the spring/c-ring is centered over the wooden surface . Repeat this procedu re u ntil spring pocket i n housing .
  • Page 69 starter housing leg reinforcements as the pul­ 1 1 . As a test , rotate the pawl retainer slightly ley is rotated later during reassembly. clockwise . Pressure from the return s pring should be felt . I n addition , the pawl retainer I nstall t h e pu lley onto the center shaft .
  • Page 70 1 8 . Slip the handle and rope retainer onto rope. Tie a single knot at the end of rope and install rope retainer into handle. Refer to Figure 7-1 2 . 1 9 . Untie the slip knot and pull the handle out until the rope is fully extended .
  • Page 71 SECTION 8 ELECTRICAL SYSTEMS AN D COMPON EN TS Battery ig nition with 1 5 Amp alternator IGNITION SYSTEMS Battery ignition with 30 Amp alternator Koh ler K series engines are fitted with one of three types of ignition systems . each avai lable in several Breakerless I g n ition System d ifferent version s .
  • Page 72 f()��- -- - MAGNETO I G N I T I ON H I GH TE NS I ON L E A D C O I L TO CON DE N S E R � TO B RE A KE R PO I NTS Figure Typical Flywheel Mag neto Ignition Coil And Stator.
  • Page 73 Battery Ignition System Operation NOTE: The preceding step is for timing lights using an alligator clip to connect to the spark plug. If the The battery ignition system operates in a manner light in use has a sharp prong on the spark plug similar to the magneto system .
  • Page 74 8-6. Kohler replacemen t . Use of the correct spark plug In some applications a 2 2 ohm. 1 12 watt resistor and gap setting is also important . The specified...
  • Page 75 vices . If a faulty trigger module is suspected , dis­ BRACKET connect and remove the trigger from the engine (PART OF and perform the following tests with a flashlight COIL) tester. Reset air gap when reinstalling trigger. Diode Test Turn tester switch ON and connect one lead to terminal and the other to the A terminal then reverse these leads--light should come on with...

  • Page 76: Spark Plugs

    Spark Plugs should be removed after every 1 00 hours of op­ eration for a check of its condition . At this time Engine misfire and starting difficulty are often the gap should be reset or the spark plug re­ caused by the spark plug being in poor condition placed as necessary.
  • Page 77 sp.r k PI U 9� Service the spark plug as follows . Clean the area around the base of the spark plug to keep dirt out of the engine u pon re­ moval. Remove the spark plug and check its condi­ tion.
  • Page 78 Figure Worn. 8-1 2 . Worn : On a worn plug . the center electrode will Figure Normal. 8-1 0. be rounded and the gap will be eroded . 0 1 0 " or Normal: more beyond the correct gap . Replace a worn A plug taken from an engine operating spark plug .
  • Page 79 device is intended for battery charging and light­ ing . Refer to the wiring diagrams and troubleshooting g uides in this subsection to test and service these systems. There are no adjustments in these sys­ tem s . Replace if faulty. NOT E : To prevent damage to the electrical system and components: Make sure the battery polarity i s correct .
  • Page 80 Tro ubleshooting Guide 1 .25 Amp Or Amp Unreg ulated Charging System Optional 70 Watt Lighting NOTE : Zero ohmmeters and voltmeters on each scale to ensure accurate readings . Voltage test should be made with engine running at 3000 RPM -no load. Battery m ust be fully charged . Test Conclusion Problem...
  • Page 81 Electric Start Engines 1 . 25 Amp Or Amp Unregulated Battery Charging System Optional 70 Watt Lig hting Diode (Blue) Spark P l u g G ND (Red) B reaker Flywheel Points Stator (Black) Optional 7 0 Wa r - - - - - - , Lighting Stator (Yellow) Con d e n s e r...
  • Page 82 TROUBLE ANALYSIS 1 0 AMP ALTERNATOR SYSTEM TEST WITH ENGINE RUNNING AT RPM - NO LOAD 3600 CONDITION: No Charge To Battery Possible Fault/Remedy TEST A -- Disconnect B+ cable to positive terminal of batte ry . Connect DC Voltmeter between B+ cable and ground .
  • Page 83 Electric Start Engines 1 5 Amp Regu lated Battery Charging System St arter Regulator Volt B attery Flywheel Alternator Keyswitch Ammeter B reaker Poi n t s Co n d e n s e r Coi l Fig u re 8 - 1 6 . Wiring Diagra m - Electric Start Engines/ 1 5 Amp Reg ulated Battery Charg i n g System. Rectifier- Regulator Fig u re 8- 1 7.
  • Page 84 Troubleshooting G uide 1 5 Amp Battery Charging System NOTE : Zero ohmmeters and voltmeters on each scale to ensure accurate readings. Voltage tests should be made with engine running at 3600 RPM no loa d . Battery must be fully charged . Problem Test Conclusion...
  • Page 85 El ectric Start Engine 25 A m p Regu lated Battery Charging System Starter I:rC. 12 Vol t Reg ulator Battery Flywheel Alt ernator A m m eter Breaker Poi n t s Cond e n s e r Coil Figu re 8-1 8.
  • Page 86 Trou bleshooting Guide 25 Amp Battery Charging System " NOTE : Zero ohmmeters and voltmeters on each scale to ensure accurate readings . Voltage tests should be made with engine running at 3600 RPM no load . Battery must be fully charged . Problem Test Conclusion...
  • Page 87 Electric Start Engine Amp Regulated Battery Charging System 1 2 Volt Battery Regulator Lights Breaker Points �� � (Key Start) Coli Condenser Figure 8-20. Wiri n g Diagra m - Electric Start Engines/3D Amp Regulated Battery Charg i n g System. Full Wave Rectifier Black...
  • Page 88 Troubleshooting Guide 30 Amp Regulated Battery Charging System Output tests should be made with engine running at 3600 RPM - no load . Battery must be fully charged . Problem Test Conclusion Remove 4 Input leads from rectifier-regulator. Set ohmmeter on Rx1 scale and zero scale . 1 a .
  • Page 89 SAFETY INTERLOCK CIRCUIT ON VEHICLE SEAT SMALL TERMINAL ---- -.,.: JUMPER (TEST ONLY) SOLENOID BATTERY Figure 8-22 . Battery Ignition I nterlock Bypass. � WARNING: Brush Replacement Never return an engine to the (Refer to Figure 8-23. ) owner with the safety interlock system removed or bypassed.
  • Page 90 Reinstall the brush holder and new stud termi­ nal with positive (+) brushes into end cap . Commutator Secure with the fiber washer, plain washer, End Cap split lock washer, and hex nut. CAUTION : To prevent electric arcing, make sure the stud terminal and braided brush leads do not touch the end cap .
  • Page 91 DUST SHI ELD (OPEN END TYPE) DUST SHI ELD (CUp TYPE) SHI ELD . . 1.: ;.' - - - " DRI VE " PIN ION " (FRO M K IT) " " (DISCARD 1 2 0 INCH LBS . ORIGINAL ) Figure Bendix Drive Installation.
  • Page 92 5 / 1 6 " , replace them . everything clean and apply a very thin coat of special silicone grease (Kohler Part No . 52 357 Remove the negative brush by drilling out the 0 1 ) to the splined portion of the armature rivet holding it to the end cap .
  • Page 93 Service the permanent magnet starter as follows . bracket and frame off of the drive end of the Refer to Figure 8-29 . armature. Remove the stop nut and the remainder of the Separate the end cap from the armature , be­ Bendix d rive.
  • Page 94 The starter bendix drive used by Kohler is de­ signed and manufactured to withstand forces far in When disconnecting battery cables, always discon­ excess of those required for normal operation nect the negative (--) cable first.
  • Page 95 SECTION 9 AUTOMATIC COMPRESSION RELEASE All K-Series single cylinde r engines , except the results in an effective compression ratio of about 2: 1 d u ring cranking . K9 1 , are equi pped with Automatic Compression Release (ACR) . The ACR mechanism lowers com­ After the engine speed increases to about 600 pression at cranking speeds to m ake starting eas­...
  • Page 96 • COM PRESSION TESTING Manual starting (rope start or retractable start) is much easier. Without ACR , manual starting at Because of the ACR mechanism , it is difficult to full compression would be virtually impossible . obtain an accurate compression reading . •...
  • Page 97 NOTE : Caution must down carefully to within the .03 1 . 042 rang e . of the tab as i t is hardened and may crack or If t h e valve lift was below . 03 1 , remove t h e break i f bent back and forth more than 3 or 4 camshaft cover o n the s i d e of the e n g i n e ex­...
  • Page 98 SECTION 1 0 D ISASSEM B L Y 9 . Remove electric starter. WARNING: Accidental Starts 1 0 . Remove fuel tank . Before servicing the engine or equi pment, always 1 1 . Remove d ipstick. remove the spark plug lead to prevent the engine 1 2 .
  • Page 99 REMOVE THROrrLE LIN KAGE AND Disconnect the fuel line from the fuel pump outlet fitting . Refer to Figure 1 0- 1 . CARBURETOR � WARNING: Explosive Fuell Gasoline may be present in the carburetor and fuel system. Gasoline is extremely flammable and it can explode if ignited.
  • Page 100 Rope Start Models Remove the carburetor side air baffle. Remove the g rass screen retainer and wire Remove the starter side air baffle. mesh grass screen from rope pulley. REMOVE BREATH ER ASSEM BLY Hold the flywheel with a strap wrench and loosen the hex cap screw.
  • Page 101 screws could cause the magnet to come off d ur­ REMOVE CONNECTING ROD A N D PISTON ing engine operation and be thrown from the en­ gine causing severe inj u ry . Replace the flywheel if Remove the connecting rod cap . Refer to magnet is damaged .
  • Page 102 NOT E : If the repair does not require separating the bearing plate from crankshaft . the crankshaft and Center Compression Ring bearing plate can be pressed out as a n assembly. Top Compression Ring REMOVE CAMS HAFT AND TAPPETS Drive the camshaft pin (and cup plug on bear­...
  • Page 103 Co.pper Washer Fig u r e 1 0- 1 0. Removing Tappets. Figure 1 0-1 2. Removing Cross Shaft And Stop Pin. NOTE : The intake valve tappet is closest to the bearing plate side of crankcase . The exhaust valve tappet is closest to the PTa side of crankcase .
  • Page 104 Apply Slight aged . Downward Inspect ring gear for cracks or damage. Kohler no longer provides ring gears as a serviceable part. Replace flywheel if the ring gear is damaged . FLYWHEEL K EY...
  • Page 105 CYLINDER BLOCK finish stones ( 220-280 grit) and polish to final size . A crosshatch should be observed if hon­ Inspection and Recond itioning ing is done correctly. The crosshatch should intersect at approximately 23 0-330 off the Check all gasket surfaces to make sure they are horizontal .
  • Page 106 Measuring Piston-to-Bore Cleara nce Use an inside micrometer, telescoping gauge , or bore gauge and measure the cylinder bore . Before i nstal ling the piston i nto the cylinder bore , it Take the measurement approximately 2- 1 /2 " is necessary that the clearance be accurately below the top of the bore and perpendicular to checked .
  • Page 107 M odel K241 , DIMENSION K321 , K341 Model K9 1 Model K 1 6 1 , K 1 8 1 (SEE FIG. 1 1 -5) I ntake Exhaust Intake Exhaust Intake Exhaust ° ° ° ° ° 89 ° A S EAT ANGLE B SEAT WIDTH .
  • Page 108 Excessive build up of deposits in the Carbon Cut: Leaka g e : A poor grind on face or seat of valve will combustion chamber may result in valve damage allow leakage resulting in a b urned valve on one because deposits can become hard enough to cut side only.

  • Page 109: Valve Guides

    Fig u re 1 1 -6 . Pulling Valve G u i d e . area , use only Kohler service replacement inserts , which are slightly larger to provide proper retention 1 .
  • Page 110 Remove Valve Seal Insert NOTE : Make sure sharp lip on puller (see insert) engages in joint between bottom of valve seat in­ To remove a valve seat insert , refer to Figure sert and cylinder block counterbore, all the way 1 1 -8 and proceed as follows : around .
  • Page 111 These pistons are available from Kohler. Standard Service Rings should be used with both Standard and . 003 " oversize pistons . Ring end gap will increase slightly when installed on .
  • Page 112 takes on a shiny or bright appearance . Scratches deposits , blocked fins , improperly seated valves or on rings and piston are caused by abrasive mate­ wrong spark park plug . rial such as carbon , dirt , or pieces of hard metal . See Figure 1 1 - 1 0 for some common types of pis­...

  • Page 113: Install Piston Rings

    Some important points to remember when servic­ ing piston rings : If the cylinder block does not need reboring and if the old piston is within wear l imits (refer to Section 1 , General Information " ) and free of score or scuff marks , the old piston may be reused .

  • Page 114: Inspection And Repair

    G EAR ASSEMBLY A new needle bearing for the Dynamic Balance System is now being used o n 1 0-1 6 H P Kohler engines. The new bearing (part n umber 47030 0 1 ) has been in use beginning with serial n umber...
  • Page 115 .735" 1 1 / 1 6 " 1 - 1 / 1 6 " NOMINAL - NOMI NAL - � 1 . 1 1 0" PRESS DEPTH PRESS DEPTH STU' SHAn STUB SHAFT /3/8" ABOVE MAIN SPACER STUB SHAFT BEARING BOSS BOSS 7/16"...
  • Page 116 SHAFT END - GEAR HUB D I ME N S I O N K91 - - . 7 40- . 750" K 1 4 1 - - 1 . 1 05 - 1 . 1 1 5 " K 1 6 1 - - 1 . 1 05 - 1 . 1 1 5 "...
  • Page 117 Installation the cover oil seal . Install the gasket(s) and reduction gear cover and tighten cap screws . Wrap piece of tape or roll paper around crank­ Adjust shaft end clearance t o . 00 1 / . 006 inches shaft gear to protect the oil seal , slide housing by varying the total gasket thickness, adding over the shaft and attach to the block.
  • Page 118 SECTION 1 2 REASSEM BLY The following sequence is suggested for complete I NSTALL REAR BEARING engine reassembly. This procedure assumes that all components are new or have been recondi­ Install the rear bearing into crankcase using tioned , and all component subassembly work has the #4747 handle and appropriate bearing in­...
  • Page 119 NOTE : O n K 1 6 1 and K1 8 1 ACR engi nes , install the shorter tappet in the exhaust bore guide . Intake and exhaust tappets are interchangeable on other models . I nstall the camshaft , one . 005 " shim spacer , and the camshaft pin (from bearing plate side) .
  • Page 120 To install the old (longer) camshaft pin, drive the * Balance gear spacer kit , Kohler Part 47 755 0 1 , contains enough 3/8 " , . 005 " , . 0 1 0 " , a n d . 0 2 0 "...
  • Page 121 ance gear assemblies (Part N o . 45 043 03) are being used in engines with a Serial No. of 1 6 1 36000 1 3 and later, and for service replace­ ment . Figure 1 2- 1 2 shows the physical differences between the old and new style gear assemblies .
  • Page 122 OLD STYLE BALANCE GEAR ASSEM BLY - Remove the balance gear timing tool and WITH A BALANCE GEAR T I M I NG TOOL align the primary timing mark on the crank­ shaft with the timing mark o n the camshaft Align t h e primary timing marks of balance gear.
  • Page 123 NOTE : The lower balance gear should be installed play o f lower balance gear a s instructed u nder after the crankshaft has been installed . " INSTALL BALANCE GEARS . " Refer to Figures 1 2-9 and 1 2- 1 0 . Lubricate the crankshaft rear bearing surfac e .
  • Page 124 Press the crankshaft into the rear bearing until the crankshaft gear is j ust above the camshaft gear, but not in mesh with it. Do not remove t h e balance g ea r t i m i n g tool at t h i s time. 4 .
  • Page 125 If the marks do not a l ig n , the timing is incorrect and must be corrected . Figure 1 2- 2 6 . Marking Land O n U pper Balance Gear. Figure 1 2- 2 4 . Cra nkshaft Gear/Ca mshaft Gear Alignment.
  • Page 126 Figure 1 2-30. Crankshaft Gear/Lower Balance Gear Alignment. Fig u re 1 2-28. Aligning Camshaft Gea r And Crankshaft Gear. Check the timing of the crankshaft , camshaft , and balance gears : • The pri mary timing mark on crankshaft Install the 3 / 8 "...
  • Page 127 INSTALL FUEL LIN E AND WIRING case and bearing plate . Check the end play after the bearing plate is installed . HARNESS Position the fuel line and wiring harness (if so Install two hex cap sems screws and hand equipped) to crankcase .
  • Page 128 SLEEVE BEARING FLYWHEEL MAGNETO BREAKERLESS BATTERY (TYPICAL ) (TYPICAL) ( TYPICAL) (TYPICAL) SEAL DEPTH - 8--i- --i- - S EAL DEPTH PRESS SEAL AGAINST SHOULDER Fig ure 1 2-34. Front Oil Seal Location. I N STALL OIL S EALS Orient piston and con necting rod so that the Slide the appropriate seal sleeves over the crankshaft (refer to the "...
  • Page 129 Oil Hole Figure 1 2-37. I nstalling Con necting Rod Cap . Torque t h e capscrew t o 20% over t h e nominal Figure 1 2-36. I nsta l l i n g Pistons. torque value listed below . Loosen cap screws to below the nominal value--do not l eave Orient the notch (on Style C"...
  • Page 130 I N STALL VALVES Model Intake Valve Exhaust Valve K9 1 . 005" / . 009 " . 0 1 1 " / . 0 1 5 " Rotate the crankshaft u ntil piston is at top K 1 6 1 , K 1 8 1 .
  • Page 131 Permanent magnets are af­ Figure 1 2-40. Installing Valves - K91 , K 1 6 1 fixed to the inside rim of the flywheel except in A n d K 1 8 1 .
  • Page 132 1 2-43. Installing A Square Flywheel Key. nut and crack the flywheel hUb. Models K91 , K 1 S1 And K 1 a1 Rope Start Models D o not reuse a flywheel if i t h a s been d ropped Install rope pulley, plain washer, and hex n ut or damag ed in any way.
  • Page 133 Models K241 , K301 , K321 And K341 INSTALL CYLINDER H EA D AND S PARK PLUG Rope Start Install the gasket and cylinder head . Always A . Install the nylon g rass screen . use a new gasket when head has been re­ moved for service work .
  • Page 134 � K161, K1 8 1 Figure 1 2-45. K 1 8 1 B reat h e r Assembly. 15-20 ft. Ibs. CLOSED BREATHER PLATE BREATHER " PLATE SEAL GASKET VALVE COVER © REED COVER GASKET , K241, � K301, K321 STUD ( IN CRANKCASE ) 25-30 ft.
  • Page 135 INSTALL DI PSTICK NOTE: Make sure the fuel pump lever is positioned above the camshaft . Damage to the fuel pump, Install dipstick. and subsequent severe engine damage could re­ sult if the lever is positioned below the camshaft . INSTALL FUEL TANK Refer to Figure 1 2-48 .

  • Page 136: Governor Adjustment

    Governor Adjustment PREPARE THE E N G I N E FOR OPERATION The governor cross shaft/governor arm must be adjusted The engine i s now completely reassemb led. Before every time the governor arm is loosened or removed starting or operating the engine, be sure to do the from cross shaft.
  • Page 137 FOR SALES AND SERVICE INFORMATION IN U . S . AND CANADA, CALL 1 -800-544-2444 This publication replaces ENS-575 FORM NO.: TP-2379 ISSUED: 4/ 90 REVISED: 1 1 /92 MAILED: ENG I NE DIVISION, KOHLER CO ., KOHLER, WISCONSIN 53044 LITHO IN U.S.A.

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