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CV682, CV732, CV742, CV752 Service Manual

Contents

1. 20 SPARKPLUGREMOVAL 246 12 FUEL 19 690 FILTER 253 35 SPARKPLUG 9 974 BOOT 2753 SPARK PLUG REMOVAL 1 084 REMOVAL SPARK PLUG BOOT f i Q CRANKSHAFT 52 02 m 2 048 SPARK PLUG BOOT REMOVAL 1 10 145 19 MOUNTING q Nane 0 618 5 716 HOLE A OIL FILTER REMOVAL FLYWHEEL SIDE 1 1 367 34 14 462 316 96 12 479 i His 1 0511 OIL DRAIN PLUG 3 8 NPT INCH STARTER SIDE ENGINE MOUNTING SURFACE 20 781 246 12 12 867 19 690 SPARKPLUGREMOVAL SPARKPLUG 217 BOOT 10 896 REMOVAL SPARK PLUG BOOT 253 35 19 974 52 02 SPARK PLUG 1208 REMOVAL SPARK PLUG BOOT REMOVAL 33467 4 113 176 a 2X89 80 AN okre 3536 3 052 DIPSTICKTUBE ana 12 868 M8X1 25 4STUDS L ox 50 00 11369 EXHAUST PORT 2 P f MOUNTING HOLES 30 i i 50 00 11 969 EXHAUST PORT 1 2X 104 03 MOUNTING OM Le N i 14 096 HOLES HO 2022 29 V 19 539 2X89 80 3 536 SOLENOID SHIFT STARTER 4X09 20 0 362 THRU MOUNTING HOLE A Apion RC ENGINE MOUNTING SURFACE i PTO END 34534 Jon 113 596 154 04 6 065 316 4 SPARK PLUG T 112 458 OIL COOLER 505 67 119 908 PULSE FUEL PUMP X REGULATOR RECTIFIER 134 04 5 277 SPARK PLUG 5125 Ros OIL FILTER 12 99 nog osm
2. Governor Bore I D New 80 000 82 988 83 013 mm 80 025 mm 3 2672 3 2682 in 3 1496 3 1506 in Max Wear Limit 80 065 mm 83 051 mm 3 1522 in 3 2697 in Max Out of Round 0 12 mm 0 0047 in Max Taper 0 05 mm 0 0020 in Cylinder Head Max Out of Flatness 0 076 mm 0 1 mm 0 004 in 0 003 in Governor Cross Shaft to Crankcase Running Clearance 0 025 0 126 mm 0 0009 0 0049 in Cross Shaft O D New Max Wear Limit Governor Gear Shaft to Governor Gear Running Clearance Gear Shaft O D New Max Wear Limit 7 949 8 000 mm 0 3129 0 3149 in 7 936 mm 0 3124 in 0 015 0 140 mm 0 0006 0 0055 in 5 990 6 000 mm 0 2358 0 2362 in 5 977 mm 0 2353 in Ignition Spark Plug Gap 0 76 mm 0 030 in Module Air Gap 0 203 0 305 mm 0 008 0 012 in 3Values are in Metric units Values in parentheses are English equivalents 24 690 37 Rev B KohlerEngines com Specifications CLEARANCE SPECIFICATIONS CV682 CV732 CV742 CV752 Piston Piston Rings and Piston Pin Piston to Piston Pin Running Clearance 0 006 0 017 mm 0 0002 0 0007 in Max Wear Limit Pin Bore I D New 17 006 17 012 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in Pin O D New 16 995 17 000 mm 0 6691 0 6693 in 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance 0 030 0 070 mm 0 001 0 0026 in Middle Compressio
3. Remove Ignition Modules 1 Disconnect lead from each ignition module 2 Rotate flywheel so magnet is away from modules 3 Remove mounting screws and ignition modules Note position of ignition modules Remove Spark Plugs Remove spark plug from each cylinder head KohlerEngines com 43 Disassembly Inspection and Service Cylinder Head Components Remove Cylinder Heads and Hydraulic Lifters A Valves B Cylinder Head C Spark Plug D Nut E Hydraulic Lifter F Cap G Valve Stem Seal H Valve Spring Keeper I Valve Spring J en K Rocker Arm Pivot L Push Rod M Rocker Arm N Screw o Valve Cover O ring P Grommet Q Valve Cover R Gasket NOTE Cylinder heads are retained using either screws or nuts and washers on studs Do not interchange or mix components as cylinder heads may have different machining unique to each fastening method Remove screws or nuts and washers securing each cylinder head Unless screws are damaged or questionable they can be reused Discard nuts and washers once removed do not reuse Studs if present should only be removed if damaged or if cylinder reconditioning is necessary Once removed they must be replaced Mark location of push rods as either intake or exhaust and cylinder 1 or 2 Push rods should always be reinstalled 1 44 in same positions Carefully remove push rods cylinder heads and head gaskets Remove lifters from lifter bores
4. disassembling carburetor 1 Make sure fuel tank is filled with clean fresh gasoline 2 Make sure fuel tank cap vent is not blocked and that it is operating properly condition securely fastened to engine using gaskets in good 5 Make sure air cleaner element including precleaner if equipped is clean and all air cleaner components are fastened securely Make sure ignition system governor system exhaust system and throttle and choke controls are operating properly 3 Make sure fuel is reaching carburetor This includes checking fuel shut off valve fuel tank filter screen in line fuel filter fuel lines and fuel pump for restrictions or faulty components as necessary Troubleshooting Carburetor Related Causes Condition Possible Cause Conclusion Engine starts hard runs rough or stalls at idle speed Low idle speed improperly adjusted Adjust idle speed governed idle tab Engine runs rich indicated by black sooty exhaust smoke misfiring loss of speed and power governor hunting or excessive throttle opening Clogged air cleaner Choke partially closed during operation Float level is set too high Dirt under fuel inlet needle Bowl vent or air bleeds plugged Clean or replace air cleaner Check choke lever linkage to ensure choke is operating properly Adjust float according to Float Replacement Procedure Remove needle clean needle and seat and blow
5. 3 8 16 47 5 35 67 8 50 3 8 24 54 2 40 81 4 60 7 16 14 47 5 35 74 6 55 108 5 80 7 16 20 61 0 45 101 7 75 142 5 105 1 2 13 67 8 50 108 5 80 155 9 115 1 2 20 94 9 70 142 4 105 223 7 165 9 16 12 101 7 75 169 5 125 237 3 175 9 16 18 135 6 100 223 7 165 311 9 230 5 8 11 149 5 110 244 1 180 352 6 260 5 8 18 189 8 140 311 9 230 447 5 330 3 4 10 199 3 147 332 2 245 474 6 350 3 4 16 271 2 200 440 7 325 637 3 470 Metric Fastener Torgue Recommendations for Standard Applications Property Class Noncritical Size es Alona Tightening Torque N m in Ib 10 M4 1 2 11 7 15 2 9 26 4 1 36 5 0 44 2 0 18 M5 2 5 22 2 28 5 8 51 8 1 72 86 4 0 35 M6 4 3 38 7 50 9 9 88 14 0 124 46 6 8 60 M8 10 5 93 6 120 24 4 216 33 9 300 40 7 360 17 0 150 Tightening Torque N m ft Ib 10 M10 21 7 16 27 1 20 47 5 35 66 4 49 81 4 60 33 9 25 M12 36 6 27 47 5 35 82 7 61 116 6 86 139 7 103 61 0 45 M14 58 3 43 76 4 56 131 5 97 184 4 136 219 7 162 94 9 70 Torque Conversions N m in Ib x 0 113 N m ft Ib x 1 356 in Ib N m x 8 85 ft Ib N m x 0 737 12 KohlerEngines com 24 690 37 Rev B Tools and Aids Certain quality tools are designed to help you perform specific disassembly repair and reassembly procedures By
6. CARBURETOR A WARNING running Wy Explosive Fuel can cause fires and severe burns PAR f 2 Do not fill fuel tank while engine is hot or 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 Walbro Two Barrel Carburetor Components 22 KohlerEngines com Carburetor Body Float Valve Inlet A Subassembly B Vacuum Hose Needle Float Bowl Gasket F as G ne Bowl Screw Fuel Solenoid Solenoid Gasket Accelerator Accelerator Slow Jet K Pump Cover L Spring Diaphragm Screws Pump Cover Right Side Main Nozzle Plastic Dust Seal P Right Side Q Float Pin Idle Spring as P ea Choke Spring U Choke Shaft ee ne Choke Plate 24 690 37 Rev B Fuel System Engines in this series are equipped with a two barrel side draft carburetor with fixed main jets on a matching intake manifold Carburetor features a self relieving choke serviceable slow jets main jets accelerator pump and a fuel shutdown solenoid Troubleshooting Checklist 4 Make sure air cleaner base and carburetor are When engine starts hard runs roughly or stalls at low idle speed check following areas before adjusting or
7. 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 Puller SE Tools KLR 82408 For properly removing flywheel from engine 24 690 37 Rev B KohlerEngines com 13 Tools and Aids TOOLS Description Source Part No Hydraulic Valve Lifter Tool For removing and installing hydraulic lifters Kohler 25 761 38 S Ignition System Tester For testing output on all systems including CD Kohler 25 455 01 S Inductive Tachometer Digital For checking operating speed RPM of an engine Design Technology Inc DTI 110 Offset Wrench K and M Series For removing and reinstalling cylinder
8. Every 250 Hours e Replace air cleaner element and check inner element Air Cleaner Intake Every 500 Hours e Replace air cleaner inner element Air Cleaner Intake e Replace spark plugs and set gap Electrical System Every 500 Hours e Have crankshaft spline lubricated 1 Perform these procedures more frequently under severe dusty dirty conditions 2 Have a Kohler authorized dealer perform this service 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 24 690 37 Rev B KohlerEngines com S and Canada 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 F 20 0 20 32 40 50 60 80 100 C 30 20 10 0 10 20 30 40 FUEL RECOMMENDATIONS A WARNING Explosive Fuel can cause fires and severe 3 burns 4 4 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 sp
9. Perform removal procedures for appropriate air cleaner and carburetor outlined in Disassembly Clean exterior surfaces of dirt or foreign material before disassembling carburetor Disconnect accelerator pump vacuum hose from bottom of bowl Remove screws and carefully separate fuel bowl from carburetor Transfer any remaining fuel into an approved container Discard bowl screws and gasket save other parts Remove float pin lift out float and inlet needle discard parts Seat for inlet needle is not serviceable and should not be removed Use a 1 4 open end wrench and carefully remove nozzle tubes from bowl Note and mark jets by location for proper reassembly Main jets and main nozzles may be size side specific Main jets are pressed into bottom of main nozzle tubes and are not serviced separately Slow jets are located to outside of nozzle tubes and are removed with a narrow straight blade screwdriver Save parts for cleaning and reuse Remove accelerator pump cover screws from bottom of bowl while holding pump cover in place Accelerator pump spring will be pushing against cover as it is directly under it Remove and discard spring and diaphragm Solenoid can also be removed using a 1 2 wrench and gasket discarded Carburetor is now disassembled for appropriate cleaning and installation of parts in overhaul kit Further disassembly is not necessary Throttle shaft assembly fuel inlet seat idle fuel adjustment screws are non
10. TORQUE SPECIFICATIONS CV682 CV732 CV742 CV752 Blower Housing and Sheet Metal M5 Fasteners 6 2 N m 55 in Ib into new holes 4 0 N m 35 in Ib into used holes M6 Fasteners 1 0 7 N m 95 in Ib into new holes 65 in Ib into used holes N w z 3 Carburetor Intake Manifold and Air Cleaner Intake Manifold to Head Mounting Fastener torgue in 2 increments first to 7 4 N m 66 in Ib finally to 9 9 N m 88 in Ib Air Cleaner Nut torque in 2 increments first to 7 3 N m 65 in Ib finally to 8 2 N m 73 in Ib Support Bracket to Intake Manifold Fastener 9 9 N m 88 in lb Support Bracket to Air Cleaner Housing Fastener 7 9 N m 70 in lb Evap Connector Fitting to Air Cleaner Housing HI LO Fastener if equipped 2 1 N m 19 in Ib Connecting Rod Cap Fastener torque in increments 13 6 N m 120 in Ib Crankcase Breather Cover Fastener 7 3 N m 65 in Ib Oil Drain Plug 13 6 N m 10 ft Ib 3Values are in Metric units Values in parentheses are English equivalents 4 Exceeding maximum angle of operation may cause engine damage from insufficient lubrication 5 Lubricate threads with engine oil prior to assembly 6 Any and all horsepower hp references by Kohler are Certified Power Ratings and per SAE J1940 amp J1995 hp standards Details on Certified Power Ratings can be found at KohlerEngines com 6 KohlerEngines
11. ENGINE MOUNTING SURFACE ta Ha S MOUNTING HOLE 199 59 13 160 14314 En OIL FILTER OIL DRAIN PLUG 3 8 NPT INCH 1VAIN SOKEVWAY 52856 7 16 20 UNF 28 INCH 11 125 38 1 1 500 OIL FILTER SIDE Su ean Dimensions in millimeters H 13 925 4 a eh Inch equivalents shown in 9 503 4 N SAFETY AR FILTER ns ma BEE E PENAT AOIN J B 664 110 726 63s 5 118 AIR FILTER AIR FILTER COVER RAIN CAP ASSEMBLY REMOVAL REMOVAL VALVECOVER 24 690 37 Rev B KohlerEngines com Specifications ENGINE IDENTIFICATION NUMBERS Kohler engine identification numbers model specification and serial should be referenced for efficient repair ordering correct parts and engine replacement Model 2 eee eee CV68 Command Engine Vertical Shaft Numerical Designation Specification CV682 0001 Seral oa da He 4323500328 Year Manufactured Code Factory Code Code Year 43 2013 44 2014 45 2015 GENERAL SPECIFICATIONS CV682 CV732 CV742 CV752 Bore 80 mm 83 mm 3 27 in 3 15 in Stroke 69 mm 2 72 in Displacement 694 cc 747 cc 45 6 cu in 42 4 cu in Oil Capacity refill 1 6 1 8 L 1 7 1 9 U S qt Maximum Angle of Operation full oil level 25
12. printing up 5 Install cylinder head Match numbers on cylinder heads and crankcase Make sure head is flat on gasket and dowel pins 6 Lightly lubricate exposed upper threads of studs with engine oil Install a new flat washer and nut onto each mounting stud Torque nuts in two stages first to 16 9 N m 150 in Ib then finally to 35 5 N m 315 in Ib following sequence shown 24 690 37 Rev B Install Push Rods and Rocker Arms NOTE Push rods should always be installed in same position as before disassembly 1 Note mark or tag identifying push rod as either intake or exhaust and cylinder 1 or 2 Dip ends of push rods in engine oil and install making sure that each push rod ball seats in its hydraulic lifter socket 2 Apply grease to contact surfaces of rocker arms and rocker arm pivots Install rocker arms and rocker arm pivots on one cylinder head and start screws 3 Torque screws to 18 1 N m 160 in Ib 4 Use a spanner wrench or rocker arm lifting tool to lift rocker arms and position push rods underneath 5 Repeat above steps for remaining cylinder Do not interchange parts from cylinder heads 6 Rotate crankshaft to check for free operation of valve train Check clearance between valve spring coils at full lift Minimum allowable clearance is 0 25 mm 0 010 in Check Assembly Rotate crankshaft a minimum of two revolutions to check long block assembly and overall proper operation
13. 050 0 088 mm 0 0020 0 0035 in Intake Valve Guide I D New Max Wear Limit 7 038 7 058 mm 0 2771 0 2779 in 7 134 mm 0 2809 in Exhaust Valve Guide I D New Max Wear Limit 7 038 7 058 mm 0 2771 0 2779 in 7 159 mm 0 2819 in Valve Guide Reamer Size Standard 0 25 mm O S 7 048 mm 0 2775 in 7 298 mm 0 2873 in Intake Valve Minimum Lift 8 07 mm 0 3177 in Exhaust Valve Minimum Lift 8 07 mm 0 3177 in Nominal Valve Seat Angle 45 3Values are in Metric units Values in parentheses are English equivalents 24 690 37 Rev B KohlerEngines com 11 Specifications GENERAL TORQUE VALUES English Fastener Torque Recommendations for Standard Applications Bolts Screws Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners amp Into Aluminum Size Grade 2 Grade 5 Grade 8 O Tightening Torque N m in Ib 20 8 32 2 3 20 2 8 25 2 3 20 10 24 3 6 32 4 5 40 3 6 32 10 32 3 6 32 4 5 40 1 4 20 7 9 70 13 0 115 18 7 165 7 9 70 1 4 28 9 6 85 15 8 140 22 6 200 5 16 18 17 0 150 28 3 250 39 6 350 17 0 150 5 16 24 18 7 165 30 5 270 3 8 16 29 4 260 3 8 24 33 9 300 Tightening Torque N m ft Ib 20 5 16 24 40 7 30
14. 1 3138 1 3240 in 29 37 29 63 mm 1 1563 1 1665 in F Valve Face Angle 45 45 G Valve Margin Min 1 5 mm 0 0591 in 1 5 mm 0 0591 in H Valve Stem Diameter 6 982 7 000 mm 0 2749 0 2756 in 6 970 6 988 mm 0 2744 0 2751 in 24 690 37 Rev B KohlerEngines com 45 Disassembly Inspection and Service After cleaning check flatness of cylinder head and corresponding top surface of crankcase using a surface plate or piece of glass and feeler gauge Maximum allowable out of flatness is 0 076 mm 0 003 in for 80 mm bore 0 1 mm 0 004 in for 83 mm bore Carefully inspect valve mechanism parts Inspect valve springs and related hardware for excessive wear or distortion Check valves and valve seat area or inserts for evidence of deep pitting cracks or distortion Check clearance of valve stems in 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 burnt valve faces or seats loss of compression and excessive
15. F 0 C 200 cca minimum O F to 32 F 18 C to 0 C 250 cca minimum 5 F to O F 21 C to 18 C 300 cca minimum 10 F 23 C or below 400 cca minimum 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 24 690 37 Rev B KohlerEngines com 31 Electrical System Wiring Diagram 15 20 25 Amp Regulated Battery Charging System 32 KohlerEngines com 24 690 37 Rev B Electrical System Ignition Systems These systems use a capacitive discharge CD coil With CDI fixed timing 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 MDI adjustable timing uses a digital microprocessor which is located in ignition modules Ignition timing varies depending upon e
16. and ground spark plug lead s before servicing Kor Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery NOTE Main and slow jets are fixed and size specific and can be removed if required Fixed jets for high altitudes are available NOTE Keep solvent away from plastic or rubber parts if non compatible or damage may occur 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 Float Replacement Overhaul Choke Repair Float Setting pei MD a ire en Int a A Top of Float Body Carburetor Body Inverted B Top of Gasket Crush Ribs 1 6 mm 0 063 in 0 5 mm 0 02 in Float Setting NOTE Inlet needle center pin is spring loaded Make sure float rests against fuel inlet needle without depressing center pin If symptoms described in Troubleshooting Carburetor Related Causes indicate float level problems remove carburetor from engine to check and or replace float Use a float kit to replace float pin float valve 24 690 37 Rev B 11 12 13 Fuel System
17. com 24 690 37 Rev B TORQUE SPECIFICATIONS Specifications CV682 CV732 CV742 CV752 Cylinder Head Fastener torque in 2 increments Nut first to 16 9 N m 150 in Ib finally to 35 5 N m 315 in Ib Bolt torque in 2 increments first to 22 6 N m 200 in Ib finally to 41 8 N m 370 in Ib Rocker Arm Screw 18 1 N m 160 in Ib Flywheel Fan Fastener 9 9 N m 88 in Ib Flywheel Retaining Screw 66 4 N m 49 ft Ib Fuel Pump Pulse Fastener 2 3 N m 20 in Ib Governor Lever Nut 6 8 N m 60 in Ib Ignition Spark Plug 27 N m 20 ft Ib Module Fastener 4 0 6 2 N m 35 55 in Ib Rectifier Regulator Fastener 1 4 N m 12 6 in Ib Muffler Retaining Nut 24 4 N m 216 in Ib Oil Cooler Adapter Nipple 27 N m 20 ft Ib Oil Pan Fastener 24 4 N m 216 in Ib Oil Pump Screw no torque sequence 9 0 N m 80 in Ib Oil Sentry Pressure Switch 4 5 N m 40 in lb Solenoid Starter Mounting Hardware 4 0 6 0 N m 35 53 in Ib Nut Positive Brush Lead 8 0 11 0 N m 71 97 in Ib Speed Control Bracket Hi Lo Screw into Blower Housing 2 2 N m 19 in Ib Starter Assembly Thru Bolt 5 6 9 0 N m 49 79 in Ib Mounting Screw 15 3 N m 135 in lb Brush Holder M
18. completely 2 Clean area around oil filter Place a container under filter to catch any oil and remove filter Wipe off mounting surface a Reinstall drain plug Torque to 13 6 N m 10 ft Ib or b Close oil drain valve body remove hose if used and replace cap 3 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 4 Apply a thin film of clean oil to rubber gasket on new filter 5 Refer to instructions on oil filter for proper 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 OIL COOLER if equipped 1 Clean fins with a brush or compressed air 2 Remove screws securing oil cooler and tilt to clean back side 3 Reinstall oil cooler 24 690 37 Rev B 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 manuals for more information Oil Sentry pressure switch is installed in breather cover On engines not equipped
19. end gap 3 Top compression ring top groove Install top ring using a piston ring expander Make sure identification mark is up or colored dye stripe if contained is to left of end gap 24 690 37 Rev B Offset stepped cap connecting rods are used in all these engines Inspection and Service Check bearing area big end for excessive wear score marks running and side clearances refer to Specifications Replace rod and cap if scored or excessively worn Service replacement connecting rods are available in STD crankpin size and 0 25 mm 0 010 in undersize Undersized rods have an identification marking on lower end of rod shank Always refer to appropriate parts information to ensure correct replacements are used Remove Crankshaft Inspection and Service Crankshaft Components and Detail Flat Washer Crankshaft A Self Tapping Screw C Plug D EN Fillet Must Blend Smoothly with Bearing Journal Surface High Point from Fillet Intersections 45 Minimum o n m H This Fillet Area Must Be Completely Smooth NOTE If crankpin is reground visually check to insure fillet blends smoothly with crankpin surface NOTE To prevent repeat failures camshaft and crankshaft should always be replaced as a set Carefully pull crankshaft from crankcase KohlerEngines com 51 Disassembly Inspection and Service Inspect gear teeth of cra
20. even with lowest edge of bore start drill and honing process Move hone up and down while resizing to prevent formation of cutting ridges Check size frequently 3 When bore is within 0 064 mm 0 0025 in of desired size remove coarse stones and replace them with burnishing stones Continue with burnishing stones until bore is within 0 013 mm 0 0005 in of desired size and then use finish stones 220 280 grit and polish bore to its 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 and too steep an angle will result in high oil consumption 4 After resizing 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 3 locations in cylinder at top middle and bottom There are 2 measurements that should be taken perpendicular to each other at all 3 locations 24 690 37 Rev B Disassembly Inspection and Service Clean Cylinder Bore After Honing Proper cleaning of cylinder walls following boring and or honing is very critical to a successful overhaul Machining grit left in cylinder bore can destroy an engine in less than 1 hour of operation after a rebuild Final cleaning operation should always be a thorough scrubbing with a brush and hot soapy water Use a
21. flywheel and cranks engine When engine starts and start switch is released starter solenoid is deactivated drive lever moves back and drive pinion moves out of mesh with ring gear into retracted position Starter Disassembly NOTE Do not reuse old retainer 38 KohlerEngines com NOTE Do not soak armature or use solvent when cleaning Wipe clean using a soft cloth or use compressed air 1 Remove hex nut and disconnect positive brush lead bracket from solenoid terminal 2 Remove head screws securing solenoid to starter 3 If solenoid was mounted with Phillips head screws separate solenoid and plunger spring from drive end cap If solenoid was mounted with external Torx head screws plunger is part of solenoid unhook plunger pin from drive lever Remove gasket from recess in housing 4 Remove thru larger bolts 5 Remove commutator end plate assembly containing brush holder brushes springs and locking caps Remove thrust washer from inside commutator end 6 Remove frame from armature and drive end cap 7 Remove drive lever pivot bushing and backing plate from end cap 8 Take out drive lever and pull armature out of drive end cap 9 Remove thrust washer from armature shaft 10 Push stop collar down to expose retaining ring 11 Remove retainer from armature shaft Save stop collar 12 Remove drive pinion assembly from armature 13 Clean parts as required Inspection Check drive p
22. 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 42 KohlerEngines com 1 Remove screws securing throttle shaft bracket and governed idle bracket to cylinder head 2 Disconnect springs from governor lever note hole locations for reassembly 3 Remove choke linkage from choke lever and carburetor Reattach bushing to linkage following separation to avoid losing it 24 690 37 Rev B Remove Carburetor Disassembly Inspection and Service Remove Oil Sentry WARNING Explosive Fuel can cause fires and severe P burns lj 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 1 Disconnect fuel shut off solenoid lead 2 Remove throttle linkage and linkage spring from governor lever Reattach bushing to linkage following separation to avoid losing it 3 Remove carburetor throttle linkage and linkage spring as an assembly 4 Remove carburetor gasket 5 If necessary carb
23. lubricants Presence of lubricants can cause flywheel to be over stressed and damaged when screw is torqued to specifications NOTE Make sure flywheel key is installed properly in en keyway Flywheel can become cracked or damaged if key is not properly installed Install woodruff key into keyway of crankshaft Make sure key is properly seated and parallel with shaft taper Install flywheel onto crankshaft being careful not to shift woodruff key Install screw and washer Use a flywheel strap wrench or holding tool to hold flywheel Torque screw securing flywheel to crankshaft to 66 4 N m 49 ft Ib A Valves B Cylinder Head C Spark Plug D Nut E Hydraulic Lifter F Cap G Valve Stem Seal H Valve Spring Keeper I Valve Spring J k coun K Rocker Arm Pivot L Push Rod M Rocker Arm N Screw o Valve Cover O ring P Grommet Q Valve Cover R Gasket 24 690 37 Rev B KohlerEngines com 57 Reassembly Install Hydraulic Lifters NOTE Hydraulic lifters should always be installed in same position as before disassembly Exhaust lifters are located on output shaft oil pan side of engine while intake lifters are located on fan side of engine Cylinder numbers are embossed on top of crankcase and each cylinder head 1 Refer to Disassembly Inspection and Service for hydraulic bleeding lifter procedures 2 Apply camshaft lubricant to bottom surface of each lifter Lubricate hydraulic
24. oil consumption To check valve guide to valve stem clearance thoroughly clean valve guide and using a split ball gauge measure inside diameter of guide 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 by subtracting stem diameter from guide diameter 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 I D wear on intake valve guide is 7 134 mm 0 2809 in while 7 159 mm 0 2819 in is maximum allowed on exhaust guide Guides are not removable but can be reamed 0 25 mm 0 010 in oversize Valves with 0 25 mm oversize stems must then be used If guides are within limits but valve stems are worn beyond limits install new valves 46 KohlerEngines com Valve Seat Inserts Hardened steel alloy intake and exhaust valve seat inserts are press fitted into cylinder head Inserts are not replaceable but can be reconditioned if not too badly pitted or distorted If 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 Cutting proper 45 valve face angle as specified and
25. regulator knob clockwise increase direction until gauge needle is in yellow set area at low end of scale 8 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 Condition Conclusion Air escaping from crankcase breather Ring or cylinder worn Air escaping from exhaust system Defective exhaust valve improper seating Air escaping from intake Defective intake valve improper seating Gauge reading in low green zone Piston rings and cylinder in good condition 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 24 690 37 Rev B KohlerEngines com 19 Air Cleaner Intake AIR CLEANER These systems are CARB EPA certified and components should not be altered or modified in any way Air Cleaner Components A Air Cleaner Housing B End Cap C Element D Inner Element E Ejector Area F Inlet Screen G Retaining Clip H Filter Minder Optional or Plug NOTE Operating engine with loose or damaged air cleaner components could cause premature wear and failure Replace all bent or damaged components NOT
26. ring into groove in oil pan make sure it is fully seated in groove 4 Install oil pump inserting center shaft into corresponding recess in oil pan Apply consistent downward pressure to oil pump cover compressing oil pressure relief spring and start screws Secure oil pump by torquing screws in no specific sequence to 9 0 N m 80 in Ib 5 After torquing rotate gear and check for freedom of movement Make sure there is no binding If binding occurs loosen screws reposition pump retorque screws and recheck movement 24 690 37 Rev B Disassembly Inspection and Service Remove Camshaft Remove camshaft Inspection and Service NOTE To prevent repeat failures camshaft and crankshaft should always be replaced as a set Check lobes of camshaft for wear or damage See Specifications for minimum lift tolerance Inspect cam gear for badly worn chipped or missing teeth Replacement of camshaft will be necessary if any of these conditions exist Remove Governor Cross Shaft 1 Remove hitch pin and plain washer or retainer and nylon washer from governor cross shaft 2 Remove cross shaft through inside of crankcase Governor Cross Shaft Oil Seal A 2 0 mm 0 0787 in B Governor Cross Shaft Seal If governor cross shaft seal is damaged and or leaks replace it using following procedure Remove oil seal from crankcase and replace it with a new one Install new seal to depth shown using a
27. serviceable items and should not be removed Choke shaft assembly is serviceable however it should not be removed unless a choke repair kit will be installed To install choke repair kit go to step 7 otherwise go to step 14 Clean areas around choke lever shaft assembly and self relieving choke mechanism thoroughly Note position of spring hooks and choke plate for correct reassembly later Remove screws attaching choke plate to choke shaft Pull shaft out of carburetor body note preload of spring and discard removed parts Clean I D of both choke shaft bores as required Install new spring plastic dust seal cover and dust seal on shaft Slide choke shaft assembly into carburetor connecting spring hooks to levers Before seating choke shaft completely lever needs to be rotated clockwise slightly to get past stop This preloads choke plate for proper starting function Position and reinstall choke plate to flat side of choke shaft Start screws Close choke and check plate alignment within carburetor throat then tighten screws securely Do not overtighten Check for proper operation and free movement of parts KohlerEngines com 25 Fuel System 14 Clean carburetor body main jets vent ports seats etc using a good commercially available carburetor solvent Keep solvent away from plastic or rubber parts if non compatible or damage may occur Use clean dry compressed air to blow out internal channels and po
28. strong detergent capable of breaking down machining oil while maintaining a good 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 N EEE HH i Model Dimension A CV682 13 mm 0 5118 in CV732 CV742 6 mm 0 2362 in CV752 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 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 above bottom of piston skirt at dimension A 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 KohlerEngines com 53 Reassembly B
29. sure seal bore of crankcase is clean and free of any nicks or burrs 2 Apply a light coat of engine oil to outside diameter of oil seal 3 Drive oil seal into crankcase using a seal driver Make sure oil seal is installed straight and true in bore and tool bottoms against crankcase Install Governor Cross Shaft 1 Lubricate governor cross shaft bearing surfaces in crankcase with engine oil 2 Slide small lower washer onto governor cross shaft and install cross shaft from inside of crankcase 3 Install nylon washer onto governor cross shaft then start push on retaining ring Hold cross shaft up in position place a 0 50 mm 0 020 in feeler gauge on top of nylon washer and push retaining ring down shaft to secure Remove feeler gauge which will have established proper end play Install Crankshaft Carefully slide flywheel end of crankshaft through main bearing in crankcase 24 690 37 Rev B Install Connecting Rods with Pistons and Rings Reassembly Install Camshaft Piston and Connecting Rod Details A Cylinder 1 B Cylinder 2 NOTE Cylinders are numbered on crankcase Make sure to install piston connecting rod and end cap into its appropriate cylinder bore as previously marked at disassembly Do not mix end caps and connecting rods NOTE Proper orientation of piston connecting rod assemblies inside engine is extremely important Improper orientation can cause extensi
30. surface is on crankcase so tool teeth engage flywheel ring Kea gear teeth Bosses will lock tool and flywheel in 3 Finda 1 in long capscrew with correct thread size to position for loosening tightening or removing with a match threads in connecting rod puller 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 24 690 37 Rev B 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 Engine Will Not Crank e Battery connected backwards e Blown fuse e Carburetor solenoid malfunction e Choke not closing e Clogged fuel line or fuel filter e Diode in wiring harness failed in open circuit mode e DSAI or DSAM malfunction e Empty fuel tank e Faulty electronic control unit e Faulty ignition coil s e Faulty spark plug s e Fuel pump malfunction vacuum hose clogged or leaking e Fuel shut off valve closed e Ignition module s faulty or improperly gapped e Insufficient voltage to electronic control unit e Interlock switch is engaged or faulty e Key switch or kill sw
31. 070 0 590 mm 0 0028 0 0230 in Bore in crankcase New Max Wear Limit 40 965 41 003 mm 1 6128 1 6143 in 41 016 mm 1 6148 in Crankshaft to Sleeve Bearing crankcase Running Clearance New 0 03 0 09 mm 0 0012 0 0035 in Bore in oil pan New 40 987 40 974 mm 1 6136 1 6131 in Crankshaft Bore in oil pan to Crankshaft Running Clearance New 0 039 0 074 mm 0 0015 0 0029 in Flywheel End Main Bearing Journal O D New O D Max Wear Limit Max Taper Max Out of Round 40 913 40 935 mm 1 6107 1 6116 in 40 84 mm 1 608 in 0 022 mm 0 0009 in 0 025 mm 0 0010 in 3Values are in Metric units Values in parentheses are English equivalents 5 Lubricate threads with engine oil prior to assembly 8 KohlerEngines com 24 690 37 Rev B CLEARANCE SPECIFICATIONS Specifications CV682 CV732 CV742 CV752 Crankshaft continued Oil Pan End Main Bearing Journal O D New O D Max Wear Limit Max Taper Max Out of Round Connecting Rod Journal O D New O D Max Wear Limit Max Taper Max Out of Round T LR PTO End Crank in Engine Entire Crank in V Blocks 40 913 40 935 mm 1 6107 1 6116 in 40 84 mm 1 608 in 0 022 mm 0 0009 in 0 025 mm 0 0010 in 35 955 35 973 mm 1 4156 1 4163 in 35 94 mm 1 415 in 0 018 mm 0 0007 in 0 025 mm 0 0010 in 0 279 mm 0 0110 in 0 10 mm 0 0039 in Cylinder Bore
32. E Paper element cannot be blown out with compressed air 20 KohlerEngines com 1 Unhook retaining clips and remove end cap s 2 Check and clean inlet screen if equipped 3 Pull air cleaner element out of housing and replace Check condition of inner element replace when dirty 4 Check all parts for wear cracks or damage and that ejector area is clean 5 Install new element s 6 Reinstall end cap s with dust ejector valve screen down secure with retaining clips BREATHER TUBE Ensure both ends of breather tube are properly connected AIR COOLING A WARNING Hot Parts can cause severe burns th Gi 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 spraying water at wiring harness or any electrical components Refer to Maintenance Schedule 24 690 37 Rev B Typical carbureted fuel system and related components include e Fuel tank and valve e Fuel lines e In line fuel filter e Fuel pump e 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 M
33. Install Spark Plugs 1 Check gap using wire feeler gauge Adjust gap to 0 76 mm 0 030 in 2 Install plug into cylinder head 3 Torque plug to 27 N m 20 ft Ib Install Ignition Modules 1 Rotate flywheel to position magnet away from ignition module bosses 2 CDI modules are installed with spark plug lead wire from module always away from cylinder On cylinder 1 single kill tab should be towards you On cylinder 2 single kill tab should be away from you in MDI modules are installed with flat side out towards you 3 Install each ignition module to crankcase bosses Slide modules up as far away from flywheel as possible and snug screws to hold them in position 4 Rotate flywheel to position magnet directly under one ignition module 24 690 37 Rev B Reassembly 5 Insert a 0 25 mm 0 009 in flat feeler gauge between magnet and ignition module Loosen screws enough to allow magnet to pull module down against feeler gauge Torque screws to 4 0 6 2 N m 35 55 in Ib Repeat steps 4 through 6 for other ignition module 8 Rotate flywheel back and forth checking for clearance between magnet and ignition modules Make sure magnet does not strike modules Check gap with a feeler gauge and readjust if necessary Final air gap 0 203 0 305 mm 0 008 0 012 in Install Intake Manifold Torque Sequence 1 Install intake manifold and new gaskets adhesive side to manifold with wirin
34. KOHLER Command PRO CV682 CV732 CV742 CV752 Service Manual IMPORTANT Read all safety precautions and instructions carefully before operating equipment Refer to operating instruction of equipment that this engine powers Ensure engine is stopped and level before performing any maintenance or service Safety Maintenance 5 Specifications 13 Tools and Aids 16 Troubleshooting 20 Air Cleaner Intake 21 Fuel System 27 Governor System 28 Lubrication System 30 Electrical System 37 Starter System 41 _ Disassembly Inspection and Service 54 Reassembly GN 24 690 37 Rev B KohlerEngines com Safety SAFETY PRECAUTIONS A WARNING A hazard that could result in death serious injury or substantial property damage A 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 A WARNING Explosive Fuel can cause fires and severe burns LA GL 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 A WARNING Accidental Starts can 7 rt cause severe injury or
35. T 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 4 Install adapter into spark plug hole but do not attach it to tester at this time 5 Turn regulator knob completely counterclockwise 6 Connect an air source of at least 50 psi to tester 7 Turn
36. Use a hydraulic lifter tool Do not use a magnet to remove lifters Mark lifters by location as either intake or exhaust and cylinder 1 or 2 Hydraulic lifters should always be reinstalled in same position KohlerEngines com 24 690 37 Rev B Disassembly Inspection and Service Disassemble Cylinder Heads NOTE These engines use valve stem seals on intake valves Use a new seal whenever valve is removed or if seal is deteriorated or damaged in any way Never reuse an old seal 1 Remove screws rocker arm pivots and rocker arms from cylinder head 2 Compress valve springs using a valve spring compressor 3 Once valve spring is compressed remove following items e Valve spring keepers e Valve spring retainers e Valve springs e Valve spring caps e Intake and exhaust valves mark position e Valve stem seal intake valve only 4 Repeat above procedure for other cylinder head Do not interchange parts from 1 cylinder head to other Inspection and Service Valve Details OF EXHAUST A INSERT i INTAKE INSERT EXHAUST VALVE INTAKE VALVE Dimension Intake Exhaust A Seat Angle 89 89 B Insert O D 36 987 37 013 mm 1 4562 1 4572 in 32 987 33 013 mm 1 2987 1 2997 in C Guide Depth 4 mm 0 1575 in 6 5 mm 0 2559 in D Guide I D 7 038 7 058 mm 0 2771 0 2779 in 7 038 7 058 mm 0 2771 0 2779 in E Valve Head Diameter 33 37 33 63 mm
37. 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 Charge rate does not increase when load is applied Test stator and rectifier regulator steps 2 and 3 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 more Stator is OK Rectifier regulator is faulty replace Voltage is less than 28 volts Stator is faulty replace Test stator further using an ohmmeter steps 3 and 4 3 With engine stopped measure resistance across stator leads using an ohmmeter Condition Conclusion Resistance is 0 1 0 2 ohms Stator is OK Resistance is 0 ohms Stator is shorted replace Resistance is infinity ohms Stator is open replace 4 With engine stopped measure resistance from each stator lead to ground using an ohmmeter Condition Conclusion Resistance is infinity ohms no continuity Stator is OK not shorted to ground Resistance or continuity measured Stator leads are shorted to ground replace 36 To test charging system for battery continuously charging at high rate 1 With engine running at 3600 RPM measu
38. adually decrease pressure through range of 2 5 psi Tester should indicate a change to no continuity switch open down to 0 psi 4 Replace switch if it does not operate as specified 24 690 37 Rev B KohlerEngines com Lubrication System 29 Electrical System SPARK PLUGS Inspection A CAUTION W Electrical Shock can cause injury Do not touch wires while engine is running Spark Plug Component and Details Bo A Wire Gauge B Spark Plug C 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 Thread Size 14 mm Gap 0 76 mm 0 03 in Reach 19 1 mm 3 4 in Hex Size 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 30 KohlerEngines com 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 plug
39. aft Lubricant Valspar ZZ613 Kohler 25 357 14 S Dielectric Grease GE Novaguard G661 Kohler 25 357 11 S Dielectric Grease Loctite 51360 Kohler Electric Starter Drive Lubricant Inertia Drive Kohler 52 357 01 S Kohler Electric Starter Drive Lubricant Solenoid Shift Kohler 52 357 02 S RTV Silicone Sealant Loctite 5900 Heavy Body in 4 oz aerosol dispenser Only oxime based oil resistant RTV sealants such as those listed are approved for use Loctite Nos 5900 or 5910 are recommended for best sealing characteristics Kohler 25 597 07 S Loctite 5910 Loctite Ultra Black 598 Loctite Ultra Blue 587 Loctite Ultra Copper 5920 Spline Drive Lubricant Kohler 25 357 12 S 14 KohlerEngines com 24 690 37 Rev B Tools and Aids FLYWHEEL HOLDING TOOL ROCKER ARM CRANKSHAFT TOOL A flywheel holding tool can be made out of an old junk A spanner wrench to lift rocker arms or turn crankshaft flywheel ring gear and used in place of a strap wrench may be made out of an old junk connecting rod 1 Using an abrasive cut off wheel cut out a six tooth 1 Find a used connecting rod from a 10 HP or larger segment of ring gear as shown engine Remove and discard rod cap 2 Grind off any burrs or sharp edges 2 Remove studs of a Posi Lock rod or grind off 3 Invert segment and place it between ignition bosses Toning steps of a Command rod so joint
40. aintenance FUEL LINE Low permeation fuel line must be installed on carbureted Kohler Co engines to maintain EPA and CARB regulatory compliance FUEL PUMP These engines use a pulse style fuel pump Pumping action of pulse style pumps is created by oscillation of positive and negative pressures within crankcase This pressure is transmitted to pulse pump through rubber hose connected between pump and crankcase Pumping action causes diaphragm on inside of pump to pull fuel in on its downward stroke and to push it into carburetor on its upward stroke Two check valves prevent fuel from going backward through pump FUEL SYSTEM TESTS Fuel System Performance Minimum fuel delivery rate must be 7 5 L hr 2 gal hr with a pressure at 0 3 psi and a fuel lift of 24 in A 1 3 L hr 0 34 gal hr fuel rate must be maintained at 5 Hz Fuel Pump Replacement NOTE Make sure orientation of new pump is consistent with removed pump Internal damage may occur if installed incorrectly To replace pulse pump follow these steps Note orientation of pump before removing 1 Disconnect fuel lines from inlet outlet and pulse fittings on fuel pump 2 Remove screws and take off pump 3 Connect pulse line to new fuel pump and make sure opposite end is properly connected to fitting on crankcase 4 Attach new fuel pump using screws Torque screws to 2 3 N m 20 in Ib 5 Reconnect fuel lines to inlet and outlet fittings a
41. all traces of cleaner are removed before engine is reassembled and placed into operation 24 690 37 Rev B Even small amounts of these cleaners can quickly break down lubricating properties of engine oil Disconnect Spark Plug Leads NOTE Pull on boot only to prevent damage to spark plug lead 1 Disconnect leads from spark plugs 2 Shut off fuel supply KohlerEngines com 41 Disassembly Inspection and Service Drain Oil From Crankcase and Remove Oil Filter 1 Remove oil fill cap dipstick and 1 oil drain plug 2 Allow ample time for oil to drain from crankcase and oil filter 3 Remove mounting screw and detach oil fill tube 4 Remove and discard oil filter Remove Oil Cooler if equipped 1 Disconnect fuel lines at carburetor and at in line fuel filter 2 Disconnect pulse vacuum line from crankcase 3 Remove mounting screws from blower housing and remove fuel pump and lines as an assembly Remove Throttle and Choke Controls Control Panel Components 1 Use a 5 16 Allen wrench to remove oil filter nipple 2 Separate filter adapter from oil pan leaving oil lines attached Remove screws mounting oil cooler to blower housing Remove cooler lines and filter adapter as an assembly Remove Muffler Remove exhaust system and attaching hardware from engine On engines equipped with a port liner remove it now Remove Air Cleaner Assembly 1 Disconnect breather hose from air
42. amaged seals or gaskets or loose fasteners Check air cleaner cover and base for damage or indications of improper fit and seal 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 Check carburetor throat for dirt Dirt in throat is further indication that air cleaner was not functioning properly Check if oil level is within operating range on dipstick If it is above sniff for gasoline odor 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 A WARNING Cleaning Solvents can cause severe injury or 4 death Use only in well ventilated areas away from ignition sources Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and 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 clea
43. amp to body of rectifier regulator being tested 2 Connect tester red lead to B terminal of rectifier regulator and 2 black tester leads to 2 AC terminals 3 Plug tester into proper AC outlet power for tester being used Turn on power switch POWER light should be illuminated and 1 of 4 status lights may be on as well This does not represent condition of part 4 Press TEST button until a click is heard and then release Momentarily 1 of 4 status lights will illuminate indicating condition of part 34 KohlerEngines com 24 690 37 Rev B Electrical System To test 20 25 amp rectifier regulators 1 20 amp Connect single lead adapter in between B center terminal of rectifier regulator being tested and squared single end of tandem adapter lead 25 amp Connect squared single end of tandem lead adapter to B center red lead of rectifier regulator being tested 2 Connect tester ground lead with spring clamp to body of rectifier regulator 3 Connect red lead and 1 of black leads to pair of terminals on open end of tandem adapter lead connections are not location specific 4 Connect remaining black lead from tester to 1 of outer AC terminals on rectifier regulator 5 Plug tester into proper AC outlet power for tester being used Turn on power switch POWER light should be illuminated and 1 of 4 status lights may be on as well This does not represent condition of part 6 Press TEST button until a click is heard and t
44. an old push rod and chuck it in a drill press 2 Lay a rag or shop towel on table of drill press and place lifter open end up on towel 3 Lower chucked push rod until it contacts plunger in lifter Slowly pump plunger 2 or 3 times to force oil out of feed hole in side of lifter 24 690 37 Rev B Fiywheelllgnition Components Washer 24 690 37 Rev B A Flywheel Screw B C Flywheel D Stator E Ignition Module F Stud G Screw H Woodruff Key I Intake Manifold J Backing Plate K Magnet Disassembly Inspection and Service Remove Intake Manifold 1 Remove screws securing intake manifold to cylinder heads Note which screws hold wiring clamps 2 Remove intake manifold and intake manifold gaskets 3 Leave wiring harness attached to manifold 4 Remove violet B lead from stator clip attached to rectifier regulator Remove Flywheel NOTE Always use a flywheel strap wrench or holding tool to hold flywheel when loosening or tightening flywheel screw Do not use any type of bar or wedge to hold flywheel Use of such tools could cause flywheel to become cracked or damaged NOTE Always use a flywheel puller to remove flywheel from crankshaft Do not strike crankshaft or flywheel as these parts could become cracked or damaged Striking puller or crankshaft can cause crank gear to move affecting crankshaft endplay 1 Use a flywheel strap wrench or holding tool
45. arks 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 volume 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 fuel system 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 24 690 37 Rev B Engine Dimensions Specifications n
46. ating Pin Locking Tab Thrust Washer z me IT 1 OU Governor Gear O S A o0 m a gt Governor Gear Shaft 24 690 37 Rev B Governor System Governor works as follows Centrifugal force acting on rotating governor gear assembly causes flyweights to move outward as speed increases Governor spring tension moves them inward as speed decreases As flyweights move outward they cause regulating pin to move outward Regulating pin contacts tab on cross shaft causing shaft to rotate One end of cross shaft protrudes through crankcase Rotating action of cross shaft is transmitted to throttle lever of carburetor through external linkage When engine is at rest and throttle is in FAST 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 When load is applied and engine speed and governor gear speed decreases governor spring tension moves governor lever 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 Governor Adjustments NOTE Do not tam
47. ave spark Be certain drive 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 Identify white kill lead of engine wiring harness connector Establish a connection to a known good ground location Engine should kill completely If not or only one cylinder is affected check ignition modules and white kill lead connection for affected module 24 690 37 Rev B KohlerEngines com 33 Electrical System Test for Spark NOTE If 2 testers are available testing can be performed simultaneously for both cylinders However if only 1 tester is available 2 individual tests must be performed Side not being tested must have spark plug lead con
48. barrel retaining nuts Kohler 52 455 04 S Oil Pressure Test Kit For testing verifying oil pressure on pressure lubricated engines Kohler 25 761 06 S Rectifier Regulator Tester 120 volt current Rectifier Regulator Tester 240 volt current For testing rectifier regulators Components of 25 761 20 S and 25 761 41 S CS PRO Regulator Test Harness Special Regulator Test Harness with Diode Spark Advance Module SAM Tester For testing SAM ASAM and DSAM on engines with SMART SPARK Starter Servicing Kit All Starters For removing and reinstalling drive retaining rings and brushes Individual component available Starter Brush Holding Tool Solenoid Shift Kohler 25 761 20 S Kohler 25 761 41 S Design Technology Inc DTI 031 DTI 033 Kohler 25 761 40 S SE Tools KLR 82411 SE Tools KLR 82416 Triad OHC Timing Tool Set For holding cam gears and crankshaft in timed position while installing timing belt Kohler 28 761 01 S Valve Guide Reamer K and M Series For properly sizing valve guides after installation Design Technology Inc DTI K828 Valve Guide Reamer O S Command Series 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 For hand reaming using Kohler 25 455 12 S reamer AIDS Description Kohler 25 455 12 S Design Technology Inc D 8 Source Part No Camsh
49. camshaft and crankshaft into their mating bearings Rotate crankshaft slightly to help engage oil pump and governor gear meshes 5 Install screws securing oil pan to crankcase Torque fasteners to 24 4 Nm 216 in Ib following sequence On some engines one mounting screw is plated Plated screw is typically installed in hole location 6 A Flywheel Screw B Washer C Flywheel D Stator E Ignition Module F Stud G Screw H Woodruff Key I Intake Manifold J Backing Plate K Magnet Install Stator and Backing Plate 1 Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to stator mounting holes 2 Position stator aligning mounting holes so that leads are at bottom towards crankcase 3 Install and torque screws to 6 2 N m 55 in Ib 56 KohlerEngines com 24 690 37 Rev B 4 Route stator leads in crankcase channel then install backing plate Secure with screws Torque screws to 7 3 N m 65 in Ib Install Flywheel A CAUTION Damaging Crankshaft and Flywheel can cause personal injury Me 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 Cylinder Head Components Reassembly NOTE Before installing flywheel make sure crankshaft taper and flywheel hub are clean dry and completely free of any
50. cessively worn cracked or broken Brush Replacement 4 brushes and springs are serviced as a set Use a new Kohler brush and spring kit if replacement is necessary 1 Perform steps 1 5 in Starter Disassembly 2 Remove screws securing brush holder assembly to end cap plate Note orientation for reassembly later Discard old brush holder assembly 3 Clean component parts as required 4 New brushes and springs come preassembled in a brush holder with a protective sleeve that will also serve as an installation tool 5 Perform Steps 10 13 in Starter Reassembly sequence Installation must be done after armature drive lever and frame are installed if starter has been disassembled 24 690 37 Rev B Starter System Starter Reassembly NOTE Always use a new retainer Do not reuse old retainers that have been removed NOTE Correctly installed center pivot section of drive lever will be flush or below machined surface of housing 1 Apply drive lubricant to armature shaft splines Install drive pinion onto armature shaft 2 Install and assemble stop collar retainer assembly a Install stop collar down onto armature shaft with counter bore recess up b Install a new retainer in larger rear groove of armature shaft Squeeze with a pliers to compress it in groove c Slide stop collar up and lock it into place so recess surrounds retainer in groove If necessary rotate pinion outward on armature splines a
51. ch cover and finger tighten 5 Torque valve cover fasteners to 6 2 N m 55 in Ib using sequence shown 6 Install rubber grommet into cylinder 1 valve cover Install oil separator into grommet and secure to blower housing with mounting screws 24 690 37 Rev B Control Panel Components Reassembly QQ 3 M Sy Throttle Control Install Carburetor Tab Up y burns LL Do not fill fuel tank while engine is hot or A WARNING running Explosive Fuel can cause fires and severe 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 24 690 37 Rev B A Control Bracket Lock Nut Lever D Flat Washer E Throttle Shaft Spring Throttle Shaft en Hu oe one I Se Spacer Governor Spring L Governed Idle Spring Governor Lever Linkage Spring Throttle Linkage P Air Cleaner Gasket Q Carburetor Carburetor Gasket Choke Lever T Choke Linkage Use a new carburetor gasket Make sure tab on gasket is up Install carburetor throttle linkage and choke linkage as an assembly Throttle linkage and choke linkage should both be assembled from carburetor outward Connect ground lead and fuel solenoi
52. cleaner Remove nuts securing air cleaner and any attached clips to mounting studs 2 Remove screws securing support bracket to air cleaner assembly 3 Remove air cleaner assembly and gasket off mounting studs Remove Control Panel 1 Disconnect choke control cable and throttle control ow o ig T B fo RE N a cable from control bracket A Control Bracket B Lock Nut 2 Remove lock nut securing throttle control lever flat c Throttle Control D Flat Washer washer throttle shaft spring and throttle control Lever shaft to control bracket E Throttle Shaft Spring F Throttle Shaft 3 Remove panel from blower housing G Throttle Shaft H Throttle Control 4 Throttle control shaft and throttle shaft bracket do Bracket Lever not need to be removed from cylinder head at this time To do so disconnect governor spring from I N J Spacer throttle control lever and governed idle spring from governed idle bracket Remove screws securing K Governor Spring L Governed Idle Spring throttle shaft bracket to cylinder head M Governor Lever N Linkage Spring Remove Fuel Pump o Throttle Linkage P Air Cleaner Gasket Q Carburetor R Carburetor Gasket A WARNING S Choke Lever T Choke Linkage Explosive Fuel can cause fires and severe burns LA 4 4 Do not fill fuel tank while engine is hot or running Gasoline is extremely flammable and its vapors can explode if ignited Store
53. d lead KohlerEngines com 63 Reassembly Install External Governor Controls 1 Install governor lever onto governor cross shaft 2 Connect choke linkage into bushing lever from back Make certain that control shaft offset is back Connect throttle linkage and spring to governor lever 3 Move governor lever toward carburetor as far as it will go wide open throttle and hold in position 4 Insert a long thin rod or tool into hole on cross shaft and rotate shaft counterclockwise viewed from end as far as it will turn then torque nut to 6 8 N m 60 in Ib 5 Connect governor spring from throttle control lever to appropriate hole in governor lever Connect governed idle spring from governed idle bracket to G hole in governor lever Refer to Governor Lever and Hole Position RPM Chart Note that hole positions are counted from pivot point of governor lever Governor Lever Hole Position Governor Lever and Hole Position RPM Chart Governed Idle 10 Regulation A Governor Lever B Governed Idle Hole C Hole 1 D Hole 2 E Hole 3 F Hole 4 High Idle Governor Lever Governor PM Hole No sprna or 4200 4 Black 4000 3 Purple 3950 3 Purple 3900 3 Green 3850 3 Green 3800 3 Red 3750 3 Red 3700 2 Green 3650 2 Green 3600 2 Red 3550 2 Red 3500 2 Clear 3450 2 Clear 3400 2 Clear 3350 2 Clear 3300 2 Clear Install Electric Starter Moto
54. death Disconnect and ground spark plug lead s before servicing A CAUTION X Electrical Shock can cause injury 7 Do not touch wires while engine is running Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery A WARNING Ro Rotating Parts can cause N severe injury Stay away while engine is in operation A WARNING A CAUTION Damaging Crankshaft and Flywheel can cause Ro personal injury LF Hot Parts can cause severe burns Gils Gi eS Do not touch engine while operating or just after stopping 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 Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed Never operate engine with heat shields or guards removed A WARNING Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled A WARNING Cleaning Solvents can H cause severe injury or 4 death Use only in well vent
55. dle or slow position Turn low idle speed adjusting screw in or out to obtain allow idle speed of 1500 RPM 75 RPM ne Idie Speed Adjustment If equipped 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 1500 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 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 intended high speed no load RPM Governed idle speed must be set before making this adjustment High Speed RPM Adjustment 1 With engine running move throttle control to fast 2 Turn adjustment screw inward to decrease or outward to increase RPM speed 3 Stop when desired RPM speed is obtained 24 690 37 Rev B Carburetor Servicing A WARNING Accidental Starts can cause severe injury or death Disconnect
56. e s improperly set Idle speed adjusting screw improperly set Incorrect governed idle setting Inadequate fuel supply Low compression e Quality of fuel dirt water stale mixture e Restricted fuel tank cap vent Engine Overheats 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 e 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 e Cooling fan broken e Excessive engine load e Fan belt failed off e Faulty carburetor e High crankcase oil level e Lean fuel mixture e Low cooling system fluid level e Low crankcase oil level e Radiator and or cooling system components clogged restricted or leaking e Water pump belt failed broken e Water pump malfunction Engine Knocks e Excessive engine load e Hydraulic lifter malfunction e Incorrect oil viscosity type e Internal wear or damage e Low crankcase oil level e Quality of fuel dirt water stale mixture 24 690 37 Rev B Engine Loses Power e Dirty air cleaner element e Engine overheated e Excessive engine load e Restricted exhaust e Faulty spark
57. eignition damage is often more severe than detonation damage Preignition is caused by a hot spot in combustion chamber from sources such as glowing carbon deposits blocked cooling fins an improperly seated valve or wrong spark plug s Replacement pistons are available in STD bore size and 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize Replacement pistons include new piston ring sets and new piston pins Replacement ring sets are also available separately for STD 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize pistons Always use new piston rings when installing pistons Never use old rings Some important points to remember when servicing piston rings 1 Cylinder bore must be de glazed before service ring sets are used 2 If cylinder bore does not need re boring and if old piston is within wear limits and 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 new rings on piston place top 2 rings each in turn in its running area in cylinder bore and check end gap 80 mm bore engines Top compression ring end gap clearance is 0 100 0 279 mm 0 0039 0 0110 in for a new bore or 0 490 mm 0 0192 in for a used bore Middle compression ring end cap is 1 400 1 679 mm 0 0551 0 0661 in for a new bore or 1 941 mm 0 0764 in for a used bore 83 mm bore engines Top compression ring end gap clearance is 0 189 0 277
58. erEngines com 67 1P24 690 37 2015 by Kohler Co All rights reserved 8 85612 28087 9 68 KohlerEngines com 24 690 37 Rev B
59. ertighten Solenoid Tests NOTE DO NOT leave 12 volt test leads connected to solenoid for any time over what is necessary for performing each of individual tests Internal damage to solenoid may occur Disconnect all leads from solenoid including positive brush lead attached to lower stud terminal Remove mounting hardware and separate solenoid from starter for testing To test solenoid pull in coil plunger Actuation 1 Use a 12 volt power supply and 2 test leads 2 Connect 1 lead to flat spade S start terminal on solenoid Momentarily connect other lead to lower large post terminal When connection is made solenoid should energize audible click and plunger retract Repeat test several times Continuity 1 Use an ohmmeter set to audible or Rx2K scale and connect 2 ohmmeter leads to 2 large post terminals 2 Perform solenoid pull in coil plunger actuation test and check for continuity Onmmeter should indicate continuity Repeat test several times To test solenoid hold in coil Function 1 Connect a 12 volt test lead to flat spade S start terminal on solenoid and other lead to body or mounting surface of solenoid 2 Manually push plunger IN and check if coil holds plunger retracted Do not allow test leads to remain connected to solenoid for a prolonged period of time Continuity 1 Use an ohmmeter set to audible or Rx2K scale and connect 2 ohmmeter leads to 2 large post terminals 2 Perform preceding solenoid hold in c
60. f 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 float 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 2 main jets and further metered through slow jets Air and fuel are mixed in body of slow jet and exit to transfer port From transfer port air fuel mixture is delivered to idle progression chamber From idle progression chamber a
61. ffle using remaining screws and finger tighten Do not torque screws at this time they will be tightened after blower housing and outer baffles are installed Install Blower Housing and Outer Baffles Wires on Starter Side of Engine Les AL NOTE Do not completely tighten screws until all items are installed to allow shifting for hole alignment 1 Pull wire harness and spark plug leads out through appropriate openings in shrouding 2 Slide blower housing into position over front edge of inner baffle Start a few of screws to hold it in place 24 690 37 Rev B Reassembly 3 Position outer baffles and secure using screws two long two short in front mounting holes into cylinder head including any lifting strap or attached bracket s Install two short screws in upper mounting holes of outer baffles into backing plates Use short screw on left side to mount wire harness bracket Be sure any leads are routed out through proper offsets or notches so they will not be pinched between blower housing and baffles 4 Tighten all shrouding fasteners Torque blower housing screws to 6 2 N m 55 in Ib in a new hole or to 4 0 N m 35 in Ib in a used hole To
62. from inadequate or contaminated lubrication If cylinder bore is badly scored excessively worn tapered or out of round resizing is necessary Use an inside micrometer to determine amount of wear refer to Specifications then select nearest suitable oversize of either 0 25 mm 0 010 in or 0 50 mm 0 020 in Resizing to 1 of these oversizes will allow usage of available oversize piston and ring assemblies First resize using a boring bar then use following procedures for honing cylinder 24 690 37 Rev B Honing Detail f A 23 33 Crosshatch NOTE Kohler pistons are custom machined to exacting tolerances When oversizing a cylinder it should be machined exactly 0 25 mm 0 010 in or 0 50 mm 0 020 in over new diameter refer to Specifications A corresponding oversize Kohler replacement piston will then fit correctly 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 crossbore 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 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
63. g harness attached to cylinder heads Slide any wiring harness clips onto appropriate bolts before installing Make sure gaskets are in proper orientation Torque screws in two stages first to 7 4 N m 66 in Ib then to 9 9 N m 88 in Ib using sequence shown 2 Connect each kill lead to tab terminal on each ignition module 3 If air cleaner support bracket was removed from intake manifold reinstall it Secure to top of intake manifold with 2 screws Torque screws to 9 9 N m 88 in Ib KohlerEngines com 59 Reassembly External Engine Components A Guard B Blower Housing C Fuel Filter D Rectifier Regulator E Outer Baffle F Electric Starter G Inner Baffle H Air Cleaner I Air Cleaner Gasket J Support Bracket K Fuel Pump L Oil Cooler M O ring N Nipple o Oil Filter P Plastic Debris Screen Q Metal Debris Screen R Support Ring S Spacer T Fan 60 KohlerEngines com 24 690 37 Rev B Install Breather Cover and Inner Baffle Breather Cover Torque Sequence 2 1 Be sure sealing surfaces of crankcase and breather cover are clean of old gasket material Do not scrape surfaces as this could result in leakage 2 Check to make sure there are no nicks or burrs on sealing surfaces 3 Position breather gasket and cover on crankcase Install first screws in locations 3 and 4 as shown Finger tighten at this time 4 Install inner ba
64. gainst retainer to help seat collar around retainer 3 Install offset thrust stop washer so smaller offset of washer faces retainer collar 4 Apply a small amount of oil to bearing in drive end cap and install armature with drive pinion 5 Lubricate fork end and center pivot of drive lever with drive lubricant Position fork end into space between captured washer and rear of pinion 6 Slide armature into drive end cap and at same time seat drive lever into housing 7 Install backup washer followed by rubber grommet into matching recess of drive end cap Molded recesses in grommet should be out matching and aligned with those in end cap 8 Install frame with small notch forward onto armature and drive end cap Align notch with corresponding section in rubber grommet Install drain tube in rear cutout if it was removed previously 9 Install flat thrust washer onto commutator end of armature shaft 10 Starter reassembly when replacing brushes brush holder assembly a Hold starter assembly vertically on end housing and carefully position assembled brush holder assembly with supplied protective tube against end of commutator armature Mounting screw holes in metal clips must be up out Slide brush holder assembly down into place around commutator and install positive brush lead grommet in cutout of frame Protective tube may be saved and used for future servicing Starter reassembly when not replacing b
65. gasket Secure with new screws Torque screws to 2 3 2 7 N m 20 24 in Ib 23 Reattach accelerator pump vacuum hose 24 Use new mounting gaskets for air cleaner and carburetor Reinstall carburetor and disassembled components following Reassembly procedures 25 Reconnect spark plug leads and negative battery cable Start engine and perform Low Idle Speed Adjustment 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 26 KohlerEngines com 24 690 37 Rev B GOVERNOR Engine is equipped with a centrifugal flyweight mechanical governor It is designed to hold engine speed constant under changing load conditions Governor gear flyweight mechanism is mounted inside crankcase on oil pan and is driven off gear on camshaft Governor Components Inside Engine Choke Lever Throttle Shaft Control Bracket Choke Linkage Governed Idle Bracket Throttle Control Lever Governor Spring Governed Idle Spring Governor Lever Linkage Spring Throttle Linkage Regul
66. hen release Momentarily 1 of 4 status lights will illuminate indicating partial condition of part Condition Conclusion 4 amp 15 Amp 20 amp 25 amp OK green or HIGH light comes on Part is good and may be used Disconnect tester black lead attached and stays steady to 1 AC terminal and reconnect it to other AC terminal Repeat test If OK green light comes on again part is good and may be used NOTE A flashing LOW light can Rectifier regulator is faulty and should not be used Other lights come on also occur as a result of an inadeguate ground lead connection Make certain connection location is clean and clamp is secure 24 690 37 Rev B KohlerEngines com 35 Electrical System 15 20 25 Amp Battery Charging Systems NOTE Always zero ohmmeter on each scale before testing to ensure accurate readings Voltage tests should be made with engine running at 3600 RPM with no load Battery must be good and fully charged When problems occur in keeping battery charged or battery charges at high rate charging system or battery might be causing problems 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
67. ilated areas away from ignition sources A cauTION Failure to utilize or reassemble debris screen as designed could ry result in debris screen N failure and serious personal injury Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent KohlerEngines com 24 690 37 Rev B MAINTENANCE INSTRUCTIONS Maintenance A WARNING Accidental Starts can cause severe injury or death Disconnect and ground spark plug lead s before servicing AS k Before working on engine or eguipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery 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 Weekly e Check air cleaner element Air Cleaner Intake Every 100 Hours or Annually e Change oil Lubrication System e Remove cooling shrouds and clean cooling areas Air Cleaner Intake e Check oil cooler fins clean as necessary if equipped Lubrication System Every 200 Hours e Change oil filter Lubrication System e Replace fuel filter
68. inion and inspect following areas e Pinion teeth for abnormal wear or damage e Surface between pinion and clutch mechanism for nicks or irregularities which could cause seal damage e Check drive clutch by holding clutch housing and rotating pinion Pinion should rotate in only 1 direction Brushes and Springs Detail A Wear Limit Length Inspect both springs and brushes for wear fatigue or damage Measure length of each brush Minimum length for each brush is 7 6 mm 0 300 in Replace brushes if they are worn undersize or condition is questionable 24 690 37 Rev B Armature Components and Details A A Commutator O D B Mica Insulation C Insulation Check D Armature Coil E Continuity Check 1 Clean and inspect commutator outer surface Mica insulation must be lower than commutator bars undercut to ensure proper operation of commutator 2 Use an ohmmeter set to Rx1 scale Touch probes between 2 different segments of commutator and check for continuity Test all segments Continuity must exist between all or armature is bad 3 Check for continuity between armature coil segments and commutator segments There should be no continuity If continuity exists between any 2 armature is bad 4 Check armature windings insulation for shorting Shift Fork Check that shift fork is complete and pivot and contact areas are not ex
69. ir fuel mixture is metered through idle port passages At low idle when vacuum signal is weak 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 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 4 air jets fuel is drawn through main jets 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 24 KohlerEngines com NOTE Carburetor adjustments should be made only after engine has warmed up Carburetor is designed to deliver correct fuel to air 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 equipment manufacturer s recommendations Low idle governed idle speed for basic engines is 1500 RPM Place throttle control into i
70. itch in OFF position e Low oil level e 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 Battery is discharged e Faulty electric starter or solenoid e Faulty key switch or ignition switch e Interlock switch is engaged or faulty e Loose wires or connections that intermittently ground ignition kill circuit e Pawls not engaging in drive cup e Seized internal engine components Engine Runs But Misses e Carburetor adjusted incorrectly e Engine overheated e Faulty spark plug s e Ignition module s faulty or improperly gapped e Incorrect crankshaft position sensor air gap e Interlock switch is engaged or faulty e Loose wires or connections that intermittently ground ignition kill circuit e Quality of fuel dirt water stale mixture e Spark plug lead s disconnected e Spark plug lead boot loose on plug e Spark plug lead loose Engine Will Not Idle e Faulty carburetor e Faulty cylinder head gasket e Faulty or misadjusted choke or throttle controls e Fuel pump malfunction vacuum hose clogged or leaking e Intake system leak e 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 Engine overheated Faulty spark plug s Idle fuel adjusting needl
71. lifters and lifter bores in crankcase with engine oil 3 Note mark or tag identifying hydraulic lifters as either intake or exhaust and cylinder 1 or cylinder 2 Install hydraulic lifters into their appropriate locations in crankcase Do not use a magnet 4 If breather reeds and stops were removed from crankcase reinstall them at this time and secure with screw Torque screw to 4 0 N m 35 in Ib Valve Stem Seals These engines use valve stem seals on intake valves and occasionally on exhaust valves Use a new seal whenever valve is removed or if seal is deteriorated or damaged in any way Never reuse an old seal Assemble Cylinder Heads Prior to installation lubricate all components with engine oil paying particular attention to lip of valve stem seal valve stems and valve guides Install in order listed below using a valve spring compressor e Intake and exhaust valves e Valve spring caps e Valve springs e Valve spring retainers e Valve spring keepers Install Cylinder Heads Torque Sequence NOTE Cylinder heads must be attached with original type of mounting hardware using either screws or mounting studs with nuts and washers Heads are machined differently for studs than for screws so fastening method cannot be altered unless heads are being replaced Do not intermix components NOTE Match numbers embossed on cylinder heads and crankcase 58 KohlerEngines com Heads Sec
72. lling camshaft 4 Slide camshaft into bearing surface of crankcase positioning timing mark of camshaft gear at 6 o clock position Make sure camshaft gear and crankshaft gear mesh with both timing marks aligned Oil Pump Assembly Oil pump is mounted inside oil pan If service was required and oil pump was removed refer to Disassembly Inspection and Service Governor Gear Assembly Governor gear assembly is located inside oil pan If service was required and governor was removed refer to Disassembly Inspection and Service Install Oil Seal in Oil Pan Oil Seal Component and Detail Y A 6 5 mm 0 255 in B Oil Seal 1 Check to make sure that there are no nicks or burrs in crankshaft bore of oil pan 2 Apply a light coat of engine oil to outside diameter of oil seal 3 Drive oil seal into oil pan using a seal driver Make sure oil seal is installed straight and true in bore to depth shown KohlerEngines com 55 Reassembly Install Oil Pan Assembly Flywheel Ignition Components Torgue Seguence 1 Be sure sealing surfaces have been cleaned and prepared Install a new O ring in oil pan 2 Check to make sure that there are no nicks or burrs on sealing surfaces of oil pan or crankcase 3 Make sure end of governor cross shaft is lying against bottom of cylinder 1 inside crankcase 4 Use anew gasket and install oil pan to crankcase Carefully seat
73. mm 0 0074 0 0109 in for a new bore or 0 531 mm 0 0209 in for a used bore Middle compression ring end cap is 1 519 1 797 mm 0 0598 0 0708 in for a new bore or 2 051 mm 0 0808 in for a used bore 5 After installing new compression top and middle rings on piston make sure top compression ring to groove side clearance and is 0 030 0 070 mm 0 0010 0 0026 in and middle compression ring to groove side clearance 0 030 0 070 mm 0 0010 0 0026 in If side clearance is greater than specified a new piston must be used 24 690 37 Rev B Install New Piston Rings Disassembly Inspection and Service Connecting Rods Piston Ring Orientation A Top Oil Ring Rail B Bottom Oil Ring Rail Gap Gap Intermediate Ring D Oil Ring Expander Gap Gap Top Ring Gap FLY Stamp 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 To install new 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 Middle compression ring center groove Install center ring using a piston ring installation tool Make sure identification mark is up or colored dye stripe if contained is to left of
74. n 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 A WARNING Carbon Monoxide can cause severe nausea fainting or death Avoid inhaling exhaust fumes A WARNING Rotating Parts can cause severe injury Stay away while engine is in operation Engine exhaust gases contain poisonous carbon monoxide Carbon monoxide is odorless colorless and can cause death if inhaled Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed 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 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 manomete
75. n Ring to Groove Side Clearance 0 030 0 070 mm 0 001 0 0026 in Oil Control Ring to Groove Side Clearance 0 060 0 190 mm 0 0022 0 0073 in Top Compression Ring End Gap New Bore 0 100 0 189 0 277 mm 0 279 mm 0 0074 0 0109 in 0 0039 0 0110 in Used Bore Max 0 490 mm 0 531 mm 0 0209 in 0 0192 in Middle Compression Ring End Gap New Bore 1 400 1 519 1 797 mm 1 679 mm 0 0598 0 0708 in 0 0551 0 0661 in Used Bore Max 1 941 mm 2 051 mm 0 0808 in 0 0764 in Thrust Face O D New 79 966 mm 82 978 mm 3 2668 in 3 1483 in Max Wear Limit 79 821 mm 82 833 mm 3 2611 in 3 1426 in Piston Thrust Face to Cylinder Bore Running Clearance 0 025 0 019 0 062 mm 0 0007 0 0024 in New 0 068 mm 0 0010 0 0027 in 3 Values are in Metric units Values in parentheses are English equivalents 7 Measure 6 mm 0 2362 in above bottom of piston skirt at right angles to piston pin 8 Measure 13 mm 0 5118 in above bottom of piston skirt at right angles to piston pin 10 KohlerEngines com 24 690 37 Rev B CLEARANCE SPECIFICATIONS Specifications CV682 CV732 CV742 CV752 Valves and Valve Lifters Hydraulic Valve Lifter to Crankcase Running Clearance 0 0241 0 0501 mm 0 0009 0 0020 in Intake Valve Stem to Valve Guide Running Clearance 0 038 0 076 mm 0 0015 0 0030 in Exhaust Valve Stem to Valve Guide Running Clearance 0
76. nd secure with clamps 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 a Disconnect and ground spark plug leads b Close choke on carburetor c Crank engine several times d Remove spark plug and check for fuel at tip Condition 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 3 Check operation of fuel pump a Remove fuel line from inlet fitting of carburetor b Crank engine several times and observe flow 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 fuel 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 24 690 37 Rev B KohlerEngines com 21 Fuel System
77. ne Other than periodically checking replacing spark plugs no maintenance or timing adjustments i Da o POOR 1657 are necessary or possible Mechanical systems do Chalky white deposits indicate very high combustion occasionally fail or break down Refer to Troubleshooting temperatures This condition is usually accompanied to determine root of a reported problem by excessive gap erosion Lean carburetor settings an intake air leak or incorrect spark timing are normal causes for high combustion temperatures Reported ignition problems are most often due to poor connections Before beginning test procedure check all external wiring Be certain all ignition related wires BATTERY are connected including spark plug leads Be certain all A 12 volt battery with 400 cold cranking amps cca is terminal connections fit snugly Make sure ignition switch generally recommended for starting in all conditions A is in run position smaller capacity battery is often sufficient if an application is started only in warmer temperatures Refer to following table for minimum capacities based on anticipated ambient temperatures Actual cold cranking requirement 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 Temperature Battery Required Above 32
78. nected or grounded Do not crank engine or perform tests with 1 spark plug lead disconnected and not grounded or permanent system damage may occur 1 With engine stopped disconnect 1 spark plug lead Connect spark plug lead to post terminal of spark tester and attach tester clip to a good engine ground 2 Crank engine over establishing a minimum of 550 600 RPM and observe tester s for spark 3 Repeat spark test on opposite cylinder if cylinders are being tested individually Condition Possible Cause Conclusion Both cylinders have good spark but Spark Plug s Install new spark plug s and retest engine runs poorly or existing plug engine performance condition is questionable 1 cylinder has good spark and other Ignition Test ignition modules and cylinder has no or intermittent spark connections Spark on both cylinders but power is Sheared Flywheel Key Check for broken key suspect Check Ignition Modules and Connections 1 Remove blower housing from engine Inspect kill wire for any damage cuts or shorts to engine or ignition module body Check that connections are oriented properly on terminals of modules 2 On MDI adjustable timing engines ensure that both modules are correctly installed with flat side of module out towards you Condition Possible Cause Conclusion All checks are OK but module has no Ignition Module Replace affected module spark or fails to advance BATTERY CHARGING SYSTEM NOTE Obse
79. ngine speed with this system A typical ignition system consists of e 1 magnet assembly which is permanently affixed to flywheel e 2 electronic capacitive discharge ignition modules which mount on engine crankcase e 1 kill switch or key switch which grounds modules to stop engine e 2 spark plugs A Spark Plug s B Oil Pressure Switch C Oil Sentry Green D White Kill Flywheel Stator B Non Smart Spark Rectifier Regulator E Assembly F Ignition Module G Ignition H Connector Solenoid Shift Starter l Rectifier Regulator J Oil Sentry Kill Green K Violet B L Assembly M Starter Solenoid Tang N Starter Solenoid Stud O Fuse P Blue Q Aremalg Janition rail R White S Accessory Terminal T Yellow U Ignition Kill V Red Ww Carburetor X Carburetor Solenoid Oil Sentry Panel Y Black Ground Z Intake Manifold Screw AA Black AB Light Remote Light AC Oil Sentry Light AD Connector AE Magneto AF Key Switch AG Accessory AH Battery Al Starter AJ Ground AK Key Switch Ground AL Rectifier AM Blue Red AN Battery Positive AO Battery Negative Electronic Ignition Systems 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 h
80. nkshaft If teeth are badly worn chipped or some are missing replacement of crankshaft will be necessary Inspect crankshaft bearing surfaces for scoring grooving etc Measure running clearance between crankshaft journals and their respective bearing bores Use an inside micrometer or telescoping gauge to measure inside diameter of both bearing bores in vertical and horizontal planes Use an outside micrometer to measure outside diameter of crankshaft main bearing journals Subtract journal diameters from their respective bore diameters to get running clearances Check results against tolerances in Specifications If running clearances are within specification and there is no evidence of scoring grooving etc no further reconditioning is necessary If bearing surfaces are worn or damaged crankcase and or oil pan will need to be replaced Inspect crankshaft keyways If worn or chipped replacement of crankshaft will be necessary Inspect crankpin for score marks or metallic pickup Slight score marks can be cleaned with crocus cloth soaked in oil If wear limits as stated in Specifications are exceeded it will be necessary to either replace crankshaft or regrind crankpin to 0 25 mm 0 010 in undersize If reground a 0 25 mm 0 010 in undersize connecting rod big end must then be used to achieve proper running clearance Measure crankpin for size taper and out of round Connecting rod journal can be ground 1 size unde
81. oil function test and check for continuity Meter should indicate continuity Repeat test several times Condition Conclusion Solenoid fails to activate Replace solenoid No continuity is indicated Plunger fails to stay retracted 40 KohlerEngines com 24 690 37 Rev B Disassembly Inspection and Service A WARNING Accidental Starts can cause severe injury or death Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery Disconnect and ground spark plug lead s before servicing B External Engine Components 7 D f 4 f PISS M gt j g A ji N NSU A Guard B Blower Housing C Fuel Filter D Rectifier Regulator E Outer Baffle F Electric Starter G Inner Baffle H Air Cleaner I Air Cleaner Gasket J Support Bracket K Fuel Pump L Oil Cooler M O ring N Nipple o Oil Filter P Plastic Debris Screen Metal Debris Screen R Support Ring S Spacer T Fan Clean all parts thoroughly as engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow manufacturer s instructions and safety precautions carefully Make sure
82. ounting Screw 2 5 3 3 N m 22 29 in Ib 3 Values are in Metric units Values in parentheses are English equivalents 5 Lubricate threads with engine oil prior to assembly 24 690 37 Rev B KohlerEngines com 7 Specifications TORQUE SPECIFICATIONS CV682 CV732 CV742 CV752 Stator Mounting Screw 6 2 N m 55 in Ib Valve Cover Yellow O Ring Style Cover Fastener w Integral Metal Spacers 6 2 N m 55 in Ib CLEARANCE SPECIFICATIONS CV682 CV732 CV742 CV752 Camshaft End Play 0 076 0 127 mm 0 0030 0 0050 in Running Clearance 0 025 0 063 mm 0 0010 0 0025 in Bore I D New Max Wear Limit 20 000 20 025 mm 0 7874 0 7884 in 20 038 mm 0 7889 in Bearing Surface O D New Max Wear Limit 19 962 19 975 mm 0 7859 0 7864 in 19 959 mm 0 7858 in Connecting Rod Connecting Rod to Crankpin Running Clearance New Max Wear Limit 0 030 0 055 mm 0 0012 0 0022 in 0 070 mm 0 0028 in Connecting Rod to Crankpin Side Clearance 0 26 0 63 mm 0 0102 0 0248 in Connecting Rod to Piston Pin Running Clearance 0 015 0 028 mm 0 0006 0 0011 in Piston Pin End I D New Max Wear Limit 17 015 17 023 mm 0 6699 0 6702 in 17 036 mm 0 6707 in Crankcase Governor Cross Shaft Bore D New Max Wear Limit 8 025 8 075 mm 0 3159 0 3179 in 8 088 mm 0 3184 in Crankshaft End Play free 0
83. ove Inner Baffle and Breather Cover 1 Remove screws securing inner baffle to crankcase 2 Remove inner valley baffle 3 Remove remaining screws from breather cover 4 Remove breather cover and gasket Crankcase Breather System Breather system is designed to control amount of oil in head area and still maintain necessary vacuum in crankcase A spring steel reed and stop is mounted on each bank of crankcase between lifter bores When pistons move downward air is pushed past reeds into cylinder head cavities On cylinder 2 upper end of head is completely sealed by rocker cover so a low positive pressure is created in head cavity Cylinder 1 rocker cover has a hole in it for venting Bottom nipple of oil separator canister is fitted into hole with a grommet From top nipple of canister a breather hose goes back to air cleaner base Air moving into cylinder 1 head cavity is filtered through oil separator and then is drawn into air intake Upward travel of pistons closes reeds and creates a low vacuum in lower crankcase A combination of low pressure above and low vacuum below forces any accumulated oil out of cylinder 2 head area into crankcase On cylinder 1 bank you have atmospheric pressure above and vacuum below again drawing any oil toward crankcase Remove Valve Covers 1 Remove screws securing each valve cover Note valve cover differences for proper location in reassembly 2 Remove valve covers and O rings
84. per with governor setting Overspeed is hazardous and could cause personal injury Initial Adjustment Procedure Make this adjustment whenever governor arm is loosened or removed from cross shaft Adjust as follows 1 2 3 4 Make sure throttle linkage is connected to governor arm and throttle lever on carburetor Loosen nut holding governor lever to cross shaft Move governor lever toward carburetor as far as it will go wide open throttle and hold in this position Insert a long thin rod or tool into hole on cross shaft and rotate shaft counterclockwise viewed from end as far as it will turn then torque nut to 6 8 N m 60 in Ib Sensitivity Adjustment Governor sensitivity is adjusted by repositioning governor spring in holes of governor lever If speed surging occurs with a change in engine load governor is set too sensitive If a big drop in speed occurs when normal load is applied governor should be set for greater sensitivity Adjust as follows 1 2 To increase sensitivity move spring closer to governor lever pivot point To decrease sensitivity move spring away from governor lever pivot point KohlerEngines com 27 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 a
85. 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 e Breather reed broken e Clogged broken or inoperative crankcase breather e Loose or improperly torqued fasteners e Piston blow by or leaky valves e Restricted exhaust 24 690 37 Rev B 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 Check for buildup of dirt and debris on crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas can cause overheating Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or inoperative breather worn or d
86. proper valve seat angle 44 5 half of full 89 angle will achieve desired 0 5 1 0 full cut interference angle where maximum pressure occurs on outside diameters of valve face and seat Lapping Valves NOTE Exhaust valves that are black in color cannot be ground and do not require lapping Reground or new valves must be lapped in to provide proper fit Use a hand valve grinder with a suction cup for final lapping Lightly coat valve face with a fine grade of grinding compound then rotate valve on its seat with grinder Continue grinding until a 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 SAE 10 oil to prevent rusting Intake Valve Stem Seal These engines use valve stem seals on intake valves Always use a new seal when valves are removed from cylinder head Seals should also be replaced if deteriorated or damaged in any way Never reuse an old seal Hydraulic Lifters Inspection Check base surface of hydraulic lifters for wear or damage If lifters need to be replaced apply a liberal coating of Kohler lubricant to base of each new lifter before it is installed Bleeding Lifters To prevent a possible bent push rod or broken rocker arm it is important to bleed any excess oil out of lifters before they are installed 1 Cut a 50 75 mm 2 3 in piece from end of
87. r 1 Install starter motor using screws Position lift bracket to also secure dipstick tube Torque screws to 15 3 N m 135 in Ib Connect leads to solenoid Install dipstick tube and align mounting hole with threaded hole in lift bracket Secure with M5 screw Torque screw to 4 0 N m 35 in Ib 64 KohlerEngines com 24 690 37 Rev B Install Fuel Pump A WARNING Explosive Fuel can cause fires and severe burns lj 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 Fuel Pump Components Reassembly 2 Some engines have an evap connector fitting on the air cleaner housing If this was removed secure fitting to housing with hi lo screw Torque screw to 2 1 N m 19 in lb 3 Install air cleaner assembly and any clips onto mounting studs Secure with hex flange nuts Torque nuts in 2 stages first to 7 3 N m 65 in Ib then finally to 8 2 N m 73 in lb using sequence shown 4 Install 2 screws securing support bracket to air cleaner assembly Torque screws to 7 9 N m 70 in Ib 5 Connect breather hose to air cleaner In
88. r 1 Insert rubber stopper into oil fill hole Be sure pinch clamp is installed on hose and use tapered adapters to connect hose between stopper and one manometer tube Leave other tube open to atmosphere Check that water level in manometer is at 0 line Make sure pinch clamp is closed 2 Start engine and run no load high speed 3 Open clamp and note water level in tube Level in engine side should be a minimum of 10 2 cm 4 in above level in open side If level in engine side is less than specified low no vacuum or level in engine side is lower than level in open side pressure check for conditions in table below 4 Close pinch clamp before stopping engine Condition To test crankcase vacuum with vacuum pressure gauge 1 Remove dipstick or oil fill plug cap 2 Install adapter into oil fill dipstick tube opening upside down over end of a small diameter dipstick tube or directly into engine if a tube is not used Insert barbed gauge fitting into hole in stopper 3 Run engine and observe gauge reading Analog tester needle movement to left of 0 is a vacuum and movement to right indicates a pressure Digital tester depress test button on top of tester Crankcase vacuum should be a minimum of 10 2 cm 4 in of water If reading is below specification or if pressure is present check table below for possible causes and conclusions Conclusion Crankcase breather clogged or inoperative NOTE If b
89. r When grinding crankshaft grinding stone deposits can get caught in oil passages which could cause severe engine damage Removing crankpin plug when crankshaft is ground provides easy access for removing any grinding deposits collected in oil passages Use following procedure to remove and replace plug Procedure to Remove Crankshaft Plug 1 Drill a 3 16 hole through plug in crankshaft 2 Thread a 3 4 or 1 long self tapping screw with a flat washer into drilled hole Flat washer must be large enough to seat against shoulder of plug bore 3 Tighten self tapping screw until it draws plug out of crankshaft Procedure to Install New Plug Use 1 single cylinder camshaft pin as a driver and tap plug into plug bore until it seats at bottom of bore Make sure plug is tapped in evenly to prevent leakage 52 KohlerEngines com Remove Flywheel End Oil Seal Remove oil seal from crankcase Crankcase Inspection and Service Check all gasket surfaces to make sure they are free of gasket fragments Gasket surfaces must also be free of deep scratches or nicks Check cylinder bore for scoring In severe cases unburned fuel can cause scuffing and scoring of cylinder wall It washes necessary lubricating oils off piston and cylinder wall As raw fuel seeps down cylinder wall piston rings make metal to metal contact with wall Scoring of cylinder wall can also be caused by localized hot spots resulting from blocked cooling fins or
90. r broken insulation Starter Switch By pass switch or solenoid with a jumper wire If starter cranks or Solenoid normally replace faulty components Remove and perform individual solenoid test procedure Starter energizes but turns Battery Check specific gravity of battery If low recharge or replace slowly battery as necessary 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 or Engine Make sure clutch or transmission is disengaged or placed 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 24 690 37 Rev B KohlerEngines com 37 Starter System SOLENOID SHIFT ELECTRIC STARTERS Solenoid Shift Starter Components A Tube B Washer C Armature D Drive E Stop F Retaining Ring G Collar H Drive End Cap I Screw J Plunger K Spring L Lever M Plate N Plug o Solenoid P Frame and Field Q Brush Holder R Nut s Commutator End T Screw Plate U Bolt When power is applied to starter electric solenoid moves drive pinion out onto drive shaft and into mesh with flywheel ring gear When pinion reaches end of drive shaft it rotates
91. re voltage from B lead to ground using a DC voltmeter Condition Conclusion Voltage is 14 7 volts or less Charging system is OK Battery is unable to hold charge service or replace Voltage is more than 14 7 volts Faulty rectifier regulator replace KohlerEngines com 24 690 37 Rev B Starter System NOTE Do not crank engine continuously for more than 10 seconds Allow a 60 second cool down period between starting attempts Failure to follow these guidelines can burn out starter motor NOTE If engine develops sufficient speed to disengage starter but does not keep running a false start engine rotation must be allowed to come to a complete stop before attempting to restart engine 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 solenoid shift 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 o
92. reather Oil Pan Oil Reservoir Piston Components if 4 A Oil Fill Dipstick B Dipstick Tube C Oil Seal D Breather Gasket E Breather Cover F Flat Washer G Breather Reed H Governor Cross Shaft I Oil Pan Gasket J Piston Ring Retainer K Piston Pin L Piston M Piston Ring Set N Connecting Rod Connecting Rod End o Cap P Camshaft Locking Tab Thrust Q Governor Gear R Washer S Oil Pan T Oil Screen U Ball V Spring Oil Pump Cover Ww O ring X Outer Gerotor Gear Y Oil Pump Assembly Z Crankshaft 54 KohlerEngines com NOTE Make sure engine is assembled using all specified torgue values tightening seguences and clearances Failure to observe specifications could cause severe engine wear or damage 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 Make sure all traces of any cleaner are removed before engine is assembled and placed into operation Even small amounts of these cleaners can guickly break down lubricating properties of engine oil Check oil pan crankcase cylinder heads and valve covers to be certain that all old sealing material has been removed Use gasket remover lacguer thinner or paint remover to remove any remaining traces Clean surfaces with isopropyl alcohol acetone lacguer thinner or electrical contact cleaner Install Flywheel End Oil Seal 1 Make
93. reather 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 torgue fasteners Replace all worn or damaged seals and gaskets Make sure all fasteners are tightened securely Use appropriate torgue valves and seguences when necessary Piston blow by or leaky valves confirm by inspecting components Restricted exhaust Recondition piston rings cylinder bore valves and valves guides 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 24 690 37 Rev B Troubleshooting COMPRESSION TEST For Command Twins Acompression 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 It is difficult to obtain an accurate compression reading because of ACR mechanism As an alternative use cylinder leakdown test described below CYLINDER LEAKDOWN TES
94. rque shorter M5 side baffle screws to 4 0 N m 35 in Ib Torque M5 side baffle screws into cylinder head to 6 2 N m 55 in Ib in a new hole or to 4 0 N m 35 in Ib in a used hole Torque two lower M6 baffle mounting screws to 10 7 N m 95 in Ib in a new hole or to 7 3 N m 65 in Ib in a used hole 5 Torque four breather cover screws to 7 3 N m 65 in Ib in sequence shown Install Flywheel Fan and Debris Screen A CAUTION Failure to utilize or reassemble debris screen as designed could result in debris screen Jo failure and serious personal injury 9 Plastic Debris Screen NOTE Position locating tabs on back of fan in recesses of flywheel 1 Install fan onto flywheel using screws 2 Torque screws to 9 9 N m 88 in Ib 3 Place plastic debris screen on fan and secure with screws Torque screws to 2 2 N m 20 in Ib 4 Install guard and secure with screws Metal Debris Screen NOTE Position locating tabs on back of fan in recesses of flywheel 1 Position fan on flywheel 2 Install a spring washer on stepped end of each spacer with concave side down toward fan Insert spacers with spring washers into fan Place support ring on spacers Set metal debris screen on support 3 Install a plain washer on each screw then apply Loctite 242 to screw threads M6 and insert into screen support ring spacer spring washer fan Torque screws to 9 9 N m 88 in Ib 4 Ins
95. rts Do not use metal tools or wire to clean orifices and jets Inspect and thoroughly check carburetor for cracks wear or damage Inspect fuel inlet seat for wear or damage Check spring loaded choke plate to make sure it moves freely on shaft 15 Clean carburetor fuel bowl as required including accelerator jet feed hole and check valve in bottom of bowl 16 Install new diaphragm assembly with outer lip resting in groove of pump base Install new spring on top of diaphragm center plate Reinstall cover and secure with new screws Torque screws to 1 1 4 N m 8 12 in Ib Reinstall solenoid using new gasket and torque solenoid to 3 4 5 6 N m 30 50 in Ib 17 Reinstall main nozzles assemblies and slow jets in their respective sides 18 Attach new inlet needle into metal hinge of float Groove near top of needle slides into formed fork 19 Install float and inlet needle down into seat and carburetor body With float hinge held in between body mounting legs insert new pivot pin through float hinge and into opposite hole 20 Invert carburetor body as shown and measure dimension between top of float and top of gasket float rib on body Correct float setting is 1 6 mm 0 063 in 0 5 mm 0 02 in 21 If float height adjustment is required a small flat blade screwdriver can be used to pry tab up from side or pry tab down on end 22 When proper float height is obtained carefully reinstall fuel bowl using new bowl
96. rushes brush holder assembly a Carefully unhook retaining caps from brush assemblies Do not lose springs KohlerEngines com 39 Starter System b Position brushes back in their slots so they are flush with I D of brush holder assembly Insert brush installation tool with extension or use tube described above from a prior brush installation through brush holder assembly so holes in metal mounting clips are up out c Install brush springs and snap on retainer caps d Hold starter assembly vertically on end housing and carefully place tool with extension and assembled original brush holder assembly onto end of armature shaft Slide brush holder assembly down into place around commutator install positive brush lead grommet in cutout of frame 11 Install end cap onto armature and frame aligning thin raised rib in end cap with corresponding slot in grommet of positive brush lead 12 Install thru bolts and brush holder mounting screws Torque bolts to 5 6 9 0 N m 49 79 in Ib and brush holder mounting screws to 2 5 3 3 N m 22 29 in Ib 13 Hook plunger behind upper end of drive lever and install spring into solenoid Insert mounting screws through holes in drive end cap Use these to hold solenoid gasket in position then mount solenoid Torque screws to 4 0 6 0 N m 35 53 in Ib 14 Connect positive brush lead bracket to solenoid and secure with nut Torque nut to 8 11 N m 71 97 in Ib Do not ov
97. 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 equipment 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 equipped with a 15 or 20 amp regulated charging system Some have a 25 amp regulated charging system 15 20 25 Amp Regulated Charging System Stator Stator is mounted on crankcase behind flywheel Follow procedures in Disassembly and Reassembly if stator replacement is necessary Rectifier Regulator NOTE When installing rectifier regulator take note of terminal markings and install plug s accordingly NOTE Disconnect all electrical connections attached to rectifier regulator Testing may be performed with rectifier regulator mounted or loose Repeat applicable test procedure 2 or 3 times to determine condition of part Rectifier regulator is mounted on blower housing To replace it disconnect plug s remove two mounting screws and ground wire or metal grounding strap Testing of rectifier regulator may be performed as follows using appropriate Rectifier Regulator Tester To test 15 amp rectifier regulators 1 Connect tester ground lead with spring cl
98. s are shown in following photos Normal R al L 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 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 24 690 37 Rev B Electrical System Carbon Fouled ELECTRONIC IGNITION SYSTEMS Ignition System Components Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich Sd f Kill Switch carburetion weak ignition or poor compression A off Position of Air Gap Overheated Key Switch C Flywheel Magnet E Spark Plug F Ignition Modules There are 2 different types of ignition systems used on these engines All systems use an ignition module which energizes spark plug Difference in systems is in way ignition timing is triggered Both ignition systems are designed to be trouble free for life of engi
99. seal installer Remove Connecting Rods with Pistons and Rings NOTE If a carbon ridge is present at top of either cylinder bore use a ridge reamer tool to remove it before attempting to remove piston NOTE Cylinders are numbered on crankcase Use numbers to mark each end cap connecting rod and piston for reassembly Do not mix end caps and connecting rods 1 Remove screws securing closest connecting rod end cap Remove end cap 2 Carefully remove connecting rod and piston assembly from cylinder bore 3 Repeat above procedure for other connecting rod and piston assembly KohlerEngines com 49 Disassembly Inspection and Service Piston and Rings Piston and Rings Components and Details Top Compression A Piston B Ring Middle Compression C Ring D Rails Oil Control Ring E Expander F 3 Piece Inspection 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 Scuffing and scoring of pistons and cylinder walls occurs when internal engine 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 pi
100. see Tools and Aids to hold flywheel and loosen screw securing flywheel to crankshaft 2 Remove screw and washer 3 Use a puller to remove flywheel from crankshaft 4 Remove woodruff key from crankshaft Inspection Inspect flywheel for cracks and flywheel keyway for damage Replace flywheel if it is cracked Replace flywheel crankshaft and key if flywheel key is sheared or keyway is damaged Inspect ring gear for cracks or damage Kohler does not provide ring gears as a serviceable part Replace flywheel if ring gear is damaged Remove Stator and Backing Plates 1 Remove screws securing backing plate Remove backing plate 2 Remove screws and stator Note position routing of stator lead KohlerEngines com 47 Disassembly Inspection and Service Breather Oil Pan Oil Reservoir Piston Components Oil Fill Dipstick A B Dipstick Tube C Oil Seal D Breather Gasket E Breather Cover F Flat Washer G Breather Reed H Governor Cross Shaft I Oil Pan Gasket J Piston Ring Retainer K Piston Pin L Piston M Piston Ring Set N Connecting Rod Connecting Rod End o Cap P Camshaft Locking Tab Thrust Q Governor Gear R Washer S Oil Pan T Oil Screen U Ball V Spring Oil Pump Cover Ww O ring X Outer Gerotor Gear Y OilPumpAssembly Z Crankshaft 48 KohlerEngines com Remove Oil Pan Assembly 1 Remove screws securing oil pan to crankcase 2 Locate splitting
101. stall Muffler 1 Install port liners if equipped Install muffler and attaching hardware to muffler bracket Torque screws to 9 9 N m 88 in Ib 2 Install hex flange nuts to exhaust studs Torque nuts to 24 4 N m 216 in lb Install Oil Cooler if equipped A Outlet Fuel Line B Pulse Line C Crankcase Fitting D Inlet Fuel Line E Fuel Filter F Fuel Pump NOTE If anew fuel pump is being installed make sure orientation of new pump is consistent with removed pump Internal damage may occur if installed incorrectly 1 Install fuel pump and lines as an assembly Connect pulse line to crankcase vacuum fitting 2 Install fuel pump using screws Torque screws to 2 3 N m 20 in Ib 3 Connect fuel lines Install Air Cleaner Assembly Torque Sequence 1 Install a new air cleaner gasket Make sure all holes align and are open 24 690 37 Rev B 1 Secure adapter to oil pan with oil filter nipple Torque oil filter nipple to 27 N m 20 ft Ib 2 Install screws and secure oil cooler to blower housing Install Oil Filter and Fill Crankcase with Oil NOTE Make sure that both oil drain plugs are installed and torqued to specifications to prevent oil leakage 1 Install oil drain plug s Torque plug s to 13 6 N m 10 ft Ib If oil drain valve is used make sure valve body is closed and cap is on 2 Place new filter in shallow pan with open end up Fill
102. ston boss piston pin area If original piston and connecting rod can be reused after new rings are installed original pin can also be reused but new piston pin retainers are required Piston pin is included as part of piston assembly if pin boss in piston 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 Scratches on rings and pistons are caused by abrasive material such as carbon dirt or pieces of hard metal 50 KohlerEngines com Detonation damage occurs when a portion of fuel charge ignites spontaneously from heat and pressure shortly after ignition This creates 2 flame fronts which meet and explode to create extreme hammering pressures on a specific area of piston Detonation generally occurs from using low octane fuels Preignition or ignition of fuel charge before timed spark can cause damage similar to detonation Pr
103. t only if it is damaged After removing damaged shaft press or lightly tap replacement shaft into oil pan to depth shown Reassembly 1 Install locking tab thrust washer on governor gear shaft with tab down 2 Position regulating pin within governor gear flyweight assembly and slide both onto governor shaft Oil Pump Assembly Oil pump is mounted inside oil pan If service is required continue with Disassembly Inspection and Reassembly Disassembly 1 Remove screws 2 Lift oil pump assembly from oil pan Remove outer gerotor gear from oil pan 3 Ensure ball and spring remain installed in pressure relief hole of oil pan If ball and spring fall out of pressure relief hole see reassembly for correct installation 4 Remove oil pump cover O ring from groove in oil pan Inspection Inspect oil pump housing gear and rotors for nicks burrs wear or any visible damage Inspect oil pump cover O ring for cuts nicks or any visible damage If any parts are worn or damaged replace oil pump assembly and or O ring Check oil pickup screen for damage or restriction replace if necessary Reassembly 1 Lubricate outer gerotor gear with oil Install outer gerotor gear through shaft of oil pump around inner gerotor gear Matching molding dots on inner and outer gerotor gears is not necessary and will not affect oil pump efficiency 2 Reinstall ball then spring into pressure relief hole in oil pan 3 Reinstall O
104. t low speeds and high operating temperatures A pressure relief valve limits maximum pressure of system Oil pan must be removed to service oil pickup pressure relief valve and oil pump Lubrication Components f T t iy wih il oy M A Oil Fill Dipstick B Oil Fill Tube C Back Side D Oil Filter E Nipple F Oil Cooler G O ring H Oil Drain Plug I Oil Sentry OIL RECOMMENDATIONS Refer to Maintenance CHECK OIL LEVEL NOTE To prevent extensive engine wear or damage never run engine with oil level below or above operating range indicator on dipstick Ensure engine is cool Clean oil fill dipstick areas of any debris 1 Remove dipstick wipe oil off 2 Reinsert dipstick into tube rest cap on tube do not thread cap onto tube 3 Remove dipstick check oil level Level should be at top of indicator on dipstick 4 If oil is low on indicator add oil up to top of indicator mark 5 Reinstall dipstick and tighten securely 28 KohlerEngines com CHANGE OIL AND FILTER Change oil while engine is warm 1 Clean area around oil fill cap dipstick drain plug oil drain valve a Remove drain plug and oil fill cap dipstick Allow oil to drain completely or b Open oil drain valve cap if needed attach a length of 1 2 in I D hose to direct oil into appropriate container twist valve drain body counterclockwise and pull Remove dipstick Allow oil to drain
105. tabs cast into perimeter of oil pan Insert drive end of a 1 2 breaker bar between splitting tab and crankcase and turn it to loosen seal Do not pry on sealing surfaces as this can cause leaks Inspection Inspect oil seal in oil pan and remove it if it is worn or damaged Refer to Install Oil Seal in Oil Pan in Reassembly for new oil seal installation Inspect main bearing surface for wear or damage refer to Specifications Replace oil pan assembly if required Governor Gear Assembly Governor Shaft Component and Details 34 0 mm 1 3386 in p 33 5 mm 1 3189 in 19 40 mm 0 7638 in C Gear Shaft Governor gear assembly is located inside oil pan If service is required refer to Inspection Disassembly and Reassembly procedures Inspection Inspect governor gear teeth Replace gear if it is worn chipped or if any teeth are missing Inspect governor weights They should move freely in governor gear Disassembly NOTE Governor gear is held onto shaft by small molded tabs in gear When gear is removed from shaft these tabs are destroyed and gear must be replaced Therefore remove gear only if absolutely necessary Governor gear must be replaced once it is removed from oil pan 24 690 37 Rev B 1 Remove regulating pin and governor gear assembly 2 Remove locking tab thrust washer located under governor gear assembly 3 Carefully inspect governor gear shaft and replace i
106. tall guard and secure with screws KohlerEngines com 61 Reassembly Install Oil Sentry if equipped 1 Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads of Oil Sentry switch and install it into breather cover Torque to 4 5 N m 40 in Ib 2 Connect wire lead green to Oil Sentry terminal Install Control Panel 1 Assemble choke lever to control bracket 2 Install control panel to blower housing 3 Assemble throttle control shaft to control bracket Secure throttle shaft bracket with screws to cylinder head 4 Connect choke control cable and throttle control cable to control bracket Reconnect Rectifier Regulator 1 Install rectifier regulator in blower housing if removed previously then connect rectifier regulator ground lead with washer and green screw through eyelet If a grounding bracket is used secure with mounting screw and washer against outer side of rectifier regulator 2 Install B terminal lead into center position of rectifier regulator plug and connect plug to rectifier regulator 62 KohlerEngines com Install Valve Covers Torque Sequence 1 Make sure sealing surfaces are clean 2 Make sure there are no nicks or burrs on sealing surfaces 3 Install a new O ring in groove of each cover 4 Position covers on cylinder heads Locate cover with oil separator hole on cylinder 1 Install four screws in ea
107. ured With Screws 1 Check to make sure there are no nicks or burrs on sealing surfaces of cylinder head or crankcase 2 Install a new cylinder head gasket with printing up 3 Install cylinder head and start four screws 4 Torque screws in two stages first to 22 6 N m 200 in Ib then finally to 41 8 N m 370 in Ib following sequence shown Heads Secured With Mounting Studs Nuts and Washers 1 Check to make sure there are no nicks or burrs on sealing surfaces of cylinder head or crankcase 2 If all studs were left intact go to Step 6 If any studs were disturbed or removed install new studs as described in Step 3 Do not use reinstall any loosened or removed studs 3 Install new mounting stud s into crankcase a Thread and lock 2 mounting nuts together on smaller diameter threads b Thread opposite end of stud with preapplied locking compound into crankcase until specified height from crankcase surface is achieved When threading in studs use a steady tightening motion without interruption until proper height is obtained Otherwise frictional heat from engaging threads may cause locking compound to set up prematurely Studs closest to lifters must have an exposed height of 75 mm 2 15 16 in Studs furthest from lifters must have an exposed height of 68 mm 2 3 4 in c Remove nuts and repeat procedure as required 4 Check that dowel pins are in place and install a new cylinder head gasket
108. uretor throttle linkage and linkage spring can be separated Reattach bushings to linkage following separation to avoid losing them Remove External Governor Controls Loosen nut and remove governor lever from cross shaft Remove Electric Starter Motor 1 Disconnect leads from starter 2 Remove screws and starter assembly Remove Outer Baffles Debris Screen and Blower Housing 1 Disconnect plug from rectifier regulator Use tip of small flat tool to bend locking tang then remove B terminal from center position in plug 2 Rectifier regulator does not have to be detached from blower housing 3 Remove screws securing outer baffles Note location of any lifting strap and position of short screws one each side on bottom for reassembly 4 Remove outer baffles 5 Remove fixed guard from blower housing If flywheel screen overlaps blower housing remove fasteners and screen If it is a metal debris screen with long bolts also remove remaining loose hardware Remove spacers paying attention to curvature of spring washers between spacers and fan 6 Remove remaining screws securing blower housing Note 1 green plated screw used for rectifier regulator ground strap or lead Oil separator can remain on blower housing but remove from valve cover Remove blower housing 7 Remove cooling fan 24 690 37 Rev B 1 Disconnect lead from Oil Sentry switch 2 Remove Oil Sentry switch from breather cover Rem
109. 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 800 664 298 1 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 cylinder 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
110. ve wear or damage Be certain pistons and connecting rods are assembled exactly as shown NOTE Align chamfer of connecting rod with chamfer of its mating end cap When installed flat faces of connecting rods should face each other Faces with raised rib should be toward outside 1 If piston rings were removed see Disassembly Inspection and Service procedure to install new rings 2 Lubricate cylinder bore piston and piston rings with engine oil Compress rings using a piston ring compressor 3 Lubricate crankshaft journals and connecting rod bearing surfaces with engine oil 4 Make sure FLY stamping on piston is facing towards flywheel side of engine Use a hammer with a rubber grip and gently tap piston into cylinder Be careful that oil ring rails do not spring free between bottom of ring compressor and top of cylinder 5 Install inner rod cap to connecting rod using screws Torque in increments to 13 6 N m 120 in Ib Illustrated instructions are provided in service rod package 6 Repeat above procedure for other connecting rod and piston assembly 24 690 37 Rev B 1 Liberally apply camshaft lubricant to each cam lobe Lubricate camshaft bearing surfaces of crankcase and camshaft with engine oil 2 Position timing mark of crankshaft gear at 12 o clock position 3 Turn governor cross shaft clockwise until lower end of shaft contacts cylinder Make sure cross shaft remains in this position while insta
111. with Oil Sentry installation hole is sealed with a 1 8 27 N P T F pipe plug Installation 1 Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to threads of switch 2 Install switch into tapped hole in breather cover 3 Torque switch to 4 5 N m 40 in Ib Testing Compressed air a pressure regulator pressure gauge and a continuity tester are required to test switch Normally Closed Switch 1 Connect continuity tester across blade terminal and metal case of switch With O psi pressure applied to switch 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 Normally Open Switch 1 Connect continuity tester across blade terminal and metal case of switch With O psi pressure applied to switch tester should indicate no continuity switch open 2 Gradually increase pressure to switch As pressure increases through range of 2 5 psi tester should indicate a change to continuity switch closed Switch should remain closed as pressure is increased to 90 psi maximum 3 Gr
112. with compressed air Remove low idle fuel adjusting needle Clean vent ports and air bleeds Blow out all passages with compressed air Engine runs lean indicated by misfiring loss of speed and power governor hunting or excessive throttle opening Float level is set too low Adjust float according to Float Replacement Procedure Idle holes plugged dirt in fuel delivery channels Remove low idle fuel adjusting needle Clean main fuel jet and all passages blow out with compressed air Fuel leaks from carburetor Float level is set too high Adjust float according to Float Replacement Procedure Dirt under fuel inlet needle Remove needle clean needle and seat and blow with compressed air Bowl vents plugged Carburetor bowl gasket leaks Blow out with compressed air Replace gasket 24 690 37 Rev B KohlerEngines com 23 Fuel System Fuel Shut Off Solenoid Carburetor Adjustments Carburetors are equipped 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 o
113. 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 oil 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 KohlerEngines com 65 Reassembly Connect Spark Plug Leads Connect leads to spark plugs Prepare Engine for Operation Engine is now completely reassembled Before starting or operating engine be sure to do following 1 Make sure all hardware is tightened securely 2 Make sure oil drain plugs Oil Sentry pressure switch and a new oil filter are installed 3 Adjust carburetor idle speed adjusting screw as necessary Testing Engine It is recommended that engine be operated on a test stand or bench prior to installation in piece of equipment 1 Set engine up on a test stand Install an oil pressure gauge Start engine and check to be certain that oil pressure 20 psi or more is present Run engine at idle for 2 3 minutes then 5 6 minutes more between idle and midrange Adjust carburetor mixture settings as necessary as available 2 Adjust idle speed screw and high speed stop as necessary Make sure maximum engine speed does not exceed 3750 RPM no load 66 KohlerEngines com 24 690 37 Rev B 24 690 37 Rev B Kohl

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