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CH18, CH20, CH23, CH25, CH640, CH730, CH740 Service Manual

1. we Tre B 8mm Step Down 147 Nm 1301 10 24 690 30 Rev D Reassembly 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 extensive 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 If piston rings were removed see Disassembly Inspection and Service procedure to install new rings Lubricate cylinder bore piston and piston rings with engine oil Compress rings of piston 1 using a piston ring compressor Lubricate crankshaft journals and connecting rod bearing surfaces with engine oil 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 oil ring rails do not spring free between bottom of ring compressor and top of cylinder Install inner rod cap to connecting rod using screws Three different types of connecting rod bolts have been used and each has a different torque value If 8 mm
2. C Hde2 D XHoe3 E Holes 24 690 30 Rev D KohlerEngines com 83 Reassembly Install Control Panel if equipped 1 Install panel to blower housing 2 Connect throttle control cable or shaft 3 Connect choke control cable to control bracket 4 Connect Oil Sentry indicator light wires Install Valve Covers Torque Sequence NOTE Do not scrape old RTV sealant if used off sealing surface of cylinder head as this could cause damage and result in leaks Use of gasket remover solvent paint remover is recommended Three valve cover designs have been used First type used a gasket and RTV sealant between cover and sealing surface of cylinder head Second type had a black O ring installed in a groove on underside of cover and may have metal spacers in bolt holes Latest design uses a yellow or brown O ring with bolt hole spacers molded in place Tightening torque differs between gasket and O ring style covers Kits are available for converting to latest O ring type covers Differences are pointed out in following installation steps 1 If using gasket or sealant type cover prepare sealing surfaces of cylinder head and cover refer to Tools and Aids for approved sealants Always use fresh sealant Using outdated sealant could result in leakage With O ring type covers make sure sealing surfaces are clean 2 Make sure there are no nicks or burrs on sealing surfaces 3 For covers requiring RTV sealan
3. 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 If problem persists check for timing advance DSAI and Smart Spark only 1 cylinder has good spark and other Ignition Test ignition modules and cylinder has no or intermittent spark connections DSAI and Smart Spark only Spark on both cylinders but power is Timing Advance Check for timing advance DSAl and suspect Smart Spark only m Timing Advance DSAI and Smart Spark only Make a line near edge of flywheel screen with a marking pen chalk or narrow tape 5 Connect an automotive timing light to cylinder that had good spark 3 Run engine at idle and use timing light beam to locate line on screen Draw a line on blower housing next to line on screen Accelerate to full throttle and watch for movement of line on screen relative to line on blower housing If both cylinders had good spark repeat test on other cylinder Condition Possible Cause Conclusion Line on screen did not move away Ignition Test ignition modules and from line on blower housing during connections acceleration Lines made on blower Fe o not 90 rr iic i Test Ignition Modules and Connections DSAI only 1 Remove blower housing from engine
4. 52 KohlerEngines com 4 Install insulating bushing on stud terminal of new positive brushes Install stud terminal into commutator end cap Secure stud with fiber washer and screw 5 Install brush holder new negative brushes and self tapping screws 6 Install brush springs and brushes into pockets in brush holder Make sure chamfered sides of brushes are away from brush springs Style B Starters with style B end caps have brushes in a plastic carrier housing separate from end cap Replacement brushes come preassembled in carrier housing retained with two carton staples Commutator Service Clean commutator with a coarse lint free cloth Do not use emery cloth If commutator is badly worn or grooved turn it down on a lathe or replace starter Starter Reassembly 1 Place thrust washer if equipped over drive shaft of armature 2 Insert armature into starter frame Make sure magnets are closer to drive shaft end of armature Magnets will hold armature inside frame 3 Install drive end cap over drive shaft Make sure match marks on end cap and starter frame are aligned 4 Style A commutator end caps Install brush holder tool to keep brushes in pockets of commutator end cap Align match marks on commutator end cap and starter frame Hold drive end and commutator end caps firmly to starter frame Remove brush holder tool Style B commutator end caps If brush assembly is not being replaced
5. DLA must initialize fully extend to move throttle plate to closed position and partially open for starting Correct adjustment of DLA is critical to achieve full range of throttle plate movement See Adjustment Governor control unit GCU senses engine speed by pulse voltage inputs from ignition modules GCU regulates engine speed by variable input voltage from a customer supplied potentiometer or a single pole single throw SPST switch NOTE Actual speeds depend on application Refer to equipment manufacturer s recommendations Potentiometer Specifications SPST Switch Specifications Ope LowSpeedEndpont 24 690 30 Rev D Governor System GCU Safety Features In event of an engine overspeed condition GCU will shut down engine by grounding ignition modules GCU will shut down engine by grounding ignition when power to GCU is lost Linkage Throttle linkage spring will fully open throttle plate if linkage becomes detached from DLA This will create an overspeed condition causing engine to shut down DLA shaft will have to be manually screwed back into body and then retracted before reassembling linkage Adjustment DLA must be in fully retracted position during assembly Full range of throttle plate movement will not be achieved if DLA is partially extended when assembled Loosen DLA mounting plate screws located on top of actuator plate With throttle linkage centered in U Clip or secured with a reta
6. Carburetor E Vacuum Line 24 690 30 Rev D Electronic Throttle Vaporizer G Fullne Regulator Regulator Bracket Fuel System FUEL RECOMMENDATIONS Refer to Maintenance FUEL LINE Low permeation fuel line must be installed on carbureted Kohler Co engines to maintain EPA and CARB regulatory compliance I d T amp Hose Clamp Electric Lock Off Filter KohlerEngines com 21 Fuel System A WARNING IMPCO Carburetor Components Explosive Fuel can cause fires and severe burns If a gaseous odor is detected ventilate area and contact an authorized service technician LPG is extremely flammable and is heavier than air and tends to settle in low areas where a spark or flame could ignite gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area NG is extremely flammable is lighter than air and rises Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area To ensure personal safety installation and repair of LPG NG fuel supply systems must be performed only by qualified LPG NG system technicians Improperly installed and maintained LPG NG equipment could cause fuel supply system or other components to malfunction causing gas leaks Observe federal state and local laws governing LPG NG fuel storage and systems
7. or poor compression Overheated sunt a Chalky white deposits indicate very high combustion temperatures This condition is usually accompanied by excessive gap erosion Lean carburetor settings an intake air leak or incorrect spark timing are normal causes for high combustion temperatures BATTERY A 12 volt battery with 400 cold cranking amps cca is generally recommended for starting in all conditions A smaller capacity battery is often sufficient if an application is started only in warmer temperatures 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 Above 32 F 0 C OFF to 32 F 18 C to 0 C SPF to 0 F 21 C to 18 C 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 30 Rev D Electrical System ELECTRONIC IGNITION SYSTEMS Ignition System Components Kill Switch Off Position of Key Switch Flywheel D Magnet E Spark Plug F Ignition Modules There are 3 different
8. 0 063 mm 0 0010 0 0025 in Bore I D New 20 000 20 025 mm 0 7874 0 7884 in Max Wear Limit 20 038 mm 0 7889 in Bearing Surface O D New 19 962 19 975 mm 0 7859 0 7864 in Max Wear Limit 19 959 mm 0 7858 in Connecting Rod Connecting Rod to Crankpin Running Clearance New 0 030 0 055 mm 0 0012 0 0022 in Max Wear Limit 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 17 015 17 023 mm 0 6699 0 6702 in Max Wear Limit 17 036 mm 0 6707 in Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 8 KohlerEngines com 24 690 30 Rev D Specifications CLEARANCE SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 CH730 CH740 Crankcase Governor Cross Shaft Bore I D 6 mm Shaft New 6 025 6 050 mm 0 2372 0 2382 in Max Wear Limit 6 063 mm 0 2387 in 8 mm Shaft New 8 025 8 075 mm 0 3159 0 3179 in Max Wear Limit 8 088 mm 0 3184 in Crankshaft End Play free 0 070 0 590 mm 0 0028 0 0230 in End Play w thrust bearing components 0 070 1 190 mm 0 0028 0 0468 in Except CH25 Engines Below Serial No 2403500008 0 050 0 750 mm 0 0020 0 0295 in Bore in crankcase New 40 965 41 003 mm 1 6128 1 6143 in Max Wear Limit 41 016 mm 1 6148 in Crankshaft to Sl
9. 25 455 12 S reamer DTI K830 AIDS Description Source Part No RTV Silicone Sealant Loctite 5900 Heavy Body in 4 oz aerosol dispenser Kohler 25 597 07 S Only oxime based oil resistant RTV sealants such as those listed are approved Loctite 59109 for use Loctite Nos 5900 or 5910 are recommended for best sealing Loctite Ultra Black 598 characteristics Loctite Ultra Blue 587 Loctite Ultra Copper 5920 Spline Drive Lubricant Kohler 25 357 12 S 14 KohlerEngines com 24 690 30 Rev D FLYWHEEL HOLDING TOOL A flywheel holding tool can be made out of an old junk flywheel ring gear and used in place of a strap wrench 1 Using an abrasive cut off wheel cut out a six tooth segment of ring gear as shown 2 Grind off any burrs or sharp edges 3 Invert segment and place it between ignition bosses on crankcase so tool teeth engage flywheel ring gear teeth Bosses will lock tool and flywheel in position for loosening tightening or removing with a puller 24 690 30 Rev D Tools and Aids ROCKER ARM CRANKSHAFT TOOL p A spanner wrench to lift rocker arms or turn crankshaft may be made out of an old junk connecting rod 1 Find a used connecting rod from a 10 HP or larger engine Remove and discard rod cap 2 Remove studs of a Posi Lock rod or grind off aligning steps of a Command rod so joint surface is flat 3 Finda 1 in long capscrew with correct thread size to match threads in conne
10. 30 Rev D Reassembly Install Closure Plate Assembly Sealant Pattern and Torque Sequence RTV sealant is used as a gasket between closure plate and crankcase Always use fresh sealant Using outdated sealant can result in leakage Be sure sealing surfaces have been cleaned and prepared Install a new O ring in closure plate Check to make sure there are no nicks or burrs on sealing surfaces of closure plate or crankcase Apply a 1 5 mm 1 16 in bead of sealant to sealing surface of closure plate Make sure end of governor cross shaft is lying against bottom of cylinder 1 inside crankcase Install closure plate to crankcase Carefully seat camshaft and crankshaft into their mating bearings Rotate crankshaft slightly to help engage oil pump and governor gear meshes Install screws securing closure plate to crankcase Torque fasteners to 24 4 N m 216 in Ib following sequence On some engines one mounting screw is plated Plated screw is typically installed in hole location 6 For LPG engines install vaporizer bracket to hole locations 8 and 10 KohlerEngines com 15 Reassembly Flywheel Ignition Components Debris Screen B Fa C Fiyheeiserew D Flywheel F Magnet G star H ignition Module Backing Plate Woodruff Key K Spring Washer Metal Debris Screen Ring Support rm Metal Debris Screen o Wee P Assembly Install Stator and Backing Plates NOTE Make sure flywheel key is instal
11. ASSEMBLY Electric Lock off Filter Components a Weng B Filter Outlet Fitting Functional Test Electric lock off can be easily tested to verify that it is functional Remove it from system for testing Using a 12 volt power supply or battery connect one wire lead to positive lead of power supply and touch remaining wire lead to negative lead of power supply When connection is made an audible click should be heard indicating opening of lock off While energized blow compressed air through it to determine if it is blocked or restricted Filter Service Filter inside lock off assembly should be replaced Cleaning of filter element is not recommended Order a replacement filter element by appropriate Kohler part number 24 690 30 Rev D Fuel System VAPORIZER ASSEMBLY IMPCO Beam Regulator Vaporizer Components Details and Components U A Veponzer B Fiting Outer surface of vaporizer should be kept free of dirt and debris accumulation which will cause a loss of S Kaze S vaporization efficiency Visual inspection and necessary N 7907 SIR cleaning should be performed on a regular basis more DIT 7 CT eM MEZ ZZ MM MM NNN frequently under dusty or dirty conditions LPG NG REGULATOR Regulator controls both pressure and flow of fuel within A Expansion Plug LPG NG system It is comprised of both a primary and Expansion Plug _ secondary chamber which are dependent upon one C
12. Oil Seal Make sure all traces of any cleaner are removed before 1 Make sure seal bore of crankcase is clean and free engine is assembled and placed into operation Even of any nicks or burrs small amounts of these cleaners can quickly break down 2 lubricating properties of engine oil Apply a light coat of clean 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 72 KohlerEngines com 24 690 30 Rev D Install Governor Cross Shaft 1 2 Lubricate governor cross shaft bearing surfaces in crankcase with engine oil Slide small lower washer onto governor cross shaft and install cross shaft from inside of crankcase 6 mm governor shaft Install plain washer and then insert hitch pin into smaller lower hole of governor cross shaft 8 mm governor shaft 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 Install Connecting Rods with Pistons and Rings Piston and Connecting Rod Details Cylinder B Cylinder 2 Connecting Rod Bolt Details
13. 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 test ignition modules and white kill lead connection for affected DSAI module DSAI only 42 KohlerEngines com 24 690 30 Rev D 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 connected 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
14. 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 Cuta 50 75 mm 2 3 in piece from end of an old push rod and chuck it in a drill press 2 Layaragor 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 30 Rev D Flywheel Ignition Components Remove Ignition Modules 1 Disconnect lead s from each ignition module Modules for non SMART SPARK ignition systems have only one kill lead 2 Rotate flywheel so magnet is away from modules 3 Remove mounting screws and ignition modules Note position of ignition modules Remove Debris Screen and Fan 1 Small metal retainers are typically attached on 3 of 7 mounting posts for positive retention of plastic debris screen Use a hook end tool next to post and pull outwar
15. against 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 Starter System 10 Starter reassembly when replacing brushes brush 11 12 19 14 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 ser
16. air and rises Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area To ensure personal safety installation and repair of LPG NG fuel supply systems must be performed only by qualified LPG NG system technicians Improperly installed and maintained LPG NG equipment could cause fuel supply system or other components to malfunction causing gas leaks Observe federal state and local laws governing LPG NG fuel storage and systems Rotating Parts can cause Stay away while engine is in operation Keep hands feet hair and clothing away from all moving parts to prevent injury Never operate engine with covers shrouds or guards removed 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 Accidental Starts can cause severe injury or death Disconnect and ground spark plug lead s before servicing Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect negative battery cable from battery Before disconnecting negative ground cable make sure all switches are OFF If ON a spark will occur at ground cable terminal which could cause an explosion if hydrogen gas or LPG NG fuel vapor
17. and rear stop collars together over retainer Using two pairs of pliers apply even force to two collars until they snap over retainer and nest into one another Reassemble remaining components of starter in reverse order from disassembly Delco Remy Starters Starter Disassembly NOTE Do not reuse old retainer NOTE Do not soak armature or use solvent when 1 cleaning Wipe clean using a soft cloth or use compressed air Remove hex nut and disconnect positive brush lead bracket from solenoid terminal KohlerEngines com 53 Starter System 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 o 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
18. 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 An 0 25 mm 0 010 in undersized rod can be identified by a drilled hole located in 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 Details Self Tapping Screw B Flat Washer C Pug DI Crankshaft amp Fillet Must Blend Smoothly with Bearing Journal Surface Fr High Point from Fillet Intersections G 45 Minimum H This Fillet Area Must Be Completely Smooth NOTE If crankpin is reground visually check to ensure fillet blends smoothly with crankpin surface NOTE To prevent repeat failures camshaft and crankshaft should always be replaced as a set 24 690 30 Rev D Disassembly Inspection and Service Carefully pull crankshaft from crankcase Note thrust washers and shims if used Inspect gear teeth of crankshaft If teeth are badly worn chipped or some are missing replacement of crankshaft will be necessary Inspect crankshaft bearing surfaces for scoring grooving etc Some engines have bearing inserts in crankshaft bore of closure plate and or crankcase Do not replace bearings unless they show signs of damage
19. clogged or leaking Intake system leak Loose wires or connections that intermittently ground ignition kill circuit e Quality of fuel dirt water stale mixture e Restricted fuel tank cap vent Engine Starts Hard e Clogged fuel line or fuel filter e Engine overheated e Faulty ACR mechanism e Faulty or misadjusted choke or throttle controls e Faulty spark plug s e Flywheel key sheared e Fuel pump malfunction vacuum hose clogged or leaking Interlock switch is engaged or faulty e Loose wires or connections that intermittently ground ignition kill circuit e Low compression e Quality of fuel dirt water stale mixture e Weak spark 16 KohlerEngines com Engine Will Not Crank Battery is discharged Faulty electric starter or solenoid Faulty key switch or ignition switch Interlock switch is engaged or faulty Loose wires or connections that intermittently ground ignition kill circuit Pawls not engaging in drive cup Seized internal engine components Engine Runs But Misses Carburetor adjusted incorrectly Engine overheated Faulty spark plug s Ignition module s faulty or improperly gapped Incorrect crankshaft position sensor air gap Interlock switch is engaged or faulty Loose wires or connections that intermittently ground ignition kill circuit Quality of fuel dirt water stale mixture Spark plug lead s disconnected Spark plug lead boot loose on plug Spark plu
20. collar over inner halves to hold them in position 5 Thread center screw into removal tool until you feel resistance Use a wrench 1 1 8 or adjustable to hold base of removal tool Use another wrench or socket 1 2 in or 13 mm to turn center screw clockwise Resistance against center screw will tell you when retaining ring has popped out of groove in armature shaft 6 Remove drive components from armature shaft paying attention to sequence If splines are dirty clean them with solvent 7 Splines should have a light film of lubricant Relubricate as necessary with Kohler starter drive lubricant Reinstall or replace drive components assembling them in reverse order they were removed KohlerEngines com 51 Starter System Retaining Ring Installation 1 Position retaining ring in groove in one of inner halves Assemble other half over top and slide on outer collar 2 Be certain drive components are installed in correct sequence onto armature shaft 3 Slip tool over end of armature shaft so retaining ring inside is resting on end of shaft Hold tool with one hand exerting slight pressure toward starter Tap top of tool with a hammer until you feel retaining ring snap into groove Disassemble and remove tool 4 Squeeze retaining ring with a pliers to compress it into groove o Assemble inner halves with larger cavity around spring retainer Slide collar over them and thread center screw in until resistance is f
21. 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 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 70 KohlerEngines com 24 690 30 Rev D 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
22. leaking fuel enrichment hose IMPCO carburetor system Irregular or inconsistent idle Improper operation adjustment of regulator idle adjustment screw throttle opening and or engine governor Secondary valve in regulator not closing Readjust idle screw counterclockwise so valve can close fully against seat disassemble body and remove debris Dirt or debris in carburetor Remove carburetor disassemble and clean service as required If venturi IMPCO carburetor removal is performed mark its orientation Excessive external load on engine to carburetor body for proper reinstallation Loose leaking fuel enrichment hose IMPCO carburetor system 24 690 30 Rev D KohlerEngines com 23 Fuel System Rich gas condition flooding through regulator e Dirty restricted valves in regulator e Damaged primary diaphragm in regulator No fuel Electric lock off not opening filter blocked or restriction within fuel line Leaking loose or cracked vacuum line from carburetor to regulator Leaking or loose intake system components Secondary or vacuum lock off diaphragm within regulator leaking Low pressure rubber hose kinked Frozen regulator Improper ignition timing Loose incorrect throttle lever clamp bracket positioning e e o e Regulator primary valve not opening o e Loose or incorrectly positioned high speed throttle plate stop Engine runs lean Electrical problem causing intermittent lock off
23. localized hot spots resulting from blocked cooling fins or 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 one of these oversizes will allow usage of available oversize piston and ring assemblies First resize using a boring bar then follow these procedures for honing cylinder Honing Detail 23 33 Crosshatch NOTE Some CH25 engines feature POWER BORE cylinders a special patented nickel silicone plating process for increased power superior oil control reduced exhaust emission and virtually permanent cylinder life POWER BORE cylinders cannot be resized or honed as described in these procedures If a plated cylinder bore is damaged or out of specification use a new miniblock or short block to repair engine Use following procedure for crankcases with a cast iron sleeve 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
24. lock off filter from vaporizer Remove screws securing vaporizer and bracket Remove Control Panel if equipped 1 Disconnect Oil Sentry indicator light wires 2 Disconnect choke control cable from control bracket 3 Disconnect throttle control cable or shaft 4 Remove panel from blower housing 24 690 30 Rev D Remove Throttle and Choke Controls C Spring D Govemor Lever re Nut F Throttle Linkage 1 Remove screws securing control bracket and rear air cleaner bracket Some models to cylinder heads 2 Mark spring hole locations and disconnect spring from governor lever 3 Remove choke linkage from choke actuator lever and carburetor Remove External Governor Controls Loosen nut and remove governor lever from cross shaft Leave lever attached to throttle linkage and lay assembly on top of crankcase 24 690 30 Rev D Disassembly Inspection and Service Remove Carburetor Explosive Fuel can cause fires and severe burns If a gaseous odor is detected ventilate area and contact an authorized service technician LPG is extremely flammable and is heavier than air and tends to settle in low areas where a spark or flame could ignite gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area NG is extremely flammable is lighter than air and rises Do not start or operate this engine in a poorly ventilated ar
25. not excessively 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 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 E 24 690 30 Rev D 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
26. open before reassembling Do not use wire or metal objects to clean passages or carburetor body Fuel System LPG NG Carburetor Inspection NOTE Do not attempt to disassemble or remove either shaft from carburetor body including mounted clamp brackets on IMPCO style carburetors Screws attaching choke and throttle plate to their respective shafts are staked or bonded to prevent loosening Plate s and shaft s are not available separately If detrimental wear or damage is found in any parts carburetor should be replaced 1 Inspect carburetor body and removable venturi IMPCO carburetor for cracks holes and other wear or damage 2 Check choke shaft Nikki carburetor only and throttle shaft for wear and free movement LPG NG Carburetor Reassembly IMPCO Carburetor NOTE Clamp brackets and stop collar mounted on throttle shaft should still be in their original positions and not require any readjustment resetting If mounted position of any one of these was affected or changed it will be necessary to check and reset position of each before proceeding Follow Instructions for Checking Positioning Clamp Brackets Mounted on Throttle Shaft then continue with steps 6 and 7 1 Slide venturi into carburetor body aligning position mark made prior to removal Correctly installed discharge holes should not be visible from top 2 Secure with venturi retaining screw Torque screw to 4 0 N m 36 in Ib 3 Install a
27. 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 30 Rev D Typical LPG NG fuel systems and related components include Fuel Tank Liquid Withdrawal LPG only Electric Lock Off Filter Assembly Vaporizer LPG only Regulator Combination Primary Secondary Vacuum Lock Off e Carburetor e High Pressure Fuel Line s LPG only e Vacuum Line LPG NG fuel travels through fuel line to electric lock off filter assembly Lock off opens internally when key switch is turned ON permitting filtered fuel to flow A vaporizer LPG only is mounted in flow of discharged cooling air It absorbs heat from cooling air and transfers it to fuel changing liquefied petroleum to a vapor or gaseous state while partially stepping down fuel pressure Gas vapor flows under this decreased pressure to regulator where it is further reduced to a usable regulated pressure Regulator activated by intake manifold vacuum controls fuel flow to carburetor In venturi of carburetor fuel vapor is mixed with incoming air from air cleaner in correct ratio for efficient combustion External Fuel System Components P nr ug i rA Er m oki i a ee ye LL T
28. operation or lock off is faulty Filter in lock off dirty or restricted Restriction in fuel system Idle holes plugged dirt in fuel delivery channels Loose leaking fuel enrichment hose IMPCO carburetor system High fuel consumption Fuel leak Check lines connections and system components for leaks with soapy water Fix any leaks immediately Incorrectly set regulator or leakage from valves in regulator Readjust service or replace regulator as required Dirty air cleaner or precleaner Choke plate in carburetor not opening completely Carburetor fuel circuit restriction LPG NG CARBURETOR ADJUSTMENTS Some IMPCO carburetors incorporate an external NOTE Carburetor adjustments should be made only load block assembly which controls final fuel flow to after engine has warmed up carburetor for all throttle positions except idle Calibrated NOTE Actual low idle speed RPM depends on and flow matched to carburetor it functions similarly to preset fuel mixture settings in other carburetors Load recommendations Low idle speed for basic block assembly is not available separately nor is any engines is 1200 RPM internal servicing permitted or possible If a problem is l encountered and determined to be caused by load block LPG NG carburetor and regulator are designed to deliver carburetor should be replaced correct fuel to air mixture to engine under all operating conditions High and low idle fuel mixture settings are LPG NG
29. overtighten 24 690 30 Rev D KohlerEngines com 55 Starter System 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 To test solenoid hold in coil Actuation Function 1 Use a 12 volt power supply and 2 test leads 1 Connecta 12 volt test lead to flat spade S start 2 Connect 1 lead to flat spade S start terminal on Eas on er in a lead to body or solenoid Momentarily connect other lead to lower mounting surface or Solenold large post terminal 2 Manually push plunger IN and check if coil holds When connection is made solenoid should energize plunger retracted Do not allow test leads to remain audible click and plunger retract Repeat test connected to solenoid for a prolonged period of time several times Continuity Continuity 1 Use an ohmmeter set to audible or Rx2K scale and 1 Use an ohmmeter set to audible or Rx2K scale and connect 2 ohmmeter leads to 2 large post terminals connect 2 ohmmeter leads to 2 large post terminals 2 Perform preceding solenoid hold in coil function test and check for continuity Meter should indicate 2 Perform solenoid pull in coil plunger actua
30. position brushes in their pockets in carrier Move them to retracted position and install carton staples to retain them Align terminal stud block with notch in starter frame and slide brush carrier assembly into frame Commutator will push carton staples out as brush assembly is installed Position end cap over brush assembly so holes for thru bolts are aligned with those in brush carrier o Install thru bolts and tighten securely 6 Lubricate drive shaft with Kohler starter drive lubricant Install drive components following instructions for servicing starter drive 24 690 30 Rev D SOLENOID SHIFT ELECTRIC STARTERS Solenoid Shift Starter Components A Brush Holder U X Bot 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 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 24 690 30 Rev D B Weser D Die E F Retaining Ring G Colar H DrveEndCap EE J Plngr K Sing EL Lever M N Pug O Solenoid P FrameandField a R Nt Commutator End s omgee r so NN Starter System Nippondenso Starters Starter Disassembly NOTE When removing lever and a
31. spring tension moves them inward as speed decreases e As flyweights move outward they cause regulating pin to move outward e 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 e 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 30 KohlerEngines com Throttle Lever Adapter o DLA Bracket I Linkage Spring Governor Control Unit GCU e 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 tamper 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 Adjus
32. 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 NOTE Do not completely tighten screws until all items are installed to allow shifting for hole alignment 1 Connect plug to key switch in blower housing if equipped 2 Slide blower housing into position over front edge of inner baffles Start a few screws to hold it in place Make sure ground lead and oil pressure switch leads are accessible and in proper position 24 690 30 Rev D Reassembly 3 Position outer baffles and loosely start mounting screws M6 screws go into back of cylinders Short M5 screws go into lower holes closest to blower housing Short screw on oil filter side is also used to mount wire harness clip Be sure any wire harnesses or leads are routed out through proper offsets or notches so they will not be pinched between blower housing and baffles 4 Ifrectifier regulator was not removed attach ground wire or metal grounding bracket for rectifier regulator using silver colored screw and washer to lower blower housing hole 5 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 Torque shorter M5 side baffle screws to 4 0 N m 35 in Ib Torque upper 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
33. tool and replace shim as necessary Several color coded shims are available White 0 69215 0 73025 mm 0 02725 0 02875 in Blue 0 74295 0 78105 mm 0 02925 0 03075 in Red 0 79375 0 83185 mm 0 03125 0 03275 in Yellow 0 84455 0 88265 mm 0 03325 0 03475 in Green 0 89535 0 99345 mm 0 03525 0 03675 in Gray 0 94615 0 98425 mm 0 03725 0 03875 in Black 0 99695 1 03505 mm 0 03925 0 04075 in 5 Reinstall end play checking tool and recheck end play Oil Pump Assembly Oil pump is mounted inside closure plate If service was required and oil pump was removed refer to Disassembly Inspection and Service p ORL A Governor Gear Assembly Governor gear assembly is located inside closure plate If service was required and governor was removed refer to Disassembly Inspection and Service 74 KohlerEngines com Thrust Bearing Washer and Shim Thrust Bearing Washer and Shim Sequence Thrust Washer Needle Thrust E INDIEN Closure Plate Some specifications use a needle type thrust bearing thrust washer and shim spacer to control end play of crankshaft If these items are noted during disassembly make sure they are reinstalled in sequence shown A different procedure will have to be followed to check and adjust crankshaft end play on these models Race for thrust bearing presses loosely into closure plate If it is not already installed push it into crankshaft bore inside closure plate Pack thrus
34. 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 All ignition systems are designed to be trouble free for life of engine Other than periodically checking replacing spark plugs no maintenance or timing adjustments are necessary or possible Mechanical systems do occasionally fail or break down Refer to Troubleshooting to determine root of a reported problem Reported ignition problems are most often due to poor connections Before beginning test procedure check all external wiring Be certain all ignition related wires are connected including spark plug leads Be certain all terminal connections fit snugly Make sure ignition switch is in run position KohlerEngines com 35 Electrical System Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with Fixed Timing 36 KohlerEngines com 24 690 30 Rev D Electrical System Fixed Ignition System This system uses a capacitive discharge CD coil Ignition timing and spark remains constant regardless of engine speed Timing of spark is controlled by location of flywheel magnet group as referenced to engine TDC A typical fixed ignition system consists of e 1 magnet assembly which is permanently affixed to flywheel e 2 electronic capacitive discharge ignition modules which mount on engine crankcase e 1 kill switch or key swit
35. 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 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 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
36. 12 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 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 0 280 0 330 mm 0 011 0 013 in Reassembly Install Intake Manifold Torque Sequence NOTE If wires were disconnected from ignition modules on engines with SMART SPARK reattach leads and seal base of terminal connectors with GE Novaguard G661 or equivalent dielectric compound Beads should overlap between terminals to form a solid bridge of compound Do not put any compound inside terminals 24 584 15 S ignition modules have a separator barrier between terminals On these modules seal base of terminals but it is not necessary to have overlapping beads of sealant between connections Install intake manifold and new gaskets or O rings plastic manifold with wiring 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 Connect kill lead to tab terminal on standard ignition mo
37. 35 in Ib in a used hole Torque two rear 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 6 Ifan overlapping style flywheel screen is used attach it to supports or flywheel For a metal flywheel screen apply Loctite 242 to screw threads M6 and torque to 9 9 N m 88 in Ib Torque plastic screen mounting screws M4 to 2 2 N m 20 in Ib 7 Torque breather cover screws to 7 3 N m 65 in Ib in sequence shown Reconnect Rectifier Regulator 1 Install rectifier regulator in blower housing if removed previously then connect rectifier regulator ground lead with washer and silver screw through eyelet If a grounding bracket is used secure with lower 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 SMART SPARK Module On engines with SMART SPARK reinstall SAM Module to blower housing or cylinder baffle Do not overtighten retaining screws Install Electric Starter Motor NOTE If engine uses a side mount muffler on starter side be sure to tie wires close to starter to avoid contact with hot exhaust parts 1 Install starter motor using two screws Some inertia drive starters have a pinion cover and spacers on starter bolts 2 Torque screws to 15 3 N m 135 in Ib 3 On models with a solenoid shift sta
38. 5 01 S Cylinder Leakdown Tester Kohler 25 761 05 S Oil Pressure Test Kit Kohler 25 761 06 S Rectifier Regulator Tester 120 V AC 60Hz Kohler 25 761 20 S Dealer Tool Kit International Kohler 25 761 42 S Complete kit of Kohler required tools Components of 25 761 42 S Ignition System Tester Kohler 25 455 01 S Cylinder Leakdown Tester Kohler 25 761 05 S Oil Pressure Test Kit Kohler 25 761 06 S Rectifier Regulator Tester 240 V AC 50Hz Kohler 25 761 41 S Digital Vacuum Pressure Tester Design Technology Inc For checking crankcase vacuum DTI 721 01 Individual component available Design Technology Inc Rubber Adapter Plug DTI 721 10 Electronic Fuel Injection EFI Diagnostic Software Kohler 25 761 23 S For Laptop or Desktop PC EFI Service Kit Kohler 24 761 01 S For troubleshooting and setting up an EFI engine Components of 24 761 01 S Design Technology Inc Fuel Pressure Tester DTI 019 Noid Light DTI 021 90 Adapter DTI 023 In line T Fitting DTI 035 Code Plug Red Wire DTI 027 Code Plug Blue Wire DTI 029 Shrader Valve Adapter Hose DTI 037 Flywheel Puller SE Tools KLR 82408 For properly removing flywheel from engine 24 690 30 Rev D KohlerEngines com 13 Tools and Aids TOOLS Description Source Part No Hydraulic Valve Lifter Tool Kohler 25 761 38 S For removing and installing hydraulic lifters Ignition System Tester Kohler 25 455 01 S For testing output on all systems including CD Inductive Tachomete
39. 56 58 17 976 18 HP MECHANICAL FUEL PUMP 11 888 5 8 18 UNF 2B 38 10 1 500 DEEP 20 28 HP a 7 16 20 UNF 28 00 38 10 1 500 DEEP 55 7 16 14 UNC 2B INCH 18 HP 15 21 00 0 827 DEEP 196 85 7 750 B C PILOT 177 80 7 000 24 690 30 Rev D KohlerEngines com MOUNT ING SURF ACE MOUNTING HOLE A Specifications ENGINE IDENTIFICATION NUMBERS Kohler engine identification numbers model specification and serial should be referenced for efficient repair ordering correct parts and engine replacement Command Engine Horizontal Shaft Numerical Designation Specification CH640 0001 SII MF 4323500328 Year Manufactured Code TT L Factory Code Year 2013 2014 2015 GENERAL SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 Dp m 3 03 in 3 T in Stroke 38 cu in cu in 44 cu in Maximum Angl i Operation full oil level ti TORQUE SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 CH730 CH740 Blower Housing and Sheet Metal M5 Fasteners 6 2 N m 55 in Ib into new holes 4 0 N m G5 in Ib into used holes M6 Fasteners 10 7 N m 95 in X into new holes T 3 Nem 65 1 in Ib u used holes Carburetor and Intake Manifold Intake Manifold Mounting Fastener torque in 2 first to 7 4 N m 66 in Ib increments finally to 9 9 N m 88 in Ib M6 Mounting Screw or Nut 6 2 7 3 N m 55 65 in Ib Closure Plate 24 4 N m 216 in Ib Conn
40. Check to be sure all system connections are tight 7 Resetidle RPM and recheck high idle governed speed after starting and allowing sufficient warm up time Instructions for Checking Positioning Clamp Brackets Mounted on Throttle Shaft Use only if position or mounting of clamp bracket s has been disturbed Idle Speed Clamp Bracket Position 1 Counting number of turns back idle speed adjustment screw off counterclockwise so only 1 to 1 1 2 threads are visible 2 Loosen clamp bracket mounting screw and pivot throttle shaft to fully close throttle plate 3 Hold throttle plate closed and rotate clamp bracket until end of screw contacts stop Insert a 0 025 mm 0 001 in feeler gauge between carburetor housing and side of clamp bracket to set endplay then tighten mounting screw securely 4 Resetidle speed adjustment screw back to original position High Speed Stop Collar Position NOTE After idle speed clamp bracket and high speed stop collar positions have been set check that throttle shaft pivots freely without binding or restriction 1 Make sure idle speed clamp position has already been checked or properly set 2 Rotate and hold throttle shaft so throttle plate is fully open perfectly vertical 3 Insert a 0 025 mm 0 001 in feeler gauge between side of stop collar and carburetor housing then check or set position of stop collar Head of mounting screw must be in contact with carburetor boss from b
41. E Novaguard G661 or equivalent dielectric compound Beads should overlap between two connections to form a solid bridge of compound Do not put any compound inside connectors 24 584 15 S ignition modules have a separator barrier between terminals On these modules seal base of terminal if any portion of it is exposed but it is not necessary to have overlapping beads of sealant between connections 5 Test for spark to be sure system is working before you reinstall blower housing If there is still a spark problem on one side replace that ignition module and recheck spark Test ASAM and DSAM Allow 15 20 seconds for tester to clear and reset itself between tests or if test is interrupted before completion of test cycle Otherwise a false reading may be displayed in form of a or a faint 8 Tester is powered by a 9 volt battery Most SAMs are designed to operate down to a minimum of 7 25 volts If tester battery drops below that level incorrect test readings will result Tester battery should be checked periodically by connecting a DC voltmeter between red and green lead wires with tester connected to a SAM Press and hold test button for a full test cycle F or P appears and then display shuts off while monitoring voltage reading on voltmeter If voltage drops below 7 5 at any time during cycle 9 volt tester battery must be replaced Use an extended life alkaline battery To replace battery remove outer set of screws on faceplate a
42. FUEL SYSTEM COMPONENT SERVICE preset at factory and cannot be adjusted These engines LPG NG Carburetor Cleaning are equipped with an IMPCO or Nikki carburetor Although both carburetors function similarly each is unique and should not be interchanged application Refer to equipment manufacturer s Carburetor may be cleaned if necessary Removal from engine and limited disassembly will aid in cleaning 24 KohlerEngines com 24 690 30 Rev D IMPCO Carburetor NOTE Do not loosen or alter mounted position of clamping brackets and or stop collar on throttle shaft Each is preset in correlation to a specific position of throttle plate shaft or acts as a stop None of these attached components including throttle plate or shaft requires disassembly or removal for any carburetor servicing All components on throttle shaft should be left intact If settings of any one of these is inadvertently loosened or altered each must be checked reset or performance and operation will be affected Refer to procedure included in reassembly installation sequence to check or reset Turn off fuel supply at tank Remove air cleaner breather hose fuel line vacuum hose choke and throttle linkages Remove mounting hardware carburetor and gaskets from engine Discard gaskets Carburetor venturi may be removed for inspection and appropriate cleaning a Remove screws securing air cleaner adapter and gasket to carburetor b Mark a sma
43. Ib Testing Compressed air a pressure regulator pressure gauge and a continuity tester are required to test switch 1 Connect continuity tester across blade terminal and metal case of switch With O psi pressure applied to switch tester should indicate continuity switch closed 2 Gradually increase pressure to switch As pressure increases through range of 3 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 3 5 psi Tester should indicate a change to continuity switch closed down to O psi 4 Replace switch if it does not operate as specified 24 690 30 Rev D KohlerEngines com Lubrication System 33 Electrical System SPARK PLUGS A CAUTION p Electrical Shock can cause injury Gy Do not touch wires while engine is running Spark Plug Component and Details A WireGauge B SparkPlug 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 a is equipped with following spark plugs 0 76 mm 0 03 in all except NG CD Fixed 0 51 mm 0 02 in NG CD Fixed Thread Size 14 mm 19 1 mm 3 4 in 15 9 mm 5 8 i
44. Inspect wiring for any damage cuts bad crimps loose terminals or broken wires Check that connections are oriented properly on terminals of modules 2 Disconnect leads from ignition module s and clean all of terminals male and female with aerosol electrical contact cleaner to remove any old dielectric compound dark residue dirt or contamination Disconnect spark plug leads from spark plugs 3 Using a multi meter check that a proper ground is established between ground black lead of DSAI module closest to spark plug lead and a known good ground location on engine 4 Turn key switch to ON position and check for 12 volts at center power red lead terminal of DSAI module Use same ground location for multi meter as in checking for timing advance Condition Possible Cause Conclusion All tests are OK but module has no Ignition Module Replace affected module spark or fails to advance Any test is BAD Ignition Module or Connections Determine cause and fix as required retest 24 690 30 Rev D KohlerEngines com 43 Electrical System Test Ignition Modules and Connections Smart Spark only NOTE Resistance values apply only to modules that have been on a running engine New service modules may have higher resistance until they have been run 1 Remove blower housing from engine Inspect wiring for any damage cuts bad crimps loose terminals or broken wires 2 Disconnect leads from ignition module s and clea
45. KOHLER Command CH18 CH20 CH23 CH25 CH640 CH730 CH740 Liquefied Petroleum Gas LPG or LPG Natural Gas NG Fueled Service Manual IMPORTANT Read all safety precautions and instructions carefully before operating equipment Refer to operating instruction of equipment that this engine powers Ensure engine is stopped and level before performing any maintenance or service 2 Safety 3 Maintenance 5 Specifications 13 Tools and Aids 16 Troubleshooting 20 Air Cleaner Intake 21 Fuel System 30 Governor System 32 Lubrication System 34 Electrical System 50 X Starter System 57 Disassembly Inspection and Service 2 Reassembly 24 690 30 Rev D 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 Explosive Fuel can cause fires and severe burns If a gaseous odor is detected ventilate area and contact an authorized service technician LPG is extremely flammable and is heavier than air and tends to settle in low areas where a spark or flame could ignite gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area NG is extremely flammable is lighter than
46. Nikki Carburetor Components A Venti B eme Idle Speed Adjustment Screw ry Throttle Lever OR G Venturi Retaining Load Block E Screw if equipped Rear Plug with Idle Speed Clamp Sealing Washer B Fuel Inlet Bracket Mounting m ne Choke Lever Screw if equipped Assembly o Throttle Lever i Idle Speed a PASM RUANG I Adjustment Screw Transfer Chamber e vacuum ron n MES Choke Plate Shaft Assembly 22 KohlerEngines com 24 690 30 Rev D Fuel System TROUBLESHOOTING CHECKLIST 4 Make sure ignition governor exhaust throttle and If engine starts hard runs roughly or stalls check choke control systems are all operating properly following areas 5 Check compression 1 Make sure LPG fuel tank is filled and shut off valve If engine continues to start hard run roughly or stall is fully opened after these checks have been made use following 2 Make sure fuel is reaching carburetor troubleshooting guide 3 Make sure air cleaner element and precleaner are clean and all components are fastened securely Insufficient vacuum signal regulator not opening e Vacuum line between carburetor and regulator cracked leaking kinked or pinched e Carburetor loose e Intake manifold loose or leaking e Excessive internal engine wear Faulty regulator e Primary valve not opening e Diaphragm spring adjustment incorrect e Idle adjustment screw incorrectly set e Vent s blocked restricted Loose
47. 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 Remove Governor Cross Shaft 1 Remove hitch pin and plain washer or retainer and nylon washer from governor cross shaft 2 Pull cross shaft with small washer out through inside of crankcase KohlerEngines com 69 Disassembly Inspection and Service Governor Cross Shaft Oil Seal Cross Shaft Oil Seal Details 2 0 mm 0 0787 in 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 seal installer Remove Flywheel End Oil Seal Remowve 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 Inspect main bearing if equipped for wear or damage Replace crankcase using a miniblock or short block as required Check cylinder bore wall 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
48. ack hose fitting side preventing any further rotation over center Set or adjust stop collar as required 4 Tighten screw securely Throttle Linkage Clamp Bracket Position Carburetor must be assembled to engine with linkage attached to set this position 1 Throttle linkage clamp bracket should be positioned on idle speed clamp bracket side of throttle shaft 26 KohlerEngines com 2 Manually move governor lever with throttle linkage connected toward carburetor as far as it will go Hold it in this position 3 Looking down throat of carburetor check that throttle plate is in full throttle position and that head of high speed oollar stop screw is in contact with carburetor boss If not loosen carburetor mounting hardware and reposition carburetor slightly Torque carburetor mounting screws or nuts to 6 2 7 3 N m 55 65 in Ib HIGH ALTITUDE OPERATION Standard carburetor calibrations will provide proper operation up to altitudes of 1500 m 5000 ft No internal changes are necessary or available for either carburetor Idle Speed Adjustment 1 Start engine and run at half throttle for 5 to 10 minutes Check that throttle and choke Nikki carburetor plates can open fully 2 Place throttle control into idle or slow position Turn low idle speed adjusting screw in or out to obtain a low idle speed of 1200 RPM x 75 RPM or set to application specifications Check speed using a tachometer ELECTRIC LOCK OFF FILTER
49. air cleaner bracket is used install two M5 screws through rear of base Torque three M6 screws to 6 2 7 3 N m 55 65 in Ib and two rear M5 mounting screws when applicable to 4 0 N m 35 in Ib 4 Install breather hose in hole of bracket 5 Install air cleaner components refer to Air Cleaner Intake Install 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 nuts to exhaust studs Torque nuts to 24 4 N m 216 in Ib Install Oil Cooler if equipped Oil cooler can now be installed to engine Two different styles are used 1 Depending on style used reverse removal procedure from Disassembly 2 Secure cooler or adapter to oil pan with oil filter nipple Torque oil filter nipple to 27 N m 20 ft Ib 24 690 30 Rev D Install Oil Filter and Fill Crankcase with Oil NOTE Make sure 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 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 Referto instructions on oil filter for proper installat
50. ake AIR CLEANER These systems are CARB EPA certified and components should not be altered or modified in any way Air Cleaner Components lt U Z SS Air Cleaner Cover B Air Cleaner Knob Wing Nut D Element Cover E Rubber Seal Precleaner G Paper Element H Air Cleaner Base NOTE Operating engine with loose or damaged air cleaner components could cause premature wear and failure Replace all bent or damaged components NOTE Paper element cannot be blown out with compressed air Loosen knob and remove air cleaner cover Precleaner Remove precleaner from paper element 2 Replace or wash precleaner in warm water with detergent Rinse and allow to air dry 3 Saturate precleaner with new engine oil squeeze out excess oil 4 Reinstall precleaner over paper element Paper Element 1 Clean area around element Remove wing nut element cover and paper element with precleaner 2 Separate precleaner from element service precleaner and replace paper element 3 Check condition of rubber seal and replace if necessary 4 Install new paper element on base install precleaner over paper element reinstall element cover and secure with wing nut Reinstall air cleaner cover and secure with knob 20 KohlerEngines com BREATHER TUBE Ensure sure both ends of breather tube are properly connected AIR COOLING 2 9 Hot Parts can cause severe burns Aiit Do not touch engine while
51. and drain any accumulated deposits 4 Reinstall plug using pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent on threads and tighten securely If required a replacement plug can be found at KohlerEngine com Regulator Service It is recommended that disassembly cleaning and resetting of regulator be performed using regulator rebuilding kit available at KohlerEngine com Specific instructions are included in rebuilding kit Perform regulator service following instructions provided As all adjustments and settings must be reset using specific test equipment this must be performed by qualified LPG NG personnel only 24 690 30 Rev D KohlerEngines com Fuel System 29 Governor System 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 closure plate and is driven off gear on camshaft Governor Components Throttle Lever Throttle Linkage gt Choke Linkage Governor Spring F Governed Idle Spring G Control Bracket HO Regulating Pin J z S K Governor Gear Shaft L Idle Solenoid Digital Linear Actuator DLA Linkage Retaining m Electronic Governor rm This governor design works as follows e Centrifugal force acting on rotating governor gear assembly causes flyweights to move outward as speed increases Governor
52. cal sequence and or an F at end of cycle SAM is probably bad Recheck all connections check condition of tester battery and repeat test If you get sign and or F again in retest replace that SAM 3 Disconnect yellow and brown tester leads from long module leads Connect brown tester lead to short brown module lead Connect yellow tester lead to short yellow or pink module lead Leave red and green leads connected Repeat step 2 To test DSAM and ASAM using 25 761 40 S tester NOTE Do not allow alligator clip leads to touch each other NOTE SAM must be at room temperature when tested Disconnect all SAM leads isolating it from main wiring harness and ignition module s Testing may be performed with module mounted or loose NOTE Some modules contain two black ground leads with one containing a white stripe Do not connect to black white lead with bullet connector or a Fail test result will occur regardless of actual condition Test procedure for twin cylinder SAMs will vary slightly depending on whether module is analog ASAM or digital DSAM 1 Check SAM part number stamped on end of housing a If itis an ASAM 24 584 09 or 24 584 10 separate short yellow and brown leads from long ones Each set will be tested separately Connect tester to SAM as follows 46 KohlerEngines com e Yellow tester lead to long yellow module lead e Brown tester lead to long brown module lead e Red tester lead to red
53. cer washer on external threads Apply Loctite 2429 removable onto threads Install four supports 2 Tighten supports with a torque wrench to 9 9 N m 88 in Ib Debris screen will be installed to supports after blower housing is in place E Hydmuicufer m E CH Ped Ll o Valve Cover O ring P 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 location in crankcase Do not use a magnet Valve Stem Seals These engines use valve stem seals on intake valves and occasionally on exhaust valves Always use a new seal whenever valve is removed or if seal is deteriorated or damaged in any way Never reuse an old seal KohlerEngines com fT Reassembly 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 Cylinder Head 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
54. ch which grounds modules to stop engine e 2 spark plugs Spark Plug s B Oil Pressure Switch Oil Sentry Green Flywheel Stator T Non Smart Spark Assembly Lm ignition Module Ignition Rectifier Regulator ol Sentry Kill Green K Violet B Connector Starter Solenoid Tang Starter Solenoid Stud D L Solenoid Shift Starter Assembly wmm a mn e meme n mem v Court Sno B AG White Kill Rectifier Regulator Key Switch Battery Positive Light Remote Light Black Ground Intake Manifold Screw Oil Sentry Panel Key Switch Ground Battery Negative 24 690 30 Rev D KohlerEngines com 3 Electrical System Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with Variable Ignition Timing SMART SPARK 38 KohlerEngines com 24 690 30 Rev D Electrical System Smart Spark Advance Ignition System SMART SPARK equipped engines utilize an electronic capacitive discharge ignition system with electronic spark advance A typical application consists of following components e magnet assembly which is permanently affixed to flywheel e 2 electronic capacitive discharge ignition modules which mount on engine crankcase e 1 spark advance module which mounts to engine shrouding e 1 12 volt battery which supplies current to spark advance module e 1 kill switch or key switch which grounds spark advance module to stop engine e 2 spark plugs LA OiPresueSwin B OSen
55. charge 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 Make sure clutch or transmission is disengaged or placed Or in neutral This is especially important on equipment with Engine 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 50 KohlerEngines com 24 690 30 Rev D INERTIA DRIVE ELECTRIC STARTERS Inertia Drive Starter Components B X StpNut D Ant DriftSpring F BDrivePinon Retaining Ring H Spring Retainer Drive Nut Collar When power is applied to starter armature rotates As armature rotates drive pinion moves out on drive shaft splines and into mesh with flywheel ring gear When pinion reaches end of drive shaft it rotates flywheel and cranks engine Dust Cover Stop Gear Spacer E Dust Cover Spacer 24 690 30 Rev D Starter System When engine starts flywheel rotates faster than starter armature and drive pinion This moves drive pinion out of mesh with ring gear and into retracted position When power is removed from starter armature stops rotating and drive pinion is held in retracted position by anti drift spring Starter Drive Servic
56. com 32 987 33 013 mm 1 2987 1 2997 in 6 5 mm 0 2559 in 7 038 7 058 mm 0 2771 0 2779 in 29 37 29 63 mm 1 1563 1 1665 in 45 1 5 mm 0 0591 in 6 970 6 988 mm 0 2744 0 2751 in 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 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 seals intake valve only 4 Repeat above procedure for other cylinder head Do not interchange parts from one cylinder head to other After cleaning check flatness of cylinder head and corresponding top surface of crankcase using a surface plate or piece of glass and feeler gauge For all except 83 mm bore maximum allowable out of flatness is 0 076 mm 0 003 in For 83 mm bore maximum allowable out of flatness is 0 1 mm 0 004 in 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
57. cting rod 4 Use aflat washer with correct I D to slip on capscrew and approximately 1 in O D Assemble capscrew and washer to joint surface of rod KohlerEngines com TO Troubleshooting TROUBLESHOOTING GUIDE When troubles occur be sure to check simple causes which at first may seem too obvious to be considered For example a starting problem could be caused by an empty fuel tank Some general common causes of engine troubles are listed below and vary by engine specification Use these to locate causing factors Engine Cranks But Will Not Start Battery connected backwards Blown fuse Carburetor solenoid malfunction Choke not closing Clogged fuel line or fuel filter Diode in wiring harness failed in open circuit mode DSAI or DSAM malfunction Empty fuel tank Faulty electronic control unit Faulty ignition coil s Faulty spark plug s Fuel pump malfunction vacuum hose clogged or leaking Fuel shut off valve closed Ignition module s faulty or improperly gapped Insufficient voltage to electronic control unit Interlock switch is engaged or faulty Key switch or kill switch in OFF position Low oil level Quality of fuel dirt water stale mixture e SMART SPARK malfunction e Spark plug lead s disconnected Engine Starts But Does Not Keep Running e Faulty carburetor Faulty cylinder head gasket Faulty or misadjusted choke or throttle controls Fuel pump malfunction vacuum hose
58. d only by qualified LPG NG system technicians Improperly installed and maintained LPG NG equipment could cause fuel supply system or other components to malfunction causing gas leaks Observe federal state and local laws governing LPG NG fuel storage and systems This engine is certified to operate on LPG or LPG NG LPG Engines LPG from an appropriate LPG fuel tank supplied separately is required to operate this engine NG Engines NG from an approved system or source of supply can be used to operate this engine 4 KohlerEngines com 24 690 30 Rev D Engine Dimensions 421 01 18 575 14 77 je 302 58 14 77 582 11 813 582 ALTERNATE OIL 90 00 ER FILL LOCATION CLEAN 2 362 COVER REMOVAL 11 55 455 f M 470 86 18 538 FUEL 1 FILTER SOLENOID SHIFT STARTER eo 142 04 92 10 i 4X 10 30 406 1 e18 5 502 3 eze ve MOUNTING HOLES OIL FILTER ENGINE REMOVAL L 184 15 e MOUNTING 1 7 250 HOLE A l 287 09 11 303 MOUNTING HOLE A 28 58 1 125 18 HP 3 8 16 UNC 2B INCH 17 00 0 669 DEEP 301 95 142 88 5 625 B C Specifications Dimensions in millimeters Inch equivalents shown in LIFTING STRAP SPARK ADVANCE MODULE STANDARD ON SOME MODELS qui d EET rm HL 2X OIL DRAIN PLUG 3 8 N P T INCH MOUNTING HOLE 3 504 468 28 18 436 20 28 HP 4
59. d to separate small metal retainers Then unsnap fan from remaining mounting posts 2 Remove screws and fan 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 end play 24 690 30 Rev D Bp Fm ole E Flywheel F Magnet 1 Backing Piae J Woodruff Key Ring Support rm Metal Debris Screen Disassembly Inspection and Service T 1 N IRIS Flywheel Screw Wash Metal Debris Screen 1 Use a flywheel strap wrench or holding tool 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 gear as a serviceable part Replace flywheel if ring gear is damaged R
60. dard 7 048 mm 0 2775 in 0 25 mm O S 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 gt Values are in Metric units Values in parentheses are English equivalents 24 690 30 Rev D 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 t Into Aluminum OG ra Tightening Torque N m in Ib 20 8 32 2 3 20 10 24 3 6 3 10 32 1 4 20 1 4 28 5 16 18 17 0 5 16 24 18 7 3 8 16 29 4 3 8 24 33 9 N Co N a 0 N D G m O D NO AJI G o W y Ol G Q o Co 18 7 22 6 39 6 35 7 9 OO O NO RO K O1 B L O O eet ap e N co a A M OO O o EV O N EN NNNM co O Co O1 O1 Co OIOI O OQ NO o O O O O 6 32 5 0 N O o O Ql St SNA N NO 30 Noncritical Fasteners Into Aluminum Tightening Torque N m ft Ib 10 21 7 16 27 1 20 47 5 35 66 4 49 81 4 60 M12 36 6 27 47 5 35 82 7 61 116 6 86 139 7 103 M14 58 3 43 76 4 56 131 5 97 184 4 136 219 7 162 Torque Conversions N m in Ib x 0 113 in Ib N m x 8 85 N
61. dules KohlerEngines com 179 Reassembly External Engine Components B AT vaporizer BI Lockofffiter C Regulator D 1 inner Bafe J Breather Reed K Breather Gasket L M BreatherTue N OiSenty O Fie P AirCleaner Q ore RR Nipple s OlCoe T Electric Starter V iting Bracket V Fred Guard W Blower Housing X Debris Sield Co O KohlerEngines com 24 690 30 Rev D Install Breather Cover and Inner Baffles Breather Cover Details and Torque Sequence Install These Screws First RTV sealant was used on early models between breather cover and crankcase A gasket with imprinted sealant beads is now used and recommended Install as follows 1 Be sure sealing surfaces of crankcase and breather cover are clean of old gasket material or RTV sealant 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 Install breather reed and breather reed retainer onto crankcase and secure with screw Hold assembly in line when tightening Torque screw to 3 9 N m 35 in Ib 4 Insert breather filter into position in crankcase Make sure no filter strands are on sealing surface o Install new breather gasket 6 Carefully position breather cover on crankcase Install first two screws at positions shown and finger tighten at this time 7 Install inner baffles using two remaining screws and finger
62. e Style A NOTE Do not over tighten vise as this can distort drive pinion 1 Remove starter from engine and remove dust cover 2 Hold drive pinion in a vice with soft jaws when removing or installing stop nut Armature will rotate with nut until drive pinion stops against internal spacers 3 Remove stop nut stop gear spacer anti drift spring dust cover spacer and drive pinion 4 Clean splines on drive shaft thoroughly with solvent Dry splines thoroughly 5 Apply a small amount of Kohler electric starter drive lubricant to splines Use of other lubricants may cause drive pinion to stick or bind 6 Apply a small amount of Loctite 271 to stop nut threads 7 Install drive pinion dust cover spacer anti drift spring stop gear spacer and stop nut Torque stop nut to 17 0 19 2 N m 150 170 in Ib Reinstall dust cover Style B 1 Rubber dust cover has a molded lip on inside that snaps into a groove in dust cover spacer Turn drive pinion clockwise until it reaches fully extended position While holding it in extended position grasp tip of dust cover with a pliers or vise grip and pull it free from spacer 2 Disassemble snap ring removal tool 3 Grasp spring retainer and push it toward starter compressing anti drift spring and exposing retaining ring 4 Holding spring retainer in retracted position assemble inner halves of removal tool around armature shaft with retaining ring in inner groove Slide
63. e e Worn or broken piston rings e Worn valve stems valve guides Oil Leaks from Oil Seals Gaskets Breather reed broken Loose or improperly torqued fasteners Piston blow by or leaky valves Restricted exhaust 24 690 30 Rev D Clogged broken or inoperative crankcase breather Troubleshooting EXTERNAL ENGINE INSPECTION NOTE It is good practice to drain oil at a location away from workbench Be sure to allow ample time for complete drainage Before cleaning or disassembling engine make a thorough inspection of its external appearance and condition This inspection can give clues to what might be found inside engines and cause when it is disassembled e Check for buildup of dirt and debris on crankcase cooling fins grass screen and other external surfaces Dirt or debris on these areas can cause overheating e Check for obvious fuel and oil leaks and damaged components Excessive oil leakage can indicate a clogged or inoperative breather worn or damaged seals or gaskets or loose fasteners e Check air cleaner cover and base for damage or indications of improper fit and seal e Check air cleaner element Look for holes tears cracked or damaged sealing surfaces or other damage that could allow unfiltered air into engine A dirty or clogged element could indicate insufficient or improper maintenance e Check carburetor throat for dirt Dirt in throat is further indication that air cleaner was not functio
64. e is 0 ohms Stator is shorted replace Resistance is infinity Stator is open replace ohms 4 With engine stopped measure resistance from each stator lead to ground using an ohmmeter Condition Conclusion ou is infinity ohms Stator is OK not shorted no continuity to ground Resistance or continuity Stator leads are shorted to measured ground replace 48 KohlerEngines com 24 690 30 Rev D Electrical System 3 Amp 70 Watt Lighting Stator 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 To test charging system for no charge to battery To test charging system for no lights 1 With engine running in fast setting measure voltage 1 Make sure lights are not burned out across battery terminals using a DC voltmeter Condition Conclusion Condition SOHEIUSIOR Burned out lights Voltage is more than 12 5 Charging system is OK volts Voltage is 12 5 volts or Serra 2 Disconnect lighting lead from wiring harness less probably faulty Continue With engine running in fast setting measure voltage testing stator and diode from lighting lead to ground using an AC voltmeter 2 T Condition Conclusion Remove connector from rectifier regulator Wi engine running in fast position measure AC voltage de is 15 volts or EIE across stator leads using an AC
65. e with screws and torque to 22 6 N m 200 in Ib 2 Install regulator to bracket with screws and torque to 24 4 N m 216 in Ib Attach vacuum line and fuel lines to regulator 3 Secure vaporizer to bracket if equipped with 2 screws Torque 3 8 in screw to 29 4 N m 260 in Ib and 1 4 in screw to 7 9 N m 70 in Ib 4 Attach fuel lines from regulator to lock off filter and carburetor 82 KohlerEngines com Control Bracket Components SE a Pr C 2S SF in 1 a Jp ln di M 4 X go us PORN us mn lt A LO A LAS ess E icy E gt m Ma y gt P4 gt y j L z 3 Y Mel Control Bracket EN Spring D Governor Lever KA Choke Linkage Install External Governor Controls 1 Install governor lever onto governor cross shaft 2 Make sure throttle linkage is connected to governor lever and throttle lever on carburetor 3 Move governor lever toward carburetor as far as it will go wide open throttle and hold in position A Insert a nail into hole on cross shaft and rotate shaft counterclockwise as far as it will turn then torque nut to 6 8 N m 60 in Ib Install Throttle amp Choke Controls 1 Connect choke linkage to carburetor and choke actuator lever 2 Mount main control bracket and air cleaner support bracket if used to cylinder heads using four screws Torque screws to 10 7 N m 95 in Ib into new holes or 7 3 N m 65 in Ib into used holes 3 Connect govern
66. ea where leaking gas could accumulate and endanger safety of persons in area To ensure personal safety installation and repair of LPG NG fuel supply systems must be performed only by qualified LPG NG system technicians Improperly installed and maintained LPG NG equipment could cause fuel supply system or other components to malfunction causing gas leaks Observe federal state and local laws governing LPG NG fuel storage and systems 1 Disconnect ground lead if equipped 2 Remove carburetor mounting screws or nuts 3 Remove carburetor throttle linkage and governor lever as an assembly 4 Remove carburetor gasket 5 If necessary carburetor throttle linkage and governor lever can be separated Reattach bushings to linkage following separation to avoid losing them Remove Oil Sentry if equipped 1 Disconnect lead from Oil Sentry switch 2 Remove Oil Sentry switch from breather cover Remove Electric Starter Motor 1 Disconnect leads from starter 2 Remove screws 3 Remove starter assembly and any spacers if used Remove Outer Baffles and Blower Housing 1 Disconnect plug from rectifier regulator on blower housing 2 Usetip of dipstick or a similar small flat tool to bend locking tang then remove B center lead from terminal plug This will allow blower housing to be removed without disturbing wiring harness 3 Rectifier regulator does not have to be detached from blower housing If e
67. econdary Pivot Pin another Two different styles of regulators are used Secondary Lever Assembly Adjustment Screw Floor B DIP H Dr gt S based upon system involved Although basic design Vacuum Lock Sprin and operating principles are similar due to system differences regulators should not be interchanged Secondary Diaphragm Vacuum Lock Diaphragm Assembly T operation and general service information for each style of regulator Detailed service repair instructions are included in rebuild kit for each regulator Following are separate sections covering theory of orx Head Screw with Split Lock Washer LPG NG Passag ing e Fillister Head Screw g a Primary Pivot Pin Primary Lever Assembly Expansion Plug i i Secondary i Diaphragm Sprin LPG NG Primary Are y Secondary Lever Spring AA Secondary Valve Primary Spring Primary Diaphragm Assembly Diaphragm Gasket Passage to Secondary Valve 1 8 27 NPT Plug 24 690 30 Rev D KohlerEngines com 27 Fuel System LPG NG vapor enters regulator then passes into primary area where pressure is reduced from up to 1724 kPa 250 psi at tank to 31 kPa 4 5 psi Fuel pressure against diaphragm overcomes spring and as movement increases spring will close lever Primary diaphragm breather is vented to secondary chamber so that rupture of this diaphragm would direct fuel into carburetor Fuel now moves through passage past secondary valve into sec
68. ecting Rod Cap Fastener torque in increments 8 mm straight shank 200 in Ib 22 7 N m 8 mm step down 14 7 N m 130 in Ib 11 3 N m 6 mm straight shank 100 in Ib Values are in Metric units Values in parentheses are English equivalents Exceeding maximum angle of operation may cause engine damage from insufficient lubrication Lubricate threads with engine oil prior to assembly 6 Any and all horsepower hp references by Kohler are Certified Power Ratings and per SAE J1940 8 J1995 hp standards Details on Certified Power Ratings can be found at KohlerEngines com 6 KohlerEngines com 24 690 30 Rev D Specifications TORQUE SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 CH730 CH740 Crankcase Breather Cover Fastener 7 3 N m 65 in Ib Oil Drain Plug 13 6 N m 10 ft Ib 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 9 9 N m 88 in Ib Flywheel Retaining Screw 66 4 N m 49 ft Ib Governor 6 8 N m 60 in Ib Ignition opark Plug 2 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 Sentry Pressure Switch 4 5 N m 40 i
69. ed 3 Install rotor 4 Install oil pump body to closure plate and secure with screws Torque screws as follows a Install fastener into screw location 1 and lightly tighten to position pump b Install fastener into screw location 2 and fully torque to recommended value c Torque fastener in screw location 1 to recommended value First Time Installation 10 7 N m 95 in Ib All Reinstallations 6 7 N m 60 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 66 KohlerEngines com Oil Pump Assembly Style B Oil pump is mounted inside closure plate If service is required continue with Disassembly Inspection and Reassembly Disassembly 1 Remove screws 2 Liftoil pump assembly from closure plate Remove outer gerotor gear from closure plate 3 Ensure ball and spring remain installed in pressure relief hole of closure plate 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 closure plate 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 restrictio
70. eeve Bearing crankcase Running Clearance New 0 03 0 09 mm 0 0012 0 0035 in Bore in closure plate New 40 987 40 974 mm 1 6136 1 6131 in Crankshaft Bore in closure plate to Crankshaft Running Clearance New 0 039 0 074 mm 0 0015 0 0029 in Flywheel End Main Bearing Journal O D New 40 913 40 935 mm 1 6107 1 6116 in O D Max Wear Limit 40 84 mm 1 608 in Max Taper 0 022 mm 0 0009 in Max Out of Round 0 025 mm 0 0010 in Closure Plate End Main Bearing Journal O D New 40 913 40 935 mm 1 6107 1 6116 in O D Max Wear Limit 40 84 mm 1 608 in Max Taper 0 022 mm 0 0009 in Max Out of Round 0 025 mm 0 0010 in Connecting Rod Journal O D New 35 955 35 973 mm 1 4156 1 4163 in O D Max Wear Limit 35 94 mm 1 415 in Max Taper 0 018 mm 0 000 in Max Out of Round 0 025 mm 0 0010 in T I R PTO End Crank in Engine 0 279 mm 0 0110 in Entire Crank in V Blocks 0 10 mm 0 0039 in Cylinder Bore Bore I D New 77 000 77 025 mm 80 000 80 025 mm 82 988 83 013 mm 3 0315 3 0325 in 3 1496 3 1506 in 3 2672 3 2682 in Max Wear Limit 77 063 mm 80 065 mm 83 051 mm 3 0340 in 3 1522 in 3 2697 in Max Out of Round 0 12 mm 0 0047 in 0 05 mm 0 0020 in Values are in Metric units Values in parentheses are English equivalents 24 690 30 Rev D KohlerEngines com 9 Specifications CLEARANCE SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 CH730 CH740 Cyl
71. elt 6 Hold base of tool with a 1 1 8 wrench and turn center screw clockwise with a 1 2 or 13 mm wrench to draw spring retainer up around retaining ring Stop turning when resistance increases Disassemble and remove tool T Reinstall dust cover Starter Disassembly 1 Remove drive components following instructions for servicing drive 2 Locate small raised line on edge of drive end cap On starters with style A commutator end caps it will be aligned with a pre marked line on starter frame Frame is not pre marked on starters with style B end caps Place a piece of masking tape on frame and mark a line on tape in line with raised line on end cap 3 Remove thru bolts 4 Remove commutator end cap with brushes and brush springs style A Style B end caps remove as a separate piece with brushes and carrier remaining in frame 5 Remove drive end cap 6 Remove armature and thrust washer if equipped from inside starter frame 7 Remove brush carrier assembly from frame style B starters Brush Replacement Style A NOTE Use a brush holder tool to keep brushes in pockets A brush holder tool can easily be made from thin sheet metal 1 Remove brush springs from pockets in brush holder 2 Remove self tapping screws negative brushes and plastic brush holder 3 Remove nut and fiber washer from stud terminal Remove stud terminal with positive brushes and plastic insulating bushing from end cap
72. emove Stator and Backing Plates 1 Remove screws securing backing plates and stator wire bracket if equipped Remove backing plates and stator wire bracket 2 Remove screws and stator KohlerEngines com 63 Disassembly Inspection and Service Crankcase Components e Oi Gerotor Gears il Seal Closure Plate Style A C Style A Dipstick Tube Oil Pick Up Tube Oil Pump Assembly D E JB d Camshaft J PistonPin K Piston Ring Set Piston Pin Retainer LDNCCNNEIR Ris dE Outer Gerotor Gear Oil Drain Plug Governor Cross Shaft Closure Plate Style B T Style B Oil Pump Cover O ring Oil Pump Assembly u Ball Style B Spring Style B w Style B Style B Y Oil Pick Up Tube Style B Remove Closure Plate Assembly Inspection iH e Jnspect oil seal in closure plate and remove it if it is worn 1 Remove screws securing closure plate to crankcase or damaged Refer to Install Closure Plate Oil Seal in 2 Locate splitting tabs cast into perimeter of closure Reassembly for new oil seal installation plate Insert drive end of a 1 2 in breaker bar Inspect main bearing surface for wear or damage Refer between top splitting tab and crankcase Hold to specifications Replace closure plate assembly if handle horizontal and pull toward you to break RTV required seal If necessary pry at bottom tabs also Do not pry on sealing surfaces as this could cause leaks Carefully pull closure plate from crankcase 64 KohlerEngines c
73. from armature 13 Clean parts as required Inspection Drive Pinion Check 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 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 o4 KohlerEngines com Armature Components and Details emo B Commutator O D B Mica Insulation Insulation Check D Armature Coil 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
74. g 1 Insert an ammeter in B lead from rectifier regulator at high rate With engine running at 3600 RPM and B at 1 With engine running at 3600 RPM measure voltage terminal on rectifier regulator to ground using a DC from B lead to ground using a DC voltmeter voltmeter Condition Conclusion If voltage is 13 8 volts or more place a minimum load of 5 amps turn on lights if 60 watts or more or Voltage is 14 7 volts or Charging system is OK place a 2 5 ohm 100 watt resistor across battery less Battery is unable to hold terminals on battery to reduce voltage Observe charge service or replace ammeter Voltage is more than 14 7 Faulty rectifier regulator volts replace Condition Conclusion Charge rate increases Charging system is OK when load is applied and battery was fully charged Charge rate does not Test stator and rectifier increase when load is regulator steps 2 and 3 applied 2 Remove connector from rectifier regulator With engine running at 3600 RPM measure AC voltage across stator leads using an AC voltmeter Condition Conclusion Voltage is 28 volts or Stator is OK Rectifier more regulator is faulty replace Voltage is less than 28 Stator is faulty replace volts Test stator further using an ohmmeter steps 3 and 4 3 With engine stopped measure resistance across stator leads using an ohmmeter Condition Conclusion Resistance is 0 1 0 2 Stator is OK ohms Resistanc
75. g lead loose Engine Will Not Idle Engine overheated Faulty spark plug s Idle fuel adjusting needle s improperly set Idle speed adjusting screw improperly set Inadequate fuel supply Low compression Quality of fuel dirt water stale mixture Restricted fuel tank cap vent Engine Overheats Cooling fan broken Excessive engine load Fan belt failed off Faulty carburetor High crankcase oil level Lean fuel mixture Low cooling system fluid level Low crankcase oil level Radiator and or cooling system components clogged restricted or leaking Water pump belt failed broken Water pump malfunction Engine Knocks Excessive engine load Hydraulic lifter malfunction Incorrect oil viscosity type Internal wear or damage Low crankcase oil level Quality of fuel dirt water stale mixture 24 690 30 Rev D Engine Loses Power e Dirty air cleaner element e Engine overheated e Excessive engine load e Restricted exhaust e Faulty spark plug s e High crankcase oil level e Incorrect governor setting e Low battery e Low compression e Low crankcase oil level e Quality of fuel dirt water stale mixture Engine Uses Excessive Amount of Oil e Loose or improperly torqued fasteners e Blown head gasket overheated e Breather reed broken e Clogged broken or inoperative crankcase breather e Crankcase overfilled e Incorrect oil viscosity type e Worn cylinder bor
76. get or F sign again in retest replace SAM BATTERY CHARGING SYSTEM NOTE Observe 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 Some engines utilize a 3 amp unregulated system with optional 70 watt lighting circuit 24 690 30 Rev D Electrical System 15 20 25 Amp Regulated Charging System Stator otator 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 w
77. heads are being replaced Do not intermix components Heads secured with screws NOTE Match numbers embossed on cylinder heads and crankcase 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 lightly lubricate threads of bolts with engine oil but be careful not to get any oil on gasket sealing surfaces Thread bolts in until finger tight 4 Torque screws in two stages first to 22 6 N m 200 in Ib 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 Ifall studs were left intact go to Step 5 If any studs were disturbed or removed install new studs as described in Step 3 Do not use reinstall any loosened or removed studs 78 KohlerEngines com 3 Install new mounting stud s into crankcase a Thread and lock two 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 S
78. hetic oil is recommended for use in LPG NG fueled engines Non synthetic oil must be low ash rated oil STORAGE If engine will be out of service for 2 months or more follow procedure below Oils including synthetic must meet API American ahi Petroleum Institute service class SG SH SJ or SL L eee een ae a MEE E u ale at time of engine oil into cylinder s Replace spark plug s and a SR A crank engine slowly to distribute oil Low ash is defined as less than 1 sulfated ash 2 Disconnect negative battery cable 3 Separate LPG tank from unit and store separately in an area designated for safe LPG tank storage 4 Store engine in a clean dry place 20 32 40 50 60 0 10 FUEL RECOMMENDATIONS Explosive Fuel can cause fires and severe burns _ If a gaseous odor is detected ventilate area and contact an authorized service technician LPG is extremely flammable and is heavier than air and tends to settle in low areas where a spark or flame could ignite gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area NG is extremely flammable is lighter than air and rises Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area To ensure personal safety installation and repair of LPG NG fuel supply systems must be performe
79. in 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 Detonation damage occurs when a portion of fuel charge ignites spontaneously from heat and pressure shortly after ignition This creates two flame fronts which meet and explode to create extreme hammering pressures on a specific area of piston Detonation generally occurs from using low octane fuels Preignition or ignition of fuel charge before timed spark can cause damage similar to detonation Preignition damage is often more severe than detonation damage 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 a
80. inder Head Max Out of Flatness 0 076 mm 0 003 in 0 1 mm 0 004 in Governor Governor Cross Shaft to Crankcase Running Clearance 6 mm Shaft 0 013 0 075 mm 0 0005 0 0030 in 8 mm Shaft 0 025 0 126 mm 0 0009 0 0049 in Cross Shaft O D 6 mm Shaft New 5 975 6 012 mm 0 2352 0 2367 in Max Wear Limit 5 962 mm 0 2347 in 8 mm Shaft New 7 949 8 000 mm 0 3129 0 3149 in Max Wear Limit 7 936 mm 0 3124 in Governor Gear Shaft to Governor Gear 0 015 0 140 mm 0 0006 0 0055 in Running Clearance Gear Shaft O D New 5 990 6 000 mm 0 2358 0 2362 in Max Wear Limit 5 977 mm 0 2353 in Ignition Spark Plug Gap 0 76 mm 0 03 in for All Except NG with CD Fixed 0 51 mm 0 02 in for NG with CD Fixed Module Air Gap 0 28 0 33 mm 0 011 0 013 in Piston Piston Rings and Piston Pin Piston to Piston Pin Running Clearance 0 006 0 017 mm 0 0002 0 0007 in Pin Bore I D New 17 006 17 012 mm 0 6695 0 6698 in Max Wear Limit 17 025 mm 0 6703 in 16 995 17 000 mm 0 6691 0 6693 in Max Wear Limit 16 994 mm 0 6691 in Top Compression Ring to Groove Side Clearance 0 040 0 080 mm 0 030 0 076 mm 0 025 0 048 mm 0 0016 0 0031 in 0 0012 0 0030 in 0 0010 0 0019 in Middle Compression Ring to Groove Side Clearance 0 040 0 080 mm 0 030 0 076 mm 0 015 0 037 mm 0 0016 0 0031 in 0 0012 0 0030 in 0 0006 0 0015 in Oil Control Ring to Groove Side Clearance 0 060 0 202 mm 0 046 0 196
81. ining clip at end of DLA shaft slide DLA bracket assembly back until throttle plate is fully open Torque mounting plate screws to 2 5 N m 22 in Ib Troubleshooting Engine Starts But Will Not Continue to Run 1 Check linkage connection between DLA and throttle plate 2 Verify DLA initializes when power is supplied key switch in start or run position 3 Test potentiometer wiper output voltage if equipped 4 Test SPST switch if equipped 5 Check wire harness and connections Engine Does Not Run At Expected Speed 1 Check to see that throttle linkage and DLA have full range of motion having no mechanical interference 2 Test potentiometer wiper voltage if equipped 3 Test SPST switch if equipped KohlerEngines com 31 Lubrication System This engine uses a full pressure lubrication system which delivers oil under pressure to crankshaft camshaft connecting rod bearing surfaces and hydraulic valve lifters A high efficiency gerotor oil pump maintains high oil flow and oil pressure even at low speeds and high operating temperatures A pressure relief valve limits maximum pressure of system Closure plate must be removed to service oil pickup pressure relief valve and oil pump Lubrication Components A Pressin Dipstek B Thread On Dipstick c Oise b OlFicm E oncooer F Ole G Oibrain Pug H Back Side OIL RECOMMENDATIONS Refer to Maintenance CHECK OIL LEVEL NOTE To p
82. ion 5 Fill crankcase with new oil Level should be at top of indicator on dipstick 6 Reinstall oil fill cap dipstick and tighten securely 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 follow these steps 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 fuel needle or idle speed adjusting screw as necessary Testing Engine It is recommended engine be operated on a test stand or bench prior to installation in piece of equipment 1 Setengine up on a test stand Install an oil pressure gauge Start engine and check to be certain 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 24 690 30 Rev D KohlerEngines com Reassembly 85 86 KohlerEngines com 24 690 30 Rev D 24 690 30 Rev D KohlerEngines com 87 1P24 690 30 10336 9 2015 by Kohler Co All rights reserved 8 85612 88 KohlerEngines com 24 690 30 Rev D
83. ional rear screws must be removed if engine contains a rear air cleaner support bracket o Remove bracket then remove base and gasket while carefully pulling rubber breather tube through base 6 Remove rubber breather tube from breather cover 58 KohlerEngines com Remove LPG NG Components Explosive Fuel can cause fires and severe burns If a gaseous odor is detected ventilate area and contact an authorized service technician LPG is extremely flammable and is heavier than air and tends to settle in low areas where a spark or flame could ignite gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area NG is extremely flammable is lighter than air and rises Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area To ensure personal safety installation and repair of LPG NG fuel supply systems must be performed only by qualified LPG NG system technicians Improperly installed and maintained LPG NG equipment could cause fuel supply system or other components to malfunction causing gas leaks Observe federal state and local laws governing LPG NG fuel storage and systems 1 Remove fuel lines and vacuum line from regulator Remove screws securing regulator and bracket 2 For LPG engines remove fuel lines from vaporizer and lock off filter Remove
84. ire or metal grounding strap Testing of rectifier regulator may be performed as follows using appropriate Rectifier Regulator Tester To test 4 15 amp rectifier regulators To test 20 25 amp rectifier regulators 1 Connect tester ground lead with spring clamp to 1 20 amp Connect single lead adapter in between B body of rectifier regulator being tested center terminal of rectifier regulator being tested 2 Connect tester red lead to B terminal of rectifier and squared single end of tandem adapter lead regulator and 2 black tester leads to 2 AC terminals 25 amp Connect squared single end of tandem lead 3 Plug tester into proper AC outlet power for tester adapter to B center red lead of rectifier regulator being used Turn on power switch POWER light being tested should be illuminated and 1 of 4 status lights may be 2 Connect tester ground lead with spring clamp to on as well This does not represent condition of part body of rectifier regulator 4 4 amp Press TEST button until a click is heard and 3 Connect red lead and 1 of black leads to pair of then release Momentarily either HIGH LOW or terminals on open end of tandem adapter lead SHORT light will flash connections are not location specific 15 amp Press TEST button until a click is heard and 4 Connect remaining black lead from tester to 1 of then release Momentarily 1 of 4 status lights will outer AC terminals on rectifier regulator illuminate indicating c
85. lated silver colored fasteners b If correct voltage is still not indicated check harness connector terminal for a good connection and crimp to lead Then trace power source circuit back through harness key switch etc looking for any poor connections or faulty circuits Condition Possible Cause Conclusion Incorrect voltage is measured Connect black voltmeter lead directly to negative post of battery and test voltage again in both key positions If correct voltage is still not indicated check harness connector terminal for a good connection and crimp to lead Then trace power source circuit back through harness key switch etc looking for any poor connections or faulty circuits Correct voltage is measured Voltage Check ground circuit connections If ground screw bolt or any other fasteners in ground circuit are black oxide coated replace them with zinc plated silver colored fasteners 2 Disconnect all SAM leads isolating it from engine Test SAM according to style with tester 25 761 21 S tests ASAM style modules only or tester 25 761 40 S tests both ASAM and DSAM style modules Use test instructions following or those provided with SEA If SAM tests bad replace it 3 Reattach SAM leads verifying a snug fit at ignition module terminals If any connections do not feel snug disconnect lead lightly pinch female terminal with a pliers and recheck fit 4 Seal base of ignition module connections with G
86. le is faulty and should within ranges specified in table be replaced 5 Check and or adjust ignition module air gap s An air gap of 0 28 0 33 mm 0 011 0 013 in must be maintained under all three legs of ignition module s Checking adjusting should be performed with parts at room temperature Condition Module was not loosened or replaced Possible Cause Ignition Module Air Gap Conclusion Check that specified air gap is present under all three legs If gap is correct reinstall second mounting screw removed earlier and recheck gap after tightening Module was loosened or replaced Ignition Module Adjust ignition module air gap a Adjust ignition module air gap 1 Turn flywheel magnet away from module position 2 Attach module to mounting legs pull it away from flywheel and tighten screws to hold it temporarily 3 Rotate flywheel so magnet is centered under module 4 Position a 0 30 mm 0 012 in feeler gauge between magnet and all three legs of module Ignition module air gap is critical to proper system performance Do not attempt to set it with a business card or folded microfiche card Use feeler gauge specified 5 Loosen mounting screws allow magnet to pull module down against feeler gauge and retighten mounting Screws 6 Rotate flywheel to remove feeler gauge position magnet back under module and recheck that specified gap minimum of 0 28 mm 0 011 in exists under each leg of module Whe
87. led properly in 1 Apply pipe sealant with Teflon Loctite PST 592 Thread Sealant or equivalent to stator mounting holes 2 Position stator aligning mounting holes so leads are at bottom towards crankcase 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 2 Install flywheel onto crankshaft being careful not to 3 Install and torque screws to 6 2 N m 55 in Ib shift woodruff key 4 Route stator leads in crankcase channel then install 3 Install screw and washer Dac ng pesce Mer e uo 4 Use a flywheel strap wrench or holding tool to hold Secure using screws Torque screws to 7 3 N m 65 in Ib Install Flywheel Damaging Crankshaft and Flywheel can cause personal injury Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions and procedures when installing flywheel NOTE Before installing flywheel make sure crankshaft taper and flywheel hub are clean dry and completely free of any lubricants Presence of lubricants can cause flywheel to be over stressed and damaged when screw is torqued to specifications flywheel Torque screw securing flywheel to crankshaft to 66 4 N m 49 ft Ib Install Flywheel Fan NOTE Position ears located at rear perimeter of fan in 1 2 rece
88. ll line on outer edge of venturi for proper orientation and reinstallation later C Loosen venturi retaining screw on side of carburetor body and lift out venturi Inspect overall condition of fuel enrichment hose attached to carburetor It must be free of cracks deterioration and damage Disconnect fuel enrichment hose from carburetor fittings to clean or check condition as required Replace with a new Kohler high pressure hose LP rated if condition is questionable in any way Secure new hose using new clamps Clean all parts as required use a good carburetor cleaner following manufacturer s instructions Blow clean compressed air through all passages Do not poke or probe into load block assembly as damage can be done resulting in serious operational problems Nikki Carburetor 1 2 24 690 30 Rev D Turn off fuel supply Remove air cleaner breather hose fuel line vacuum hose choke and throttle linkages Remove nuts carburetor and gaskets from engine Discard gaskets Remove fuel transfer chamber cover by removing screws Carefully remove cover and gasket Discard gasket Main jet is fixed and nonadjustable but may be accessed for cleaning by removing rear plug and sealing washer Discard washer In order to clean off idle transfer passages and carburetor thoroughly use a good carburetor cleaner and follow manufacturer s instructions Blow clean compressed air through passages and make sure all are
89. located on output shaft side of engine while intake lifters are located on fan side of engine Cylinder head number is embossed on outside of each cylinder head Inspection and Service Valve Details EXHAUST VALVE UM A 2 i m SEER T a a T BETS Dimension Intake Seat Angle 89 Disassembly Inspection and Service Remove screws or nuts and washers securing each cylinder head 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 position of push rods as either intake or exhaust and cylinder 1 or 2 Push rods should always be reinstalled in same positions Carefully remove push rods cylinder heads and head gaskets Remove lifters from lifter bores 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 INTAKE VALVE EXHAUST INSERT INTAKE INSERT Exhaust 89 Insert O D Guide Depth D Guide I D Valve Head Diameter F Valve Face Angle G Valve Margin Min Valve Stem Diameter 24 690 30 Rev D 36 987 37 013 mm 1 4562 1 4572 in 4 mm 0 1575 in 7 038 7 058 mm 0 2771 0 2779 in 33 37 33 63 mm 1 3138 1 3240 in 45 1 5 mm 0 0591 in 6 982 7 000 mm 0 2749 0 2756 in KohlerEngines
90. ly 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 Disconnect Spark Plug Leads NOTE Pull on boot only to prevent damage to spark plug lead 1 Disconnect leads from spark plugs 2 Shutoff fuel supply 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 and discard oil filter 4 An oil cooler is standard equipment on some models and an option on others It may be a cast aluminum housing part of oil filter adapter or attached to blower housing separated from oil filter adapter If equipped remove adapter and cooler 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 Unhook latches or loosen knob and remove cover 2 Remove wing nut from element cover 3 Remove element cover air cleaner element with precleaner and stud seal 4 Remove screws securing bracket and base Addit
91. m ft Ib x 1 356 ft Ib N m x 0 737 12 KohlerEngines com 24 690 30 Rev D Tools and Aids Certain quality tools are designed to help you perform specific disassembly repair and reassembly procedures By using these tools you can properly service engines easier faster and safer In addition you ll increase your service capabilities and customer satisfaction by decreasing engine downtime Here is a list of tools and their source SEPARATE TOOL SUPPLIERS Kohler Tools SE Tools Design Technology Inc Contact your local Kohler source of 415 Howard St 768 Burr Oak Drive supply Lapeer MI 48446 Westmont IL 60559 Phone 810 664 2981 Phone 630 920 1300 Toll Free 800 664 2981 Fax 630 920 0011 Fax 810 664 8181 TOOLS Description Source Part No Alcohol Content Tester Kohler 25 455 11 S For testing alcohol content 96 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 45
92. m 17 Troubleshooting CRANKCASE VACUUM TEST Ac F Carbon Monoxide can cause severe nausea fainting or death unn Avoid inhaling exhaust fumes Engine exhaust gases contain poisonous carbon Keep hands feet hair and clothing away from all monoxide Carbon monoxide is odorless colorless moving parts to prevent injury Never operate engine and can cause death if inhaled with covers shrouds or guards removed Rotating Parts can cause severe injury Stay away while engine is in operation A partial vacuum should be present in crankcase when engine is operating Pressure in crankcase normally caused by a clogged or improperly assembled breather can cause oil to be forced out at oil seals gaskets or other available spots Crankcase vacuum is best measured with either a water manometer or a vacuum gauge Complete instructions are provided in kits To test crankcase vacuum with manometer To test crankcase vacuum with vacuum pressure gauge 1 Insert rubber stopper into oil fill hole Be sure pinch 1 Remove dipstick or oil fill plug cap clamp is installed on hose and use tapered adapters 5 Install adapter into oil fill dipstick tube opening to connect hose between stopper and one upside down over end of a small diameter dipstick manometer tube Leave other tube open to tube or directly into engine if a tube is not used atmosphere Check that water level in manometer is Insert barbed gauge fitting into hole in
93. middle and bottom There are 2 measurements that should be taken perpendicular to each other at all 3 locations 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 one hour of operation after a rebuild Final cleaning operation should always be a thorough scrubbing with a brush and hot soapy water Use a strong detergent capable of breaking down machining oil while maintaining a 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 24 690 30 Rev D Disassembly Inspection and Service Measuring Piston to Bore Clearance Piston Detail 6 mm 0 2362 in NOTE Do not use a feeler gauge to measure piston to bore clearance it will yield inaccurate measurements Always use a micrometer Before installing piston into cylinder bore it is necessary 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 6 mm 0 2362 in above bottom of pisto
94. mm 0 026 0 176 mm 0 0024 0 0080 in 0 0018 0 0077 in 0 0010 0 0070 in Top and Middle Compression Ring End Gap New Bore 0 25 0 45 mm 0 18 0 46 mm 0 25 0 56 mm 0 0098 0 0177 in 0 0071 0 0181 in 0 0100 0 0224 in Used Bore Max 0 77 mm 0 80 mm 0 94 mm 0 030 in 0 0315 in 0 037 in Thrust Face O D New 76 943 76 961 mm 79 943 79 961 mm 82 949 82 967 mm 3 0292 3 0299 in 3 1473 3 1480 in 3 2656 3 2664 in Max Wear Limit 76 816 mm 79 816 mm 82 822 mm 3 0242 in 3 1423 in 3 2606 in Piston Thrust Face to Cylinder Bore Running Clearance 0 039 0 082 mm New 0 0015 0 0032 in Values are in Metric units Values in parentheses are English equivalents Measure 6 mm 0 24 in above bottom of piston skirt at right angles to piston pin 10 KohlerEngines com 24 690 30 Rev D Specifications CLEARANCE SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 CH730 CH740 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 0 050 0 088 mm 0 0020 0 0035 in Intake Valve Guide I D New 7 038 7 058 mm 0 2771 0 2779 in Max Wear Limit 7 134 mm 0 2809 in Exhaust Valve Guide D New 7 038 7 058 mm 0 2771 0 2779 in Max Wear Limit 7 159 mm 0 2819 in Valve Guide Reamer Size Stan
95. module lead e Black tester lead to black or green module lead Remaining tester leads pink and brown with black band are not used for testing ASAMs b If itis a DSAM all except 24 584 09 or 24 584 10 connect tester as follows e Yellow tester lead to long yellow module lead e Brown tester lead to long brown module lead e Red tester lead to red module lead e Black tester lead to green or black module ground lead with eyelet terminal e Pink tester lead to short yellow or pink module lead e Brown tester lead with black band or terminal to short brown module lead 2 Recheck SAM part number noting last two digits Refer to table below or on tester faceplate to determine test number to be used 12 584 12 SAM Part 24 584 30 24 584 33 24 584 T 24 584 31 24 584 34 24 994 32 SAM Part 24 584 18 24 584 38 I E EEEE Teno 8 e De tester button IE zi FEE test number appears on display After a few seconds test number will flash three times and test will begin A reverse numerical sequence will be displayed starting with a 6 and progressing down to 1 followed by a P pass or F fail indicating condition of part If testing an ASAM return to step 1 and move yellow and brown tester leads to short set of module leads then repeat test 4 If you get a sign instead of numerical sequence and or an F at end of test cycle recheck all of connections check condition of tester battery and repeat test If you
96. n 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 for all except NG with CD fixed timing or 0 51 mm 0 02 in for NG with CD fixed timing 2 Install plug into cylinder head 3 Torque plug to 27 N m 20 ft Ib 34 KohlerEngines com Inspection Inspect each spark plug as it is removed from cylinder head Deposits on tip are an indication of general condition of piston rings valves and carburetor Normal and fouled plugs are shown in following photos Normal Plug taken om 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 ER by excess fuel oi Or E 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 30 Rev D Carbon Fouled u r 2 Soft sooty black deposits indicate incomplete combustion caused by a restricted air cleaner over rich carburetion weak ignition
97. n Ib Regulator Bracket Screws 22 6 N m 200 in Ib 24 4 N m 216 in Ib Solenoid Starter Mounting Hardware Nippondenso Starter m 53 79 in Ib Delco Remy Starter m 35 53 in Ib Nut Positive Brush Lead Nippondenso Starter m 71 106 in Ib Delco Remy Starter l m 71 97 in Ib Speed Control Bracket Fastener 10 7 Nm 95 in Ib into new holes 7 3 N m 65 in Ib into used holes Values are in Metric units Values in parentheses are English equivalents Lubricate threads with engine oil prior to assembly 24 690 30 Rev D KohlerEngines com M Specifications TORQUE SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 CH730 CH740 Starter Assembly Thru Bolt Inertia Drive 40 50 in Ib Nippondenso Solenoid Shift 40 84 in Ib Delco Remy Solenoid Shift l 49 79 in Ib Mounting Screw 135 in Ib Brush Holder Mounting Screw 22 29 in Ib Stator Mounting Screw 6 2 N m 55 in Ib Valve Cover Gasket Style Cover Fastener 3 4 N m 30 in Ib Black O ring Style Cover Fastener w Shoulder Screws 5 6 N m 50 in Ib w Flange Screws and Spacers 9 9 N m 88 in Ib Yellow or Brown O ring Style Cover Fastener w Integral Metal Spacers 6 2 N m 55 in Ib Vaporizer 3 8 in Screw 29 4 N m 260 in Ib 1 4 in Screw 7 9 N m 7O in Ib CLEARANCE SPECIFICATIONS CH18 CH20 CH23 CH25 CH640 CH730 CH740 Camshaft End Play w shim 0 076 0 127 mm 0 0030 0 0050 in Running Clearance 0 025
98. n all of terminals male and female with aerosol electrical contact cleaner to remove any old dielectric compound dark residue dirt or contamination Disconnect spark plug leads from spark plugs 3 Remove one mounting screw from each ignition module If mounting screws are black remove them both and discard Look in mounting hole with a flashlight and use a small round wire brush to remove any loose rust from laminations inside mounting hole 4 Use a digital ohmmeter to check resistance values and compare them to ignition module resistance table When testing resistance to laminations touch probe to laminations inside screw hole as some laminations have a rust preventative coating on surface which could alter resistance reading Condition All resistance values are within ranges specified in table Possible Cause Ignition Module Gap Ignition Module Resistance Table 24 584 03 Or 24 584 11 1 11 16 in High 24 584 15 S Or 24 584 36 S 2 1 16 in High Test From No From No From No Use Digital 1 to 4 2 to 4 3 to 4 Ohmmeter 24 584 03 945 to 149 to 3750 to 24 584 11 1175 ohms 166 ohms 7000 ohms 1 11 16 in H 24 584 15 S 890 to 119 to 5600 to 2 1 16 in H 1175 ohms 136 ohms 9000 ohms 24 584 36 S 590 to 183 to 8000 to 2 1 16 in H 616 ohms 208 ohms 40 000 ohms Conclusion Check and adjust ignition module gap At least 1 resistance value is not Ignition Module Ignition modu
99. n 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 closure plate 3 Reinstall O ring into groove in closure plate make sure it is fully seated in groove 4 Install oil pump inserting center shaft into corresponding recess in closure plate 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 Remove Camshaft Remove camshaft and shim 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 opecifications 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 24 690 30 Rev D Remove Connecting Rods with Pistons and Rings NOTE If a carbon ridge is present at top of either cylinder bore use a ridge reamer to
100. n skirt and perpendicular to piston pin 2 Use an inside micrometer telescoping gauge or bore gauge and measure cylinder bore Take measurement approximately 63 5 mm 2 5 in below top of bore and perpendicular to piston pin 3 Piston to bore clearance is difference between bore diameter and piston diameter step 2 minus step 1 KohlerEngines com 71 Reassembly Crankcase Components Oil Seal B closure Plate Style A Sete A gt gene E P eA covemor Gearshan u Coveror Gear Camshaft J Piston Ring Set L Piston Pin Retainer m peon In ee mena Outer Gerotor Gear Oil Drain Plug Governor Cross Shaft Closure Plate Style B T Style B Oil Pump Cover O ring Oil Pump Assembly Ball Style B V opring Style B Style B Style B Oil Pick Up Tube Style B NOTE Make sure engine is assembled using all Check closure plate crankcase cylinder heads and specified torque values tightening sequences valve covers to be certain all old sealing material has and clearances Failure to observe specifications been removed Use gasket remover lacquer thinner or could cause severe engine wear or damage paint remover to remove any remaining traces Clean Always use new gaskets Apply a small amount surfaces with isopropyl alcohol acetone lacquer thinner of oil to threads of critical fasteners before or electrical contact cleaner assembly unless a sealant or Loctite is specified or preapplied Install Flywheel End
101. n you are certain gap is correct torque module mounting screws to 4 0 N m 35 in Ib Repeat these 6 steps to set other ignition module 6 Reattach lead wires to ignition module s noting if resistance is felt indicating a snug fit between male and female terminals If any connections do not feel snug disconnect lead lightly pinch female terminal with a pliers and recheck fit 7 When integrity of all connections has been verified retest for spark 44 KohlerEngines com 24 690 30 Rev D Electrical System Condition Possible Cause Conclusion Strong steady spark is now present Problem should be corrected Go to on both sides Test SAM step 4 Still a spark problem Test SAM Test SAM 1 Trace red power source lead from SAM to harness connection Separate connector and connect red lead of a DC voltmeter to harness terminal Trace ground lead from SAM black on singles green on twins to grounding screw Connect black voltmeter lead to eyelet terminal of ground lead or ground screw bolt Check voltage with key switch in both START and RUN positions A minimum of 7 25 volts must be present a If correct voltage is not measured connect black voltmeter lead directly to negative post of battery and test voltage again in both key positions If correct voltage is now indicated check ground circuit connections If ground screw bolt or any other fasteners in ground circuit are black oxide coated replace them with zinc p
102. nd carefully lift panel from body Unplug connector and pull battery with mounting tape off back of tester Attach connector to new battery and mount battery to case with double backed tape Reinstall faceplate and secure with four screws 24 690 30 Rev D KohlerEngines com 45 Electrical System To test ASAM only using 25 761 21 S tester NOTE SAM must be at room temperature when tested Disconnect all SAM leads isolating it from main wiring harness and ignition module s Testing may be performed with module mounted or loose NOTE Do not allow alligator clip leads to touch each other 1 Connect tester to SAM by attaching a Yellow tester lead to long yellow module lead b Brown tester lead to long brown module lead c Red tester lead to red module lead d Green tester lead to green module lead 2 Check SAM part number stamped on side of housing Verify that you have an analog SAM ASAM Part No 24 584 10 or lower not a digital SAM DSAM Part No 24 584 18 and higher Follow sub step a for testing an ASAM with this tester Digital SAM DSAM modules require Tester 25 761 40 S for proper testing a Depress tester button and hold it down After approximately four seconds a numerical sequence should be displayed beginning with 1 or 2 and continuing to 8 or 9 followed by a letter P pass or F fail Do not release tester button until test cycle completes and display goes off If you get a sign instead of numeri
103. needed Repair or replace any other damaged restricted muffler or exhaust system parts 18 KohlerEngines com 24 690 30 Rev D Troubleshooting COMPRESSION TEST For Command Twins A compression test is best performed on a warm engine Clean any dirt or debris away from base of spark plug s before removing them Be sure choke is off and throttle is wide open during test Compression should be at least 160 psi and should not vary more than 15 between cylinders All other models These engines are equipped with an automatic compression release ACR mechanism It is difficult to obtain an accurate compression reading because of ACR mechanism As an alternative use cylinder leakdown test described below CYLINDER LEAKDOWN TEST A cylinder leakdown test can be a valuable alternative to a compression test By pressurizing combustion chamber from an external air source you can determine if valves or rings are leaking and how badly Cylinder leakdown tester is a relatively simple inexpensive leakdown tester for small engines This tester includes a quick connect for attaching adapter hose and a holding tool 1 Run engine for 3 5 minutes to warm it up 2 Remove spark plug s and air filter from engine 3 Rotate crankshaft until piston of cylinder being tested is at top dead center TDC of compression stroke Hold engine in this position while testing Holding tool supplied with tester can be used if PTO end of crankshaft is acces
104. new adapter gasket and mount air cleaner adapter onto carburetor with screws Torque screws to 4 0 N m 36 in Ib 4 Install a new carburetor gasket onto intake manifold adapter followed by carburetor Install and finger tighten mounting fasteners 5 Connect Z end of throttle linkage and dampening spring to throttle clamp bracket on throttle shaft Attach opposite end of linkage and spring to governor lever 6 Manually move governor lever toward carburetor as far as it will go 7 Check that throttle plate is now fully open or reposition carburetor slightly on mounting hardware so it is fully open Torque mounting screws or nuts to 6 2 7 3 N m 55 65 in Ib Nikki Carburetor NOTE If additional adjustment is required loosen throttle linkage clamp bracket mounting screw set throttle shaft to full throttle position against head of stop screw and retighten clamp mounting screw securely 1 Reinstall rear plug with a new sealing washer Tighten plug securely 2 Reinstall fuel transfer chamber cover with a new gasket Secure with screws KohlerEngines com 25 Fuel System 3 Install new carburetor mounting gasket on manifold studs followed by carburetor and new air cleaner base gasket 4 Reconnect throttle and choke linkages and fuel and vacuum lines 5 Reinstall air cleaner base and breather tube Secure base with mounting nuts Torque nuts to 9 9 N m 88 in Ib Install rest of air cleaner system 6
105. ngine is equipped with SMART SPARK SAM module should be removed from cylinder baffle or blower housing Module will hang loose as part of wiring harness 4 Remove screws securing outer baffles Note location of any lifting strap and position of two short screws one each side on bottom for reassembly KohlerEngines com 59 Disassembly Inspection and Service 5 Remove outer baffles on both sides 3 Remove two remaining screws holding breather 6 Onengines equipped with a metal debris screen cover to crankcase remove screen before removing blower housing 4 Pryunder protruding edge of breather cover with a Plastic debris screens can be removed after blower screwdriver to break RTV or gasket seal Do not pry housing is removed on sealing surfaces as it could cause damage resulting in leaks Most engines use a formed gasket 7 Remove lower blower housing screw and washer rather than RTV sealant securing rectifier regulator ground lead or grounding strap 5 Remove breather cover and gasket if used 8 Remove remaining screws and detach blower 6 Remove breather filter from chamber housing 7 Remove screw breather reed retainer and breather 9 Disconnect plug from key switch in blower housing if reed engine is equipped Remove Intake Manifold Remove Inner Baffles and Breather Cover 5 1 Remove screws securing intake manifold to cylinder Inner valley baffles are attached at one corner using heads Note which screw
106. ning properly e Check if oil level is within operating range on dipstick If it is above sniff for gasoline odor e Check condition of oil Drain oil into a container it should flow freely Check for metal chips and other foreign particles Sludge is a natural by product of combustion a small accumulation is normal Excessive sludge formation could indicate over rich fuel settings weak ignition overextended oil change interval or wrong weight or type of oil was used CLEANING ENGINE Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent After inspecting external condition of engine clean engine thoroughly before disassembly Clean individual components as engine is disassembled Only clean parts can be accurately inspected and gauged for wear or damage There are many commercially available cleaners that will quickly remove grease oil and grime from engine parts When such a cleaner is used follow manufacturer s instructions and safety precautions carefully Make sure all traces of cleaner are removed before engine is reassembled and placed into operation Even small amounts of these cleaners can quickly break down lubricating properties of engine oil KohlerEngines co
107. ol to remove ridge 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 procedures for other connecting rod and piston assembly Piston and Rings Piston and Rings Components and Details Piston Oil Control Ring 3 Piece Expander C Middle Compression Ring 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 24 690 30 Rev D Disassembly Inspection and Service Normally very little wear takes place in piston 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 p
108. om 24 690 30 Rev D Governor Gear Assembly Governor Shaft Component and Details Gear Shaft 19 40 mm 0 7638 in 34 0 mm 1 3386 in 33 5 mm 1 3189 in Governor gear assembly is located inside closure plate If service is required refer to Inspection Disassembly and Reassembly procedures Oil Pump Assembly Style A A Oil Pump Original Style A 24 690 30 Rev D Later Style A C Oil Pickup Tube me el Ong One Piece Relief J Torque Sequence Valve Style A Disassembly Inspection and Service 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 closure plate 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 it only if it is damaged After removing damaged shaft press or lightly tap replacement shaft into closure plate to depth shown Reassembly 1 Install locking tab thrust washer on governor gear shaft with tab down 2 Position regulating pin within governo
109. on tool Make sure identification mark is up or dye colored stripe if contained is to left of end gap 3 Top compression ring top groove Install top ring using a piston ring expender Make sure identification mark is up or dye colored stripe if contained left of end gap Install New Piston Rings Piston Ring Orientation A Top Oil Ring Rail Bottom Oil Ring Rail Gap Gap C Intermediate Ring Oil Ring Expander Gap Gap E Top Ring Gap F 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 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 68 KohlerEngines com 24 690 30 Rev D Connecting Rods Offset stepped cap connecting rods are used in all these engines Inspection and Service Check bearing area
110. ondary area As negative pressure vacuum is created at carburetor venturi and is transmitted through dry gas hose to chamber secondary diaphragm is drawn down and contacts secondary lever Fuel will flow in proportion to air velocity through carburetor venturi ensuring an ideal mixture at all engine speeds Whenever engine is operating vacuum diaphragm is down against floor and spring is compressed Idle and starting adjustment is made with a tamper resistant screw which regulates whisker wire system opening up secondary orifice slightly but only when vacuum diaphragm is drawn down Very little vacuum is needed to start this vacuum diaphragm travel 0 2 in Mercury to start and 0 5 in Mercury for full travel When engine stops rotating loss of vacuum in section releases diaphragm causing bumper to push against secondary lever overcoming action of whisker wire and ensuring 100 lock off This patented Beam design will lock off primary pressures up to five times in excess of normal and permits starting without priming or choking Nikki Regulator Primary Chamber Details and Components Primary Valve Primary Valve Seat Primary Chamber Primary Diaphragm Primary Diaphragm Spring Adjustment Lu Contact Button G Primary Valve Lever Primary Lever Spring Primary Pressure Fuel Inlet To Secondary Chamber 28 KohlerEngines com Primary chamber reduces high pressure fuel flow from tank and vaporizer down to ap
111. ondition of part 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 then 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 A flashing LOW light can Rectifier regulator is faulty and should not be used also occur as a result of an inadequate ground lead connection Make certain connection location is clean and clamp is secure Other lights come on 24 690 30 Rev D KohlerEngines com 47 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 To test charging system for battery continuously chargin
112. operating and fuel is being drawn from secondary chamber secondary diaphragm is raised by atmospheric pressure simultaneously lifting secondary valve lever opening secondary valve allowing fuel to flow When engine is running at idle there may not be enough vacuum created in carburetor venturi to overcome tension of secondary diaphragm spring and secondary diaphragm cannot open valve Under those conditions idle adjusting screw and balance spring are used to apply just enough pressure on diaphragm to maintain sufficient fuel flow for idle operation 24 690 30 Rev D Vacuum lock off mechanism is located in secondary chamber When engine is running manifold vacuum above diaphragm draws it up so secondary valve can function normally When engine is stopped manifold vacuum is terminated and diaphragm relaxes and pushes down on secondary valve lever preventing any fuel flow or leakage through regulator Preventative Maintenance Regulator is preset at factory and generally requires no further adjustment No periodic service is required Over time depending on fuel quality operating environment and system performance fuel deposits can accumulate inside regulator For Nikki regulators perform following steps to remove any accumulated deposits 1 Turn supply valve off run engine out of fuel and turn off ignition switch 2 Disconnect and ground spark plug leads 3 Remove 1 8 in pipe plug from bottom of regulator
113. or are out of running clearance specifications If crankshaft turns easily and noiselessly and there is no evidence of scoring grooving etc on races or bearing surfaces bearings can be reused Inspect crankshaft keyways If they are 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 and Tolerances 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 one size under When grinding a 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 Drill a 3 16 in hole through plug in crankshaft 2 Thread a 3 4 in or 1 in 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
114. or spring from main control bracket to appropriate hole in governor lever as indicated in applicable chart Note that hole positions are counted from pivot point of governor lever 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 Nm 40 in Ib 2 Connect wire lead green to Oil Sentry terminal 24 690 30 Rev D Reassembly Governor Lever Hole Position 6 mm 6 mm Governor Lever and Hole Position RPM Chart Governor High Idle RPM Gov Lever spring Color Hole No Code Clear 3801 4000 5 3601 3800 A Clear 3451 3600 3301 3450 2 Clear 3101 3300 4 Purple 2951 3100 3 Purple 2800 2950 2 Purpe 3750 3150 3 Purpe 5 Regulation others 10 E Hoe3 G HoleS Governor Lever Hole Position 8 mm 8 mm Governor Lever and Hole Position RPM Chart Governor High Idle RPM Gov Lever Spring Color Hole No Code 3900 4000 4 Red 385 3 Orange 3750 3800 3 Purple 36003700 3 Black 35003550 3 Red 34003450 2 Purple 33003350 2 Bu 3200 3250 1 Orange 3180 3 Black 300 2 Cla 300 1 Red 290 31 Cla 324 2 Orange 3120 1 Cla 5 Regulation others 10 A Govemorlever B Holei
115. proximately 29 kPa 4 psi Fuel flowing from vaporizer enters inlet of regulator under approximately 76 kPa 11 psi of pressure There it is delivered to primary chamber through clearance between primary valve and valve seat As fuel continues to flow and primary chamber approaches 29 kPa 4 psi primary diaphragm overcomes tension of diaphragm spring As diaphragm and contact button move up primary lever spring pushes primary lever up in turn closing primary valve and stopping flow of fuel As fuel is consumed and pressure in primary chamber drops below 29 kPa 4 psi diaphragm spring tension will be greater than fuel pressure causing primary diaphragm to be pushed down This causes contact button to push primary lever down in turn opening primary valve and admitting more fuel In this manner pressure within primary chamber is maintained at a relatively constant 29 kPa 4 psi Secondary Chamber Details and Components D Secondary Valve B Secondary Valve Seat Secondary C Secondary Chamber D Diaphragm Secondary Secondary Valve Diaphragm Spring Lever Vacuum Lock off KS Diaphragm ER Idle Adjust Screw Balance Spring ica K To Intake Manifold To Carburetor Secondary chamber further reduces fuel pressure from 29 kPa 4 psi of primary chamber to near 0 kPa 0 psi pressure to prevent excessive fuel flow to carburetor Fuel enters secondary chamber through clearance between secondary valve and valve seat While engine is
116. r Digital Design zo Inc For checking operating speed RPM of an engine Offset Wrench K and M Series B gt 04 S For removing and reinstalling ide barrel retaining nuts Oil Pressure Test Kit Kohler 25 761 06 S For testing verifying oil pressure on pressure lubricated engines Rectifier Regulator Tester 120 volt current Kohler 25 761 20 S Rectifier Regulator Tester 240 volt current Kohler 25 761 41 S For testing rectifier regulators Components of 25 761 20 S and 25 761 41 S Design Technology Inc CS PRO Regulator Test Harness DTI 031 Special Regulator Test Harness with Diode DTI 033 Spark Advance Module SAM Tester Kohler 25 761 40 S For testing SAM ASAM and DSAM on engines with SMART SPARK Starter Servicing Kit All Starters SE Tools KLR 82411 For removing and reinstalling drive retaining rings and brushes Individual component available Starter Brush Holding Tool Solenoid Shift SE Tools KLR 82416 Triad OHC Timing Tool Set Kohler 28 761 01 S For holding cam gears and crankshaft in timed position while installing timing belt Valve Guide Reamer K and M Series Design Technology Inc For properly sizing valve guides after installation DTI K828 Valve Guide Reamer O S Command Series Kohler 25 455 12 S For reaming worn valve guides to accept replacement oversize valves Can be used in low speed drill press or with handle below for hand reaming Reamer Handle Design Technology Inc For hand reaming using Kohler
117. r gear flyweight assembly and slide both onto governor shaft Plastic Oil Pickup KohlerEngines com 65 Disassembly Inspection and Service Oil Pump Assembly Style A Oil pump is mounted inside closure plate If service is required continue with Disassembly Inspection and Reassembly Disassembly 1 Remove screws 2 Remove oil pump assembly from closure plate 3 Remove oil pump rotor 4 Remove oil pickup by unhooking locking clip and pulling it free from oil pump body 5 If relief valve is similar to shown drive out pin to remove oil pressure relief valve piston and spring Refer to following inspection and reassembly procedures If relief valve is a one piece style staked to oil pump housing removal should not be attempted nor is internal servicing possible If a problem with relief valve is encountered oil pump should be replaced Inspection Inspect oil pump housing gear and rotors for nicks burrs wear or any visible damage If any parts are worn or damaged replace oil pump Inspect oil pressure relief valve piston It should be free of nicks or burrs Check spring for wear or distortion Free length of spring should be approximately 47 4 mm 1 8 in Replace spring if it is distorted or worn Reassembly 1 Install pressure relief valve piston and spring 2 Install oil pickup to oil pump body Lubricate O ring with oil and make sure it remains in groove as pickup is being install
118. re available in STD bore size and in 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize Replacement pistons include new piston ring sets and new piston pins Replacement ring sets are also available separately for STD 0 25 mm 0 010 in and 0 50 mm 0 020 in oversize pistons 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 deglazed before service ring sets are used 2 If cylinder bore does not need reboring 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 two rings each in turn in its running area in cylinder bore and check end gap Compare ring gap to tolerances listed in Specifications 5 After installing new compression top and middle rings on piston check piston to ring side clearance Compare clearance to tolerance listed in Specifications If side clearance is greater than specified a new piston must be used KohlerEngines com 67 Disassembly Inspection and Service 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 installati
119. revent 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 a Press in cap reinsert dipstick into tube press completely down Or b Thread on cap reinsert dipstick into tube rest cap on tube do not thread cap onto tube 2 Remove dipstick check oil level Level should be at top of indicator on dipstick 3 If oil is low on indicator add oil up to top of indicator mark 32 KohlerEngines com 4 Reinstall dipstick and tighten securely 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 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 minute
120. rmature be careful 9 not to lose thrust washer Disconnect lead wire from solenoid Remove nuts securing solenoid and remove solenoid from starter assembly Remove thru bolts Remove commutator end cap Remove insulator and brush springs from brush spring holder Remove armature from frame Remove drive lever and armature from drive end cap Stop collar consists of two similar pieces held in place by being snapped over a retainer Retainer is held in place by a groove in armature shaft To remove stop collar two pieces must be pried off retainer When stop collars are removed retainer can be removed from armature shaft Do not reuse retainer Brush Replacement Brushes in starter are part of starter frame Brush kit contains four replacement brushes and springs If replacement is necessary all four brushes should be replaced Remove brushes from brush holder and remove brush holder from frame Cut brush lead wire at edge of post with a pair of nippers File off any burrs on post Replacement brushes have a solid portion which should be crimped on post Solder crimped portion to post Replace brush holder in frame and place brushes in brush holder Reinstall springs Starter Reassembly NOTE Always use a new retainer Tighten retainer in gt groove to secure Insert rear stop collar on armature shaft Place retainer in groove on armature shaft Fit front stop collar over shaft and bring front
121. rter connect leads to solenoid KohlerEngines com 81 Reassembly Install Carburetor Explosive Fuel can cause fires and severe burns If a gaseous odor is detected ventilate area and contact an authorized service technician LPG is extremely flammable and is heavier than air and tends to settle in low areas where a spark or flame could ignite gas Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area NG is extremely flammable is lighter than air and rises Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in area To ensure personal safety installation and repair of LPG NG fuel supply systems must be performed only by qualified LPG NG system technicians Improperly installed and maintained LPG NG equipment could cause fuel supply system or other components to malfunction causing gas leaks Observe federal state and local laws governing LPG NG fuel storage and systems 1 Install a new carburetor gasket Make sure all holes align and are open 2 Install carburetor throttle linkage and governor lever as an assembly If a plastic intake manifold is used attach ground lead to carburetor mounting screw 3 Torque carburetor mounting screws or nuts to 6 2 7 3 N m 55 65 in Ib Install LPG NG Components 1 Install regulator bracket to crankcas
122. s are present A WARNING Hot Parts can cause zh severe burns KA Do not touch engine while operating or just after stopping Never operate engine with heat shields or guards removed KohlerEngines com Cleaning Solvents can cause severe injury or death Use only in well ventilated areas away from ignition sources Carburetor cleaners and solvents are extremely flammable Follow cleaner manufacturer s warnings and instructions on its proper and safe use Never use gasoline as a cleaning agent Electrical Shock can cause injury Do not touch wires while engine is running Damaging Crankshaft and Flywheel can cause personal injury Using improper procedures can lead to broken fragments Broken fragments could be thrown from engine Always observe and use precautions and procedures when installing flywheel Failure to utilize or reassemble debris screen as designed could result in debris screen failure and serious personal injury 24 690 30 Rev D Maintenance MAINTENANCE INSTRUCTIONS Before working on engine or equipment disable engine as WARNING follows 1 Disconnect spark plug lead s 2 Disconnect Accidental Starts can cause severe injury or Negative battery cable from battery death Before disconnecting negative ground cable make Disconnect and ground spark plug lead s sure all switches are OFF If ON a spark will occur at before servicing ground cable terminal
123. s 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 Blower Housing Mounted Oil Cooler 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 Crankcase Mounted Oil Cooler Clean fins with a brush or compressed air 24 690 30 Rev D 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 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 5927 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
124. s hold wiring clamps same fasteners as breather cover 2 Remove intake manifold and intake manifold gaskets 1 Remove screws securing inner baffles aluminum intake manifolds or O rings plastic intake manifolds 3 Leave wiring harness attached to manifold 2 Remove both inner baffles Cylinder Head Components Spark Plug B D El ca EO Valve Stem Seal G Hydraulic Lifter H Retainer d Valve Spring Valve Spring Retainer K Push Rod Valve Keeper M RokeAm N Rocker Arm Pivot O Valve Cover O ring P Valve Cover Remove Valve Covers 1 Remove screws securing each valve cover Note M eee position of any attached brackets or lifting straps Three valve cover designs have been used Earliest type used a gasket and RTV sealant between cover and 2 nn bs lifting nn sealing surface of cylinder head Second type had a nich side nn aie rn Je pepe INDIE black O ring installed in a groove on underside of cover k and may have metal spacers in bolt holes Latest design uses a brown O ring and bolt holes spacers are molded in place 60 KohlerEngines com 24 690 30 Rev D Remove Spark Plugs Remove spark plug from each cylinder head Remove Cylinder Heads and Hydraulic Lifters NOTE 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 Exhaust lifters are
125. sembly White AC on Rectifier Regulator Oil Sentry Pulse Alternate a B men R E Signal ka Pulse Signal Fuse V Starter Solenoid Tang W Starter Solenoid Stud X Blue Ui HEN m Re wee ao sensus A cama far PBN CREE SINN A osem um mem LIC RN m see as emer a mem an Car 24 690 30 Rev D KohlerEngines com 41 Electrical System Wiring Diagram 3 Amp Unregulated Battery Charging System 70 Watt Lighting AY gt Optional Oil Optional Oil A Sentry Switch 12 V Battery Sentry Switch Light Toad White Shutdown Indicator Light Fes o mum re om K Bue L Solenoid M Ligts N Starter O Yellow 3 Amp 70 Watt rene a armer TR O KADET 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 have 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
126. sh 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 longblock assembly and overall proper operation 24 690 30 Rev D Install Spark Plugs 1 2 3 Check gap using wire feeler gauge Adjust gap to 0 76 mm 0 03 in for all except NG with CD fixed timing or 0 51 mm 0 02 in for NG with CD fixed timing Install plug into cylinder head Torque plug to 27 N m 20 ft Ib Install Ignition Modules 1 2 N 24 690 30 Rev D Rotate flywheel to position magnet away from ignition module bosses On engines equipped with SMART SPARK both modules are installed with tabs out On engines not equipped with SMART SPARK 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 Install each ignition module to crankcase bosses with screws hex flange or allen head based on model Slide modules up as far away from flywheel as possible and snug screws to hold them in position Rotate flywheel to position magnet directly under one ignition module Insert a 0 30 mm 0 0
127. sible Lock holding tool onto crankshaft Install a 3 8 in breaker bar into hole slot of holding tool so it is perpendicular to both holding tool and crankshaft PTO If flywheel end is more accessible use a breaker bar and socket on flywheel nut screw to hold it in position An assistant may be needed to hold breaker bar during testing If engine is mounted in a piece of equipment it may be possible to hold it by clamping or wedging a driven component Just be certain that engine cannot rotate off of TDC in either direction Install adapter into spark plug hole but do not attach it to tester at this time Turn regulator knob completely counterclockwise Connect an air source of at least 50 psi to tester Turn regulator knob clockwise increase direction until gauge needle is in yellow set area at low end of scale Connect tester quick connect to adapter hose While firmly holding engine at TDC gradually open tester valve Note gauge reading and listen for escaping air at combustion air intake exhaust outlet and crankcase breather 0 N u Condition Conclusion Gauge reading in low green zone Gauge reading in moderate yellow zone Engine is still usable but there is some wear present Customer should start planning for overhaul or replacement Gauge reading in high red zone Rings and or cylinder have considerable wear Engine should be reconditioned or replaced 24 690 30 Rev D KohlerEngines com 19 Air Cleaner Int
128. sses of flywheel Install fan onto flywheel using four screws Torque screws to 9 9 N m 88 in Ib 76 KohlerEngines com 24 690 30 Rev D Install Plastic Debris Screen Failure to utilize or reassemble debris screen as designed could result in debris screen failure and serious personal injury If engine has a plastic debris screen snap screen onto fan Due to possibility of damaging posts during removal install retainers on different posts from which they were removed Start retainers by hand then push them down with a 13 mm 1 2 in socket until they lock If engine has a metal screen it will be installed later Cylinder Head Components ae Install Hydraulic Lifters NOTE Hydraulic lifters should always be installed in same position as before disassembly Exhaust lifters are located on output shaft 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 lifter preparation bleed down procedures 2 Apply camshaft lubricant to bottom surface of each lifter Lubricate hydraulic lifters and lifter bores in crankcase with engine oil 24 690 30 Rev D E re Cap F Vave Stem Seal 1 Valve Spring J Valve Spring Retainer m Reassembly Install Supports for Metal Debris Screen 1 Ifa metal debris screen is used with threaded individual supports install a spa
129. stator 24 690 30 Rev D KohlerEngines com 49 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 inertia drive or 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 or 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 re
130. stopper at 0 line Make sure pinch clamp is closed l l 3 Run engine and observe gauge reading 2 Start engine and run no load high speed l 3 0 dro terlevel incu Analog tester needle movement to left of O is a Mid dic EVEN vacuum and movement to right indicates a pressure Level in engine side should be a minimum of Digital tester depress test button on top of tester 10 2 cm 4 in above level in open side a If B m Crankcase vacuum should be a minimum of 10 2 cm EL 4 in of water If reading is below specification or if a u nn an m pressure is present check table below for possible p p i causes and conclusions below 4 Close pinch clamp before stopping engine Condition Conclusion Crankcase breather clogged or inoperative NOTE If breather is integral part of valve cover and cannot be serviced separately replace valve cover and recheck pressure Disassemble breather clean parts thoroughly check sealing surfaces for flatness reassemble and recheck pressure Seals and or gaskets leaking Loose or improperly torque Replace all worn or damaged seals and gaskets Make fasteners sure all fasteners are tightened securely Use appropriate torque valves and sequences when necessary Piston blow by or leaky valves confirm by inspecting Recondition piston rings cylinder bore valves and components valves guides Restricted exhaust Check exhaust screen spark arrestor if equipped Clean or replace as
131. straight shank type bolts are used torque in increments to 22 7 N m 200 in Ib If 8 mm step down bolts are used torque in increments to 14 7 N m 130 in Ib If 6 mm straight shank bolts are used torque in increments to 11 3 N m 100 in Ib Illustrated instructions are provided in service rod package Repeat above procedure for other connecting rod and piston assembly Install Camshaft Liberally apply camshaft lubricant to each cam lobe Lubricate camshaft bearing surfaces of crankcase and camshaft with engine oil Position timing mark of crankshaft gear at 12 o clock position Turn governor cross shaft clockwise until lower end of shaft contacts cylinder Make sure cross shaft remains in this position while installing camshaft 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 KohlerEngines com 73 Reassembly Determining Camshaft End Play 1 Install shim removed during disassembly onto camshaft 2 Position camshaft end play checking tool on camshaft 3 Apply pressure on camshaft end play checking tool pushing camshaft toward crankshaft Use a feeler gauge to measure camshaft end play between shim spacer and checking tool Camshaft end play should be 0 076 0 127 mm 0 003 0 005 in 4 f camshaft end play is not within specified range remove checking
132. t apply a 1 5 mm 1 16 in bead to sealing surface of both cylinder heads install a new cover gasket on each then apply a second bead of sealant on top surface of gaskets For O ring type covers install a new O ring in groove of each cover Do not use gaskets or RTV sealant 84 KohlerEngines com 4 Locate cover with oil fill neck on same side as removed and install lifting strap in original position With O ring type covers position cover on cylinder head If loose spacers were used insert a spacer in each screw hole On both types install four screws in each cover and finger tighten 5 Torque valve cover fasteners to proper specification using sequence shown Torque Specifications Covers Gasket RTV 3 4 N m 30 in Ib Black O ring w shoulder screws N m 50 in Ib 5 6 w screws and spacers 9 9 N m 88 in Ib Yellow or Brown O ring w integral spacers 6 2 N m 55 in Ib Install Air Cleaner Assembly NOTE Route fuel line in contour to avoid restriction 1 Attach rubber breather hose to breather cover Connect fuel inlet line to carburetor and secure with a clamp 2 Position a new gasket and air cleaner base while carefully pulling loose end of rubber breather hose through base until properly seated collars sealed against each side of base 3 Secure air cleaner base and bracket using screws Position bracket with hole toward breather hose Be careful not to drop screws into carburetor If a rear
133. t as follows 1 Make sure throttle linkage is connected to governor arm and throttle lever on carburetor 2 Loosen nut holding governor lever to cross shaft 3 Move governor lever toward carburetor as far as it will go wide open throttle and hold in this position 24 690 30 Rev D 4 Insert a long thin rod or tool into hole on cross shaft and rotate shaft clockwise 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 and adjust as follows 1 Toincrease sensitivity move spring closer to governor cross shaft 2 To decrease sensitivity move spring away from governor cross shaft ELECTRONIC GOVERNOR Electronic governor regulates engine speed at varying loads Typical electronic governor includes e Digital linear actuator e Throttle linkage e Linkage spring e Choke linkage e hrottle lever adapter e Governor Control Unit Digital Linear Actuator DLA Energizing bi directional digital linear actuator coils in proper sequence causes threaded shaft to move out of or back into rotor in precise linear increments When power is removed actuator shaft remains in position
134. t bearing with heavy grease and stick bearing into race Wipe some grease on face of thrust washer and stick it onto thrust bearing Wipe some grease on face of original shim spacer and stick it onto thrust washer Install closure plate onto crankcase without applying RTV sealant and secure it with only two or three fasteners at this time Use a dial indicator to check crankshaft end play End play should be 0 070 1 190 mm 0 0028 0 0468 in except for CH25 engines below Serial No 2403500008 end play should be 0 050 0 75 mm 0 0020 0 0295 in Shim spacers are available in three color coded thicknesses listed below if adjustment is needed Crankshaft End Play Shims Green 0 8366 0 9127 mm 0 8750 mm 0 034 in Nominal Yellow 1 0652 1 1414 mm 1 1033 mm 0 043 in Nominal Red 1 2938 1 3700 mm 1 3319 mm 0 052 in Nominal N o 24 690 30 Rev D Remove closure plate If end play requires adjustment remove original spacer and install appropriate size shim spacer in its place Then follow procedure under Install Closure Plate Assembly Install Closure Plate Oil Seal Oil Seal Depth Seal Depth 8 0 mm 0 314 in Check to make sure there are no nicks or burrs in crankshaft bore of closure plate 2 Apply a light coat of engine oil to outside diameter of oil seal 3 Drive oil seal into closure plate using a seal driver Make sure oil seal is installed straight and true in bore to depth shown 24 690
135. tion test continuity Repeat test several times and check for continuity Ohmmeter should indicate continuity Repeat test several times Condition Conclusion Solenoid fails to activate No continuity is indicated Plunger fails to stay retracted o6 KohlerEngines com 24 690 30 Rev D Disassembly Inspection and Service A WARNING Before working on engine or equipment disable engine as follows 1 Disconnect spark plug lead s 2 Disconnect Accidental Starts can cause severe injury or negative battery cable from battery death Before disconnecting negative ground cable make sure Disconnect and ground spark plug lead s all switches are OFF If ON a spark will occur at ground cable terminal which could cause an explosion if hydrogen En gas or LPG NG fuel vapors are present External Engine Components e a 3 cc D Carburetor Plastic Intake Manifold H Outer Baffle Breather Gasket Breather Cover TA Vaporizer B lokofi te C Regulator E Gasket F Intake Manifold G 1 mner Batre J Breather Reed K LM Breather Tuve N OlSemy 0 Fir P AirCleaner ral oie R Nipple S OlCode T Electric Starter u w Lifting Bracket Fixed Guard Blower Housing Debris Shield 24 690 30 Rev D KohlerEngines com 5 N Disassembly Inspection and Service Clean all parts thoroughly as engine is disassembled Only clean parts can be accurate
136. tuds 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 69 mm 2 3 4 in c Remove nuts and repeat procedure as required 4 Install cylinder head Match numbers on cylinder heads and crankcase Make sure head is flat on gasket and dowel pins 5 Lightly lubricate exposed upper threads of studs with engine oil Install a flat washer and nut onto each mounting stud Torque nuts in two stages first to 16 9 N m 150 in Ib finally to 35 5 N m 315 in Ib following sequence shown Install Push Rods and Rocker Arms NOTE Push rods should always be installed in same position as before disassembly Early models used hollow push rods with special rocker arms They are not interchangeable with later current style solid push rods and associated rocker arms Do not mix these A replacement kit is available with solid components 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 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 two screws 3 Torque screws to 18 1 N m 160 in Ib Repeat for other rocker arm 4 Use a spanner wrench or rocker arm lifting tool to lift rocker arms and position pu
137. 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 a warped head excessive corrosion or a 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 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 62 KohlerEngines com 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
138. vicing Starter reassembly when not replacing brushes brush holder assembly a Carefully unhook retaining caps from brush assemblies Do not lose springs 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 Install end cap onto armature and frame aligning thin raised rib in end cap with corresponding slot in grommet of positive brush lead 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 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 Connect positive brush lead bracket to solenoid and secure with nut Torque nut to 8 11 N m 71 97 in Ib Do not
139. voltmeter shorts in wiring harness Condition Conclusion Voltage is less than 15 Test stator using an Voltage is 28 volts or otator winding is OK 2 CANEL more Voltage is less than 28 Test stator using an 3 With engine stopped measure resistance of stator volts ohmmeter from lighting lead to ground using an ohmmeter aed edi Condition Conclusion ith charging lead disconnected from battery an engine stopped measure resistance from charging A a ee Stator is OK lead to ground using an ohmmeter Note reading Dp Dam Reverse leads and measure resistance again Resistance is 0 ohms iind is shorted Replace stator In one direction resistance should be infinity ohms open circuit With leads reversed some resistance Resistance is infinity Stator or lighting lead is should be measured about midscale on Rx1 range ohms open Replace stator Condition Conclusion Resistance is low in both Diode is shorted Replace directions diode Resistance is high in both Diode or stator winding is directions open Continue testing 4 Cutsleeving on charging lead to expose diode connections Measure resistance from stator side of diode to ground using an ohmmeter Condition Conclusion Resistance is otator winding is OK approximately 1 07 ohms diode is open Replace diode Resistance is 0 ohms Stator winding is shorted Replace stator Resistance is infinity Stator winding or lead is ohms open Replace
140. which could cause an explosion if hydrogen gas or LPG NG fuel vapors are present Normal maintenance replacement or repair of emission control devices and systems may be performed by any repair establishment or individual however warranty repairs must be performed by a Kohler authorized dealer MAINTENANCE SCHEDULE Every 25 Hours e Service precleaner element Air Cleaner Intake Every 100 Hours Every 200 Hours e Change oil filter Lubrication System Every 500 Hours or Annually e Check all lines high pressure vacuum including fittings for leaks Fuel System e Drain regulator of accumulated fuel deposits Fuel System e Replace spark plugs and set gap Electrical System Every 500 Hours or Annually e Have lock off filter serviced Fuel System e Have combustion deposits removed if using non synthetic oil Every 1500 Hours e Have regulator disassembled cleaned and reset Fuel System e Have vaporizer disassembled cleaned and serviced Fuel System Perform these procedures more frequently under severe dusty dirty conditions Must be performed by a Kohler authorized dealer or qualified LPG personnel only REPAIRS SERVICE PARTS Kohler genuine service parts can be purchased from Kohler authorized dealers To find a local Kohler authorized dealer visit KohlerEngines com or call 1 800 544 2444 U S and Canada 24 690 30 Rev D KohlerEngines com 9 Maintenance OIL RECOMMENDATIONS oynt
141. y Gree SpakPug 0 KN oe qr mene o mania w Sets Ur ee ERE s nn 0 piano r PIERII DE jo hn Oil Sentry Panel ME Solenoid Lead prem Intake Manifold Screw rRNA as Light Remote Light UAE al hens Ta Ren E N U E AK Key Switch Ground AL Rectifier AM Blue Red AN Battery Positive AS Starter Solenoid Tang AT Black Ground 24 690 30 Rev D KohlerEngines com 39 Electrical System Wiring Diagram 15 20 25 Amp Regulated Battery Charging System with DSAI Ignition and Key Switch 40 KohlerEngines com 24 690 30 Rev D Electrical System Digital Spark Advance Ignition DSAl System This system uses a digital microprocessor which is located in ignition modules Ignition timing varies depending upon engine speed with this system There are 2 inductive style ignition modules that control ignition timing based on engine RPM A typical DSAI application consists of e magnet assembly which is permanently affixed to flywheel e 2 inductive 12 volt ignition modules which mount on engine crankcase e 1 12 volt battery which supplies current to ignition modules e 1 kill switch or key switch which grounds spark advance module to stop engine e 2 spark plugs Black Ground Intake Oil Pressure Switch Green Sa Sentry C Manifold Mounting Black Pulse Wr Lead SCION Wie opark Plug s H Black Ground Flywheel Stator i omes a TE iiid utc DS ee ES As

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