Kohler XT-6, XT6.5, XT650, XT6.75, XT-7 Service Manual

...

XT-6, XTR-6, XT6.5, XT650, XT6.75, XT675, XT-7, XTR-7, XT775, XT8 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 Specications 10 Tools and Aids 13 Troubleshooting 17 Air Cleaner/Intake 18 Fuel System 24 Governor System 26 Lubrication System 27 Electrical System 31 Starter System 33 Disassembly/Inspection and Service 45 Reassembly

114 690 01 Rev. G KohlerEngines.com

Safety

SAFETY PRECAUTIONS

WARNING: A hazard that could result in death, serious injury, or substantial property damage.

CAUTION: A hazard that could result in minor personal injury or property damage.

NOTE: is used to notify people of important installation, operation, or maintenance information.

WARNING

Explosive Fuel can cause res and severe burns.

Do not ll fuel tank while engine is hot or running.

Gasoline is extremely ammable and its vapors can explode if ignited. Store gasoline only in approved containers, in well ventilated, unoccupied buildings, away from sparks or ames. Spilled fuel could ignite if it comes in contact with hot parts or sparks from ignition. Never use gasoline as a cleaning agent.

WARNING

Rotating Parts can cause severe injury.

Stay away while engine is in operation.

Keep hands, feet, hair, and clothing away from all moving parts to prevent injury. Never operate engine with covers, shrouds, or guards removed.

WARNING

Carbon Monoxide can cause severe nausea, fainting or death.

Avoid inhaling exhaust fumes.

Engine exhaust gases contain poisonous carbon monoxide. Carbon monoxide is odorless, colorless, and can cause death if inhaled.

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.

Hot Parts can cause severe burns.

Do not touch engine while operating or just after stopping.

Never operate engine with heat shields or guards removed.

Cleaning Solvents can cause severe injury or death.

Use only in well ventilated areas away from ignition sources.

Carburetor cleaners and solvents are extremely ammable. Follow cleaner manufacturer’s warnings and instructions on its proper and safe use. Never use gasoline as a cleaning agent.

WARNING

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 ywheel.

Uncoiling Spring can cause severe injury.

Wear safety goggles or face protection when servicing retractable starter.

Retractable starters contain a powerful, recoil spring that is under tension. Always wear safety goggles when servicing retractable starters and carefully follow instructions in Retractable Starter for relieving spring tension.

CAUTION

WARNING

KohlerEngines.com 14 690 01 Rev. G

Maintenance

MAINTENANCE INSTRUCTIONS

WARNING

Accidental Starts can cause severe injury or death.

Disconnect and ground spark plug lead(s) before servicing.

Normal maintenance, replacement or repair of emission control devices and systems may be performed by any repair establishment or individual; however, warranty repairs must be performed by a Kohler authorized dealer.

MAINTENANCE SCHEDULE

After rst 3-5 Hours

● Change oil. Lubrication System

Every 25 Hours or Annually¹

● Service/replace precleaner. Air Cleaner/Intake

● Check air cleaner for dirty, loose or damaged parts. Air Cleaner/Intake

Every 50 Hours or Annually

● Change oil. Lubrication System

● Replace fuel lter (if equipped).

Before working on engine or equipment, disable engine as follows: 1) Disconnect spark plug lead(s). 2) Disconnect negative (–) battery cable from battery.

Every 50 Hours or Annually¹

● Replace air cleaner element. Air Cleaner/Intake

Every 100 Hours or Annually¹

● Clean spark arrestor (if equipped).

Every 100 Hours or Annually²

● Have combustion chamber decarbonized.

Every 125 Hours or Annually¹

● Replace spark plug and set gap. Electrical System

Perform these procedures more frequently under severe, dusty, dirty conditions.

Have a Kohler authorized dealer perform this service.

REPAIRS/SERVICE PARTS

Kohler genuine service parts can be purchased from Kohler authorized dealers. To nd a local Kohler authorized dealer visit KohlerEngines.com or call 1-800-544-2444 (U.S. and Canada).

14 690 01 Rev. G KohlerEngines.com

Maintenance

OIL RECOMMENDATIONS

We recommend use of Kohler oils for best performance. Other high-quality detergent oils (including synthetic) of API (American Petroleum Institute) service class SJ or higher are acceptable. Select viscosity based on air temperature at time of operation as shown in table below.

FUEL RECOMMENDATIONS

WARNING

Explosive Fuel can cause res and severe burns.

Do not ll fuel tank while engine is hot or running.

STORAGE

If engine will be out of service for 2 months or more follow procedure below.

1. Add Kohler PRO Series fuel treatment or equivalent to fuel tank. Run engine 2-3 minutes to get stabilized fuel into fuel system (failures due to untreated fuel are not warrantable).

2. Change oil while engine is still warm from operation. Remove spark plug(s) and pour about 1 oz. of engine oil into cylinder(s). Replace spark plug(s) and crank engine slowly to distribute oil.

3. Disconnect negative (-) battery cable.

4. Store engine in a clean, dry place.

NOTE: E15, E20 and E85 are NOT approved and

should NOT be used; effects of old, stale or contaminated fuel are not warrantable.

Fuel must meet these requirements:

● Clean, fresh, unleaded gasoline.

● Octane rating of 87 (R+M)/2 or higher.

● Research Octane Number (RON) 90 octane minimum.

● Gasoline up to 10% ethyl alcohol, 90% unleaded is acceptable.

● Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline blend (max 15% MTBE by volume) are approved.

● Do not add oil to gasoline.

● Do not overll fuel tank.

● Do not use gasoline older than 30 days.

KohlerEngines.com 14 690 01 Rev. G

Specications

ENGINE IDENTIFICATION NUMBERS

Kohler engine identication numbers (model, specication and serial) should be referenced for efcient repair, ordering correct parts, and engine replacement.

Model .....................XT-6

Courage Engine

Vertical Shaft

Numerical Designation

Specication ...............XT149-0001

Serial .....................4223500328

Year Manufactured Code Factory Code

Code Year 42 2012 43 2013 44 2014

GENERAL SPECIFICATIONS

3,6

XT-6, XTR-6

XT6.5, XT650,

XT6.75, XT675

XT-7, XTR-7,

XT775, XT8

Bore 65 mm (2.6 in.) 70 mm (2.8 in.) Stroke 45 mm (1.8 in.) Displacement 149 cc (9.1 cu. in.) 173 cc (10.6 cu. in.) Oil Capacity (rell) 0.6 L (20 oz.) Maximum Angle of Operation (@ full oil level)

TORQUE SPECIFICATIONS

3,5

XT-6, XTR-6

XT6.5, XT650,

XT6.75, XT675

20°

XT-7, XTR-7,

XT775, XT8

Air Cleaner Base

Stud Fastener 8 N·m (71 in. lb.) Crankcase Fastener 8 N·m (71 in. lb.)

Blower Housing

Stud 10 N·m (88 in. lb.) Nut 8 N·m (70 in. lb.)

Brake

Mounting Fastener 9.5 N·m (84 in. lb.)

Breather Cover

Fastener 10 N·m (88 in. lb.)

Carburetor

Stud Fastener 8 N·m (71 in. lb.)

Values are in Metric units. Values in parentheses are English equivalents.

Exceeding maximum angle of operation may cause engine damage from insufcient lubrication.

Lubricate threads with engine oil prior to assembly.

Any and all horsepower (hp) references by Kohler are Certied Power Ratings and per SAE J1940 & J1995 hp

standards. Details on Certied Power Ratings can be found at KohlerEngines.com.

14 690 01 Rev. G KohlerEngines.com

Specications

TORQUE SPECIFICATIONS

3,5

XT-6, XTR-6

XT6.5, XT650,

XT6.75, XT675

XT-7, XTR-7,

XT775, XT8

Connecting Rod

Cap Fastener (torque in increments) 12.5 N·m (110 in. lb.)

Crankcase

Oil Drain Plug

13.6 N·m (120 in. lb.)

Oil Pan Screw 11.0 N·m (98 in. lb.) 14.7 N·m (130 in. lb.)

Cylinder Head

Fastener (torque in 2 increments) rst to 14 N·m (123 in. lb.)

nally to 27.8 N·m (246 in. lb.)

Flywheel

Retaining Nut 51.5 N·m (38 ft. lb.)

Fuel Tank

Bracket to Crankcase Stud 8 N·m (71 in. lb.) Bracket to Tank Fastener 4.5 N·m (40 in. lb.)

Governor

Lever Fastener 9.5 N·m (84 in. lb.) Gear Fastener 9.5 N·m (84 in. lb.)

Ignition

Spark Plug 27 N·m (20 ft. lb.) Module Fastener 10 N·m (88 in. lb.) Screw 10 N·m (88 in. lb.)

Mufer

Exhaust Stud 5.0 N·m (44 in. lb.) Exhaust Stud Nut Fastener 9.5 N·m (84 in. lb.)

Retractable Starter

Fastener 8 N·m (71 in. lb.)

Rocker Arm

Stud 13.6 N·m (120 in. lb.) Pivot Jam Nut 9.5 N·m (84 in. lb.)

Speed Control

Bracket Assembly Fastener 8 N·m (71 in. lb.)

Valve Cover

Fastener 8 N·m (71 in. lb.)

Values are in Metric units. Values in parentheses are English equivalents.

Lubricate threads with engine oil prior to assembly.

Apply thread sealant around three full threads before assembly. No excess sealant allowed on inside or outside of joint. Threads with preapplied sealant do not require use of additional sealant. Approved sealants include Perma-Loc LH 150, Perma-Loc MM 115, Perma-Loc HH 120, Perma-Loc HL 126.

KohlerEngines.com 14 690 01 Rev. G

Specications

CLEARANCE SPECIFICATIONS

XT-6, XTR-6

XT6.5, XT650,

XT6.75, XT675

XT-7, XTR-7,

XT775, XT8

Camshaft

End Play 0.3/0.85 mm (0.0118/0.0335 in.) Running Clearance 0.013/0.0555 mm (0.00051/0.00217 in.)

Connecting Rod

Connecting Rod-to-Crankpin Running Clearance New 0.025/0.045 mm (0.0009/0.0017 in.)

Connecting Rod-to-Crankpin Side Clearance New 0.03/0.48 mm

(0.00118/0.0189 in.)

0.13/0.58 mm

(0.0051/0.0228 in.)

Connecting Rod-to-Piston Pin Running Clearance 0.008/0.025 mm (0.0003/0.0009 in.) Piston Pin End I.D. New @ 21°C (70°F) 13.006/13.017 mm

(0.5120/0.5125 in.)

18.006/18.017 mm (0.7088/0.7093 in.)

Crankcase

Governor Cross Shaft Bore I.D. New 6.000/6.024 mm (0.2362/0.2372 in.)

Crankshaft

End Play (free) 0.427/1.298 mm (0.0168/0.05110 in.) Bore in Oil Pan I.D.

Early Models Later Models

25.400/25.421 mm (0.9999/1.0008 in.)

27.050/27.071 mm (1.06496/1.06578 in.)

Bore in Oil Pan Running Clearance Early Models Later Models

0.015/0.051 mm (0.0005/0.002 in.)

0.008/0.121 mm (0.0031/0.00476 in.)

Bearing (ywheel) Journal O.D. Early Models

Later Models

Max. Taper

Max. Out-of-Round

24.975/24.989 mm (0.9832/0.9838 in.)

25.005/25.019 mm (0.9844/0.9850 in.)

0.025 mm (0.0009 in.)

24.975/24.989 mm (0.9832/0.9838 in.)

0.025 mm (0.0009 in.)

Bearing (PTO) Journal O.D. Early Models Later Models

Max. Taper

Max. Out-of-Round

25.370/25.385 mm (0.9988/0.9994 in.)

26.95/26.97 mm (1.061/1.062 in.)

0.025 mm (0.0009 in.)

Connecting Rod Journal O.D. New

Max. Taper

Max. Out-of-Round

25.985/25.995 mm (1.0230/1.0234 in.)

0.010 mm (0.0004 in.)

29.985/29.995 mm (1.1805/1.1809 in.)

0.010 mm (0.0004 in.)

Cylinder Bore

Bore I.D. 65.00/65.02 mm

(2.559/2.560 in.)

Max. Out-of-Round

Max. Taper

0.0127 mm (0.0005 in.)

70.00/70.02 mm (2.755/2.756 in.)

Cylinder Head

Max. Out-of-Flatness 0.08 mm (0.003 in.)

Values are in Metric units. Values in parentheses are English equivalents.

14 690 01 Rev. G KohlerEngines.com

Specications

CLEARANCE SPECIFICATIONS

XT-6, XTR-6

XT6.5, XT650,

XT6.75, XT675

XT-7, XTR-7,

XT775, XT8

Governor

Governor Cross Shaft -to-Crankcase Running Clearance 0.020/0.064 mm (0.0007/0.0025 in.)

Cross Shaft O.D.

New 5.96/5.98 mm (0.2346/0.2354 in.)

Gear Shaft O.D.

New 6.01/6.03 mm (0.2366/0.2374 in.)

Governor Gear Shaft-to-Governor Gear Running Clearance 0.09/0.19 mm (0.0035/0.0074 in.)

Ignition

Spark Plug Gap 0.76 mm (0.030 in.)

Module Air Gap 0.254 mm (0.010 in.)

Piston, Piston Rings, and Piston Pin

Pin Bore I.D. 13.002/13.008 mm

(0.5118/0.5121 in.)

Pin O.D. 12.990/12.996 mm

(0.5114/0.5116 in.)

18.000/18.008 mm (0.7086/0.7089 in.)

17.990/17.996 mm (0.7082/0.7085 in.)

Top and Center Compression Ring Side Clearance

New Bore, Before Serial No. 40244XXXXX

New Bore, After Serial No. 40243XXXXX

0.02/0.06 mm (0.0007/0.0023 in.)

0.001/0.020 mm (0.00004/0.00080 in.)

Top and Center Compression Ring End Gap

New Bore, Before Serial No. 40244XXXXX

Top and Center

0.25/0.40 mm

(0.0098/0.0157 in.)

0.25/0.40 mm

(0.0098/0.0157 in.) New Bore, After Serial No. 40243XXXXX Top

Center

Thrust Face O.D. 64.975/64.985 mm

Piston Thrust Face-to-Cylinder Bore Running Clearance 0.025/0.035 mm

0.1/0.25 mm

(0.0039/0.0098 in.)

0.61/0.76 mm

(0.0240/0.0299 in.)

(0.2558/0.2558 in.)

(0.0010/0.0014 in.)

0.1/0.25 mm

(0.0039/0.0098 in.)

0.3/0.5 mm

(0.0118/0.0197 in.)

69.960/69.980 mm (2.7543/2.7551 in.)

0.020/0.060 mm

(0.0007/0.0024 in.)

Valves and Valve Lifters

Intake and Exhaust Valve Lash 0.0762/0.127 mm (0.003/0.005 in.) Intake Valve Stem-to-Valve Guide Running Clearance 0.020/0.047 mm (0.0007/0.0018 in.) Exhaust Valve Stem-to-Valve Guide Running Clearance 0.055/0.082 mm (0.0021/0.0032 in.) Intake Valve Guide I.D. 5.500/5.512 mm (0.2165/0.2170 in.) Intake Valve Stem Diameter 5.465/5.480 mm (0.2151/0.2157 in.) Exhaust Valve Guide I.D. 5.500/5.512 mm (0.2165/0.2170 in.) Exhaust Valve Stem Diameter 5.430/5.445 mm (0.2137/0.2143 in.) Nominal Valve Face Angle 25°, 45°, 60°

Values are in Metric units. Values in parentheses are English equivalents.

KohlerEngines.com 14 690 01 Rev. G

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

Size Grade 2 Grade 5 Grade 8

Tightening Torque: N·m (in. lb.) ± 20%

8-32 2.3 (20) 2.8 (25) — 2.3 (20) 10-24 3.6 (32) 4.5 (40) — 3.6 (32) 10-32 3.6 (32) 4.5 (40) — —

1/4-20 7.9 (70) 13.0 (115) 18.7 (165) 7.9 (70)

1/4-28 9.6 (85) 15.8 (140) 22.6 (200) — 5/16-18 17.0 (150) 28.3 (250) 39.6 (350) 17.0 (150) 5/16-24 18.7 (165) 30.5 (270) — —

3/8-16 29.4 (260) — — —

3/8-24 33.9 (300) — — —

Tightening Torque: N·m (ft. lb.) ± 20%

5/16-24 — — 40.7 (30) —

3/8-16 — 47.5 (35) 67.8 (50) —

3/8-24 — 54.2 (40) 81.4 (60) — 7/16-14 47.5 (35) 74.6 (55) 108.5 (80) — 7/16-20 61.0 (45) 101.7 (75) 142.5 (105) —

1/2-13 67.8 (50) 108.5 (80) 155.9 (115) —

1/2-20 94.9 (70) 142.4 (105) 223.7 (165) — 9/16-12 101.7 (75) 169.5 (125) 237.3 (175) — 9/16-18 135.6 (100) 223.7 (165) 311.9 (230) —

5/8-11 149.5 (110) 244.1 (180) 352.6 (260) —

5/8-18 189.8 (140) 311.9 (230) 447.5 (330) —

3/4-10 199.3 (147) 332.2 (245) 474.6 (350) —

3/4-16 271.2 (200) 440.7 (325) 637.3 (470) —

Specications

Into Aluminum

Metric Fastener Torque Recommendations for Standard Applications

Size

4.8

5.8

Property Class

8.8

10.9 12.9

Noncritical

Fasteners

Into Aluminum

Tightening Torque: N·m (in. lb.) ± 10%

M4 1.2 (11) 1.7 (15) 2.9 (26) 4.1 (36) 5.0 (44) 2.0 (18) M5 2.5 (22) 3.2 (28) 5.8 (51) 8.1 (72) 9.7 (86) 4.0 (35) M6 4.3 (38) 5.7 (50) 9.9 (88) 14.0 (124) 16.5 (146) 6.8 (60) M8 10.5 (93) 13.6 (120) 24.4 (216) 33.9 (300) 40.7 (360) 17.0 (150)

Tightening Torque: N·m (ft. lb.) ± 10%

M10 21.7 (16) 27.1 (20) 47.5 (35) 66.4 (49) 81.4 (60) 33.9 (25) M12 36.6 (27) 47.5 (35) 82.7 (61) 116.6 (86) 139.7 (103) 61.0 (45) M14 58.3 (43) 76.4 (56) 131.5 (97) 184.4 (136) 219.7 (162) 94.9 (70)

Torque Conversions

N·m = in. lb. x 0.113 in. lb. = N·m x 8.85

N·m = ft. lb. x 1.356 ft. lb. = N·m x 0.737

14 690 01 Rev. G KohlerEngines.com

Tools and Aids

Certain quality tools are designed to help you perform specic 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 Contact your local Kohler source of supply.

TOOLS

Description Source/Part No.

Alcohol Content Tester

For testing alcohol content (%) in reformulated/oxygenated fuels.

Camshaft Endplay Plate

For checking camshaft endplay.

Camshaft Seal Protector (Aegis)

For protecting seal during camshaft installation.

Cylinder Leakdown Tester

For checking combustion retention and if cylinder, piston, rings, or valves are worn. Individual component available: Adapter 12 mm x 14 mm (Required for leakdown test on XT-6 engines)

Dealer Tool Kit (Domestic)

Complete kit of Kohler required tools. Components of 25 761 39-S: Ignition System Tester Cylinder Leakdown Tester Oil Pressure Test Kit Rectier-Regulator Tester (120 V AC/60Hz)

Dealer Tool Kit (International)

Complete kit of Kohler required tools. Components of 25 761 42-S: Ignition System Tester Cylinder Leakdown Tester Oil Pressure Test Kit Rectier-Regulator Tester (240 V AC/50Hz)

Digital Vacuum/Pressure Tester

For checking crankcase vacuum. Individual component available: Rubber Adapter Plug

Electronic Fuel Injection (EFI) Diagnostic Software

For Laptop or Desktop PC.

EFI Service Kit

For troubleshooting and setting up an EFI engine. Components of 24 761 01-S: Fuel Pressure Tester Noid Light 90° Adapter In-line "T" Fitting Code Plug, Red Wire Code Plug, Blue Wire Shrader Valve Adapter Hose

Flywheel Puller

For properly removing ywheel from engine.

SE Tools 415 Howard St. Lapeer, MI 48446 Phone 810-664-2981 Toll Free 800-664-2981

Fax 810-664-8181

Design Technology Inc. 768 Burr Oak Drive Westmont, IL 60559 Phone 630-920-1300 Fax 630-920-0011

Kohler 25 455 11-S

SE Tools KLR-82405

SE Tools KLR-82417

Kohler 25 761 05-S

Design Technology Inc.

DTI-731-03

Kohler 25 761 39-S

Kohler 25 455 01-S Kohler 25 761 05-S Kohler 25 761 06-S Kohler 25 761 20-S

Kohler 25 761 42-S

Kohler 25 455 01-S Kohler 25 761 05-S Kohler 25 761 06-S Kohler 25 761 41-S

Design Technology Inc.

DTI-721-01

Design Technology Inc.

DTI-721-10

Kohler 25 761 23-S

Kohler 24 761 01-S

Design Technology Inc.

DTI-019 DTI-021 DTI-023 DTI-035 DTI-027 DTI-029 DTI-037

SE Tools KLR-82408

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Tools and Aids

TOOLS

Description Source/Part No.

Hydraulic Valve Lifter Tool

For removing and installing hydraulic lifters.

Ignition System Tester

For testing output on all systems, including CD.

Inductive Tachometer (Digital)

For checking operating speed (RPM) of an engine.

Offset Wrench (K and M Series)

For removing and reinstalling cylinder barrel retaining nuts.

Oil Pressure Test Kit

For testing/verifying oil pressure on pressure lubricated engines.

Rectier-Regulator Tester (120 volt current) Rectier-Regulator Tester (240 volt current)

For testing rectier-regulators. Components of 25 761 20-S and 25 761 41-S: CS-PRO Regulator Test Harness Special Regulator Test Harness with Diode

Spark Advance Module (SAM) Tester

For testing SAM (ASAM and DSAM) on engines with SMART-SPARK

™

Starter Servicing Kit (All Starters)

For removing and reinstalling drive retaining rings and brushes. Individual component available: Starter Brush Holding Tool (Solenoid Shift)

Triad/OHC Timing Tool Set

For holding cam gears and crankshaft in timed position while installing timing belt.

Valve Guide Reamer (K and M Series)

For properly sizing valve guides after installation.

Valve Guide Reamer O.S. (Command Series)

For reaming worn valve guides to accept replacement oversize valves. Can be used in low-speed drill press or with handle below for hand reaming.

Reamer Handle

For hand reaming using Kohler 25 455 12-S reamer.

Kohler 25 761 38-S

Kohler 25 455 01-S

Design Technology Inc.

DTI-110

Kohler 52 455 04-S

Kohler 25 761 06-S

Kohler 25 761 20-S Kohler 25 761 41-S

Design Technology Inc.

DTI-031 DTI-033

Kohler 25 761 40-S

SE Tools KLR-82411

SE Tools KLR-82416

Kohler 28 761 01-S

Design Technology Inc.

DTI-K828

Kohler 25 455 12-S

Design Technology Inc.

DTI-K830

AIDS Description Source/Part No.

Camshaft Lubricant (Valspar ZZ613) Kohler 25 357 14-S Dielectric Grease (GE/Novaguard G661) Kohler 25 357 11-S Dielectric Grease Loctite

51360

Kohler Electric Starter Drive Lubricant (Inertia Drive) Kohler 52 357 01-S Kohler Electric Starter Drive Lubricant (Solenoid Shift) Kohler 52 357 02-S RTV Silicone Sealant

Loctite Only oxime-based, oil resistant RTV sealants, such as those listed, are approved

5900® Heavy Body in 4 oz. aerosol dispenser.

for use. Loctite® Nos. 5900® or 5910® are recommended for best sealing characteristics.

Kohler 25 597 07-S

Loctite® 5910

Loctite® Ultra Black 598™

Loctite® Ultra Blue 587™

Loctite® Ultra Copper 5920™

Spline Drive Lubricant Kohler 25 357 12-S

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Tools and Aids

FLYWHEEL HOLDING TOOL ROCKER ARM/CRANKSHAFT TOOL

A ywheel holding tool can be made out of an old junk ywheel 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 ywheel ring gear teeth. Bosses will lock tool and ywheel in position for loosening, tightening, or removing with a

puller.

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 at.

3. Find a 1 in. long capscrew with correct thread size to match threads in connecting rod.

4. Use a at washer with correct I.D. to slip on capscrew and approximately 1 in. O.D. Assemble capscrew and washer to joint surface of rod.

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Troubleshooting

TROUBLESHOOTING GUIDE

When troubles occur, be sure to check simple causes which, at rst, 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 specication. 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 lter.

● 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.

● Insufcient 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).

● SMART-SPARKTM malfunction.

● Spark plug lead(s) disconnected.

Engine Starts But Does Not Keep Running

● Faulty carburetor.

● Faulty cylinder head gasket.

● Faulty or misadjusted choke or throttle controls.

● Fuel pump malfunction-vacuum hose clogged or leaking.

● Intake system leak.

● Loose wires or connections that intermittently ground ignition kill circuit.

● Quality of fuel (dirt, water, stale, mixture).

● Restricted fuel tank cap vent.

Engine Starts Hard

● Clogged fuel line or fuel lter.

● Engine overheated.

● Faulty ACR mechanism.

● Faulty or misadjusted choke or throttle controls.

● Faulty spark plug(s).

● Flywheel key sheared.

● Fuel pump malfunction-vacuum hose clogged or leaking.

● Interlock switch is engaged or faulty.

● Loose wires or connections that intermittently ground ignition kill circuit.

● Low compression.

● Quality of fuel (dirt, water, stale, mixture).

● Weak spark.

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 plug lead loose.

Engine Will Not Idle

● Engine overheated.

● Faulty spark plug(s).

● Idle fuel adjusting needle(s) improperly set.

● Idle speed adjusting screw improperly set.

● Inadequate fuel supply.

● Low compression.

● Quality of fuel (dirt, water, stale, mixture).

● Restricted fuel tank cap vent.

Engine Overheats

● Cooling fan broken.

● Excessive engine load.

● Fan belt failed/off.

● Faulty carburetor.

● High crankcase oil level.

● Lean fuel mixture.

● Low cooling system uid 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).

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Troubleshooting

Engine Loses Power

● Dirty air cleaner element.

● Engine overheated.

● Excessive engine load.

● Restricted exhaust.

● Faulty spark plug(s).

● High crankcase oil level.

● Incorrect governor setting.

● Low battery.

● Low compression.

● Low crankcase oil level.

● Quality of fuel (dirt, water, stale, mixture).

Engine Uses Excessive Amount of Oil

● Loose or improperly torqued fasteners.

● Blown head gasket/overheated.

● Breather reed broken.

● Clogged, broken, or inoperative crankcase breather.

● Crankcase overlled.

● Incorrect oil viscosity/type.

● Worn cylinder bore.

● Worn or broken piston rings.

● Worn valve stems/valve guides.

Oil Leaks from Oil Seals, Gaskets

● Breather reed broken.

● Clogged, broken, or inoperative crankcase breather.

● Loose or improperly torqued fasteners.

● Piston blow by, or leaky valves.

● Restricted exhaust.

EXTERNAL ENGINE INSPECTION

NOTE: It is good practice to drain oil at a location away

from workbench. Be sure to allow ample time for complete drainage.

Before cleaning or disassembling engine, make a thorough inspection of its external appearance and condition. This inspection can give clues to what might be found inside engines (and cause) when it is disassembled.

● Check for buildup of dirt and debris on crankcase, cooling ns, grass screen, and other external surfaces. Dirt or debris on these areas can cause overheating.

● Check for obvious fuel and oil leaks, and damaged components. Excessive oil leakage can indicate a clogged or inoperative breather, worn or damaged seals or gaskets, or loose fasteners.

● Check air cleaner cover and base for damage or indications of improper t and seal.

● Check air cleaner element. Look for holes, tears, cracked or damaged sealing surfaces, or other damage that could allow unltered air into engine. A dirty or clogged element could indicate insufcient or improper maintenance.

● Check carburetor throat for dirt. Dirt in throat is further indication that air cleaner was not functioning properly.

● Check if oil level is within operating range on dipstick. If it is above, sniff for gasoline odor.

● Check condition of oil. Drain oil into a container; it should ow 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

WARNING

Cleaning Solvents can cause severe injury or death.

Use only in well ventilated areas away from ignition sources.

Carburetor cleaners and solvents are extremely ammable. 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.

14 14 690 01 Rev. GKohlerEngines.com

CRANKCASE VACUUM TEST

Troubleshooting

WARNING

Carbon Monoxide can cause severe nausea, fainting or death.

Avoid inhaling exhaust fumes.

Engine exhaust gases contain poisonous carbon monoxide. Carbon monoxide is odorless, colorless, and can cause death if inhaled.

A 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:

1. Insert rubber stopper into oil ll hole. Be sure pinch clamp is installed on hose and use tapered adapters to connect hose between stopper and one manometer tube. Leave other tube open to atmosphere. Check that water level in manometer is at 0 line. Make sure pinch clamp is closed.

2. Start engine and run no-load high speed.

3. Open clamp and note water level in tube.

Level in engine side should be a minimum of 10.2

cm (4 in.) above level in open side.

If level in engine side is less than specied (low/no

vacuum), or level in engine side is lower than level in open side (pressure), check for conditions in table below.

4. Close pinch clamp before stopping engine.

Keep hands, feet, hair, and clothing away from all moving parts to prevent injury. Never operate engine with covers, shrouds, or guards removed.

To test crankcase vacuum with vacuum/pressure gauge:

1. Remove dipstick or oil ll plug/cap.

2. Install adapter into oil ll//dipstick tube opening,

3. Run engine and observe gauge reading. Analog tester–needle movement to left of 0 is a

Digital tester–depress test button on top of tester. Crankcase vacuum should be a minimum of 10.2 cm

Rotating Parts can cause severe injury. Stay away while engine is in operation.

upside down over end of a small diameter dipstick tube, or directly into engine if a tube is not used. Insert barbed gauge tting into hole in stopper.

vacuum, and movement to right indicates a pressure.

(4 in.) of water. If reading is below specication, or if pressure is present, check table below for possible causes and conclusions.

WARNING

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 atness, reassemble, and recheck pressure.

Seals and/or gaskets leaking. Loose or improperly torque fasteners.

Piston blow by or leaky valves (conrm by inspecting components).

Restricted exhaust. Check exhaust screen/spark arrestor (if equipped). Clean

Replace all worn or damaged seals and gaskets. Make sure all fasteners are tightened securely. Use appropriate torque valves and sequences when necessary.

Recondition piston, rings, cylinder bore, valves and valves guides.

or replace as needed. Repair or replace any other damaged/restricted mufer or exhaust system parts.

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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 difcult 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 lter from engine.

3. Rotate crankshaft until piston (of cylinder being tested) is at top dead center (TDC) of compression stroke. Hold engine in this position while testing. Holding tool supplied with tester can be used if PTO end of crankshaft is accessible. Lock holding tool onto crankshaft. Install a 3/8 in. breaker bar into hole/slot of holding tool, so it is perpendicular to both holding tool and crankshaft PTO.

If ywheel end is more accessible, use a breaker bar and socket on ywheel nut/screw to hold it in position. An

assistant may be needed to hold breaker bar during testing. If engine is mounted in a piece of equipment, it may be possible to hold it by clamping or wedging a driven component. Just be certain that engine cannot rotate off of TDC in either direction.

4. Install adapter into spark plug hole, but do not attach it to tester at this time.

5. Turn regulator knob completely counterclockwise.

6. Connect an air source of at least 50 psi to tester.

7. Turn regulator knob clockwise (increase direction) until gauge needle is in yellow set area at low end of scale.

8. Connect tester quick-connect to adapter hose. While rmly holding engine at TDC, gradually open tester valve. Note gauge reading and listen for escaping air at combustion air intake, exhaust outlet, and crankcase breather.

Condition Conclusion

Air escaping from crankcase breather. Ring or cylinder worn. Air escaping from exhaust system. Defective exhaust valve/improper seating. Air escaping from intake. Defective intake valve/improper seating. Gauge reading in low (green) zone. Piston rings and cylinder in good condition. Gauge reading in moderate (yellow) zone. Engine is still usable, but there is some wear present.

Customer should start planning for overhaul or replacement.

Gauge reading in high (red) zone. Rings and/or cylinder have considerable wear. Engine

should be reconditioned or replaced.

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Air Cleaner/Intake

AIR CLEANER

These systems are CARB/EPA certied and components should not be altered or modied in any way.

Air Cleaner Components

Precleaner (if equipped)

1. Remove precleaner.

2. Replace or wash precleaner in warm water with detergent. Rinse and allow to air dry.

3. Reinstall precleaner into cover, aligning hole in precleaner with upper cover knob.

Paper Element

1. Remove paper element from base and replace.

2. Install element with pleated side out and seat rubber seal onto edges of base.

Foam Element

1. Remove foam element from base and replace.

2. Install element with foam side out and seat rubber seal onto edges of base.

Reinstall air cleaner cover and secure with knob or latch.

BREATHER TUBE

Make sure both ends of breather tube are properly connected.

AIR COOLING

WARNING

Hot Parts can cause severe burns. Do not touch engine while operating or just

after stopping.

Never operate engine with heat shields or guards removed.

Proper cooling is essential. To prevent over heating, clean screens, cooling ns, and other external surfaces of engine. Avoid spraying water at wiring harness or any electrical components. Refer to Maintenance Schedule.

A Air Cleaner Cover B Precleaner C Paper Element D Base E Air Cleaner Knob F Air Cleaner Latch

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 or unhook latch and remove air cleaner cover.

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