XT-6, XTR-6, XT6.5, XT650, XT6.75, XT675, XT-7, XTR-7, XT775

114 690 01 Rev. G KohlerEngines.com

XT-6, XTR-6, XT6.5, XT650, XT6.75, XT675,

XT-7, XTR-7, XT775, XT8

Service Manual

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

IMPORTANT: Read all safety precautions and instructions carefully before operating equipment. Refer to operating

instruction of equipment that this engine powers.

Ensure engine is stopped and level before performing any maintenance or service.

Safety

KohlerEngines.com 14 690 01 Rev. G

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.

WARNING

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.

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.

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.

CAUTION

Electrical Shock can

cause injury.

Do not touch wires while

engine is running.

CAUTION

Damaging Crankshaft

and Flywheel can cause

personal injury.

Using improper procedures can

lead to broken fragments. Broken

fragments could be thrown from

engine. Always observe and use

precautions and procedures when

installing ywheel.

WARNING

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.

Maintenance

14 690 01 Rev. G KohlerEngines.com

MAINTENANCE INSTRUCTIONS

WARNING

Before working on engine or equipment, disable engine as

follows: 1) Disconnect spark plug lead(s). 2) Disconnect

negative (–) battery cable from battery.

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).

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).

Maintenance

KohlerEngines.com 14 690 01 Rev. G

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.

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.

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.

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.

Specications

14 690 01 Rev. G KohlerEngines.com

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)

20°

TORQUE SPECIFICATIONS

3,5

XT-6, XTR-6

XT6.5, XT650,

XT6.75, XT675

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.

Specications

KohlerEngines.com 14 690 01 Rev. G

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.

Specications

14 690 01 Rev. G KohlerEngines.com

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.)

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.)

70.00/70.02 mm

(2.755/2.756 in.)

Max. Out-of-Round

Max. Taper

0.0127 mm (0.0005 in.)

Cylinder Head

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

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

Specications

KohlerEngines.com 14 690 01 Rev. G

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.)

18.000/18.008 mm

(0.7086/0.7089 in.)

Pin O.D. 12.990/12.996 mm

(0.5114/0.5116 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

New Bore, After Serial No. 40243XXXXX

Top

Center

0.25/0.40 mm

(0.0098/0.0157 in.)

0.1/0.25 mm

(0.0039/0.0098 in.)

0.61/0.76 mm

(0.0240/0.0299 in.)

0.25/0.40 mm

(0.0098/0.0157 in.)

0.1/0.25 mm

(0.0039/0.0098 in.)

0.3/0.5 mm

(0.0118/0.0197 in.)

Thrust Face O.D. 64.975/64.985 mm

(0.2558/0.2558 in.)

69.960/69.980 mm

(2.7543/2.7551 in.)

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

(0.0010/0.0014 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.

Specications

14 690 01 Rev. G KohlerEngines.com

GENERAL TORQUE VALUES

Metric Fastener Torque Recommendations for Standard Applications

Property Class

Noncritical

Fasteners

Into Aluminum

Size

4.8

5.8

8.8

10.9 12.9

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

English Fastener Torque Recommendations for Standard Applications

Bolts, Screws, Nuts and Fasteners Assembled Into Cast Iron or Steel

Grade 2 or 5 Fasteners

Into Aluminum

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) —

Tools and Aids

10 14 690 01 Rev. GKohlerEngines.com

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.

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

TOOLS

Description Source/Part No.

Alcohol Content Tester

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

Kohler 25 455 11-S

Camshaft Endplay Plate

For checking camshaft endplay.

SE Tools KLR-82405

Camshaft Seal Protector (Aegis)

For protecting seal during camshaft installation.

SE Tools KLR-82417

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)

Kohler 25 761 05-S

Design Technology Inc.

DTI-731-03

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)

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

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)

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

Digital Vacuum/Pressure Tester

For checking crankcase vacuum.

Individual component available:

Rubber Adapter Plug

Design Technology Inc.

DTI-721-01

Design Technology Inc.

DTI-721-10

Electronic Fuel Injection (EFI) Diagnostic Software

For Laptop or Desktop PC.

Kohler 25 761 23-S

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

Kohler 24 761 01-S

Design Technology Inc.

DTI-019

DTI-021

DTI-023

DTI-035

DTI-027

DTI-029

DTI-037

Flywheel Puller

For properly removing ywheel from engine.

SE Tools KLR-82408

Tools and Aids

1114 690 01 Rev. G KohlerEngines.com

TOOLS

Description Source/Part No.

Hydraulic Valve Lifter Tool

For removing and installing hydraulic lifters.

Kohler 25 761 38-S

Ignition System Tester

For testing output on all systems, including CD.

Kohler 25 455 01-S

Inductive Tachometer (Digital)

For checking operating speed (RPM) of an engine.

Design Technology Inc.

DTI-110

Offset Wrench (K and M Series)

For removing and reinstalling cylinder barrel retaining nuts.

Kohler 52 455 04-S

Oil Pressure Test Kit

For testing/verifying oil pressure on pressure lubricated engines.

Kohler 25 761 06-S

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

Kohler 25 761 20-S

Kohler 25 761 41-S

Design Technology Inc.

DTI-031

DTI-033

Spark Advance Module (SAM) Tester

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

™

Kohler 25 761 40-S

Starter Servicing Kit (All Starters)

For removing and reinstalling drive retaining rings and brushes.

Individual component available:

Starter Brush Holding Tool (Solenoid Shift)

SE Tools KLR-82411

SE Tools KLR-82416

Triad/OHC Timing Tool Set

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

Kohler 28 761 01-S

Valve Guide Reamer (K and M Series)

For properly sizing valve guides after installation.

Design Technology Inc.

DTI-K828

Valve Guide Reamer O.S. (Command Series)

For reaming worn valve guides to accept replacement oversize valves. Can be used

in low-speed drill press or with handle below for hand reaming.

Kohler 25 455 12-S

Reamer Handle

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

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

5900

Heavy Body in 4 oz. aerosol dispenser.

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

for use. Loctite

Nos. 5900

or 5910

are recommended for best sealing

characteristics.

Kohler 25 597 07-S

Loctite

5910

Loctite

Ultra Black 598™

Loctite

Ultra Blue 587™

Loctite

Ultra Copper 5920™

Spline Drive Lubricant Kohler 25 357 12-S

Tools and Aids

12 14 690 01 Rev. GKohlerEngines.com

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.

1314 690 01 Rev. G KohlerEngines.com

Troubleshooting

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-SPARK

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.

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 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).

Troubleshooting

14 14 690 01 Rev. GKohlerEngines.com

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.

1514 690 01 Rev. G KohlerEngines.com

Troubleshooting

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.

Replace all worn or damaged seals and gaskets. Make

sure all fasteners are tightened securely. Use appropriate

torque valves and sequences when necessary.

Piston blow by or leaky valves (conrm by inspecting

components).

Recondition piston, rings, cylinder bore, valves and

valves guides.

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

or replace as needed. Repair or replace any other

damaged/restricted mufer or exhaust system parts.

CRANKCASE VACUUM TEST

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.

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.

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,

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.

3. Run engine and observe gauge reading.

Analog tester–needle movement to left of 0 is a

vacuum, and movement to right indicates a pressure.

Digital tester–depress test button on top of tester.

Crankcase vacuum should be a minimum of 10.2 cm

(4 in.) of water. If reading is below specication, or if

pressure is present, check table below for possible

causes and conclusions.

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.

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.

Troubleshooting

16 14 690 01 Rev. GKohlerEngines.com

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.

Air Cleaner/Intake

14 690 01 Rev. G KohlerEngines.com

AIR CLEANER

These systems are CARB/EPA certied and components

should not be altered or modied in any way.

Air Cleaner Components

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.

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.

Fuel System

KohlerEngines.com 14 690 01 Rev. G

Typical carbureted fuel system and related components

include:

● Fuel tank.

● Fuel line.

● In-line fuel lter.

● Fuel tank lter (in-nipple).

● Fuel shut-off valve (if equipped).

● Carburetor.

Fuel tank outlet is located above carburetor inlet,

allowing gravity to feed fuel through in-line lter and fuel

line to carburetor.

Fuel enters carburetor through fuel shut-off valve and

sediment bowl and then goes to carburetor oat bowl.

Fuel is drawn into carburetor body and mixed with air.

This fuel-air mixture is then burned in engine combustion

chamber.

FUEL RECOMMENDATIONS

Refer to Maintenance.

FUEL LINE

Low permeation fuel line must be installed on carbureted

Kohler Co. engines to maintain EPA and CARB

regulatory compliance.

FUEL SHUT-OFF (if equipped)

Some engines are equipped with a fuel shut-off located

at carburetor. It controls fuel ow from tank to carburetor.

FUEL SYSTEM TESTS

When engine starts hard, or turns over but will not start, fuel system might be causing problems. Test fuel system by

performing following tests.

1. Check for fuel in combustion chamber.

a. Disconnect and ground spark plug lead.

b. Close choke on carburetor.

c. Crank engine several times.

d. Remove spark plug and check for fuel at tip.

2. Check for fuel ow from tank to carburetor.

a. Remove fuel line from inlet tting of carburetor.

b. Use an approved fuel container to catch fuel, and

hold line below bottom of tank to observe fuel

ow.

3. Check operation of fuel shut-off valve.

a. Remove fuel sediment bowl under inlet tting of

carburetor.

b. Turn fuel shut-off valve ON and OFF and observe

operation.

Condition Conclusion

Fuel at tip of spark plug. Fuel is reaching combustion chamber.

No fuel at tip of spark plug. Check fuel ow from fuel tank (step 2).

Fuel ows from fuel line. Check operation of fuel shut-off valve (step 3).

No fuel ow from fuel line. Check fuel tank vent, in-line lter threaded into tank, and

fuel line. Correct any observed problem and reconnect

line.

Fuel ows from valve. Check for dirt and water in sediment bowl and screen.

Clean bowl and screen as needed. Check for faulty

carburetor, refer to Carburetor.

No fuel ows from valve. Check for a restriction in fuel shut-off valve or inlet elbow.

Fuel System

14 690 01 Rev. G KohlerEngines.com

CARBURETOR

WARNING

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.

Explosive Fuel can cause res and severe

burns.

Do not ll fuel tank while engine is hot or

running.

Typical One-Barrel Carburetor Components

Low Idle Speed

Adjusting Screw

B Idle Jet

C Fuel Shut-Off Gasket D Wave Washer

E Fuel Shut-Off Valve F Main Nozzle Tube

G Main Jet H Bowl Gasket

I Fuel Inlet Needle J Spring

K Hinge Pin L Float

M Fuel Bowl N

Bowl Retaining Screw

Gasket

O Bowl Retaining Screw

These engines are equipped with a xed main jet

carburetor. Carburetor is designed to deliver correct fuel-

to-air mixture to engine under all operating conditions.

Idle mixture is set at factory and cannot be adjusted.

Troubleshooting Checklist

When engine starts hard, runs rough, or stalls at low

idle speed, check these areas before adjusting or

disassembling carburetor.

1. Make sure fuel tank is lled with clean, fresh

gasoline.

2. Make sure fuel tank cap vent is not blocked and is

operating properly.

3. Make sure fuel is reaching carburetor. This includes

checking fuel shut-off valve, fuel tank lter screen,

in-line fuel lter, fuel lines and fuel pump for

restrictions or faulty components as necessary.

4. Make sure air cleaner base and carburetor are

securely fastened to engine using gaskets in good

condition.

5. Make sure air cleaner element (including precleaner

if equipped) is clean and all air cleaner components

are fastened securely.

6. Make sure ignition system, governor system,

exhaust system, and throttle and choke controls are

operating properly.

Fuel System

KohlerEngines.com 14 690 01 Rev. G

Troubleshooting-Carburetor Related Causes

Condition Possible Cause Conclusion

Engine starts hard, runs rough, or

stalls at idle speed.

Low idle fuel mixture (some models)/

speed improperly adjusted.

Adjust idle speed screw or clean

carburetor.

Engine runs rich (indicated by black,

sooty exhaust smoke, misring, loss

of speed and power, governor

hunting, or excessive throttle

opening).

Clogged air cleaner. Clean or replace air cleaner.

Choke partially closed during

operation.

Check choke lever/linkage to ensure

choke is operating properly.

Dirt under fuel inlet needle. Remove needle; clean needle and

seat and blow with compressed air.

Bowl vent or air bleeds plugged. Clean vent, ports, and air bleeds.

Blow out all passages with

compressed air.

Leaky, cracked, or damaged oat. Submerge oat to check for leaks.

Engine runs lean (indicated by

misring, loss of speed and power,

governor hunting, or excessive

throttle opening).

Idle holes plugged; dirt in fuel delivery

channels.

Clean main fuel jet and all passages;

blow out with compressed air.

Fuel leaks from carburetor. Float damaged. Submerge oat to check for leaks.

Replace oat.

Dirt under fuel inlet needle. Remove needle; clean needle and

seat and blow with compressed air.

Bowl vents plugged. Blow out with compressed air.

Carburetor bowl gasket leaks. Replace gasket.

Carburetor Circuits

Float

Fuel level in bowl is maintained by oat and fuel inlet

needle. Buoyant force of oat stops fuel ow when

engine is at rest. When fuel is being consumed, oat will

drop and fuel pressure will push inlet needle away from

seat, allowing more fuel to enter bowl. When demand

ceases, buoyant force of oat will again overcome fuel

pressure, rising to predetermined setting and stop ow.

Slow and Mid-Range

At low speeds engine operates only on slow circuit. As

a metered amount of air is drawn through slow air bleed

jets, fuel is drawn through main jet and further metered

through slow jet. Air and fuel are mixed in body of slow

jet and exit to idle progression (transfer port) chamber.

From idle progression chamber, air fuel mixture is

metered through idle port passage. At low idle air/fuel

mixture is controlled by setting of idle fuel adjusting

screws. This mixture is then mixed with main body of

air and delivered to engine. As throttle plate opening

increases, greater amounts of air/fuel mixture are drawn

in through xed and metered idle progression holes.

As throttle plate opens further, vacuum signal becomes

great enough at venturi so main circuit begins to work.

Main (high-speed)

At high speeds/loads engine operates on main circuit.

As a metered amount of air is drawn through air jet,

fuel is drawn through main jet. Air and fuel are mixed

in main nozzles then enters main body of airow where

further mixing of fuel and air occurs. This mixture is then

delivered to combustion chamber. Carburetor has a xed

main circuit; no adjustment is possible.

Carburetor Adjustments

NOTE: Carburetor adjustments should be made only

after engine has warmed up.

Carburetor is designed to deliver correct fuel-to-air

mixture to engine under all operating conditions. Main

fuel jet is calibrated at factory and is not adjustable. Idle

fuel adjusting needles are also set at factory and are not

adjustable.

Low Idle Speed (RPM) Adjustment

NOTE: Actual low idle speed depends on application.

Refer to equipment manufacturer’s

recommendations. Low idle speed for basic

engines is 1800 RPM.

Place throttle control into idle or slow position. Turn low

idle speed adjusting screw in or out to obtain allow idle

speed of 1800 RPM (± 75 RPM).

Carburetor Servicing

WARNING

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.

NOTE: Main and slow jets are xed and size specic

and can be removed if required. Fixed jets for

high altitudes are available.

Fuel System

14 690 01 Rev. G KohlerEngines.com

● Inspect carburetor body for cracks, holes, and other

wear or damage.

● Inspect oat for cracks, holes, and missing or

damaged oat tabs. Check oat hinge and shaft for

wear or damage.

● Inspect fuel inlet needle and seat for wear or damage.

1. Perform removal procedures for appropriate air

cleaner and carburetor outlined in Disassembly.

2. Clean exterior surfaces of dirt or foreign material

before disassembling carburetor. Remove bowl

retaining screws, and carefully separate fuel bowl

from carburetor. Do not damage fuel bowl O-rings.

Transfer any remaining fuel into an approved

container. Save all parts. Fuel can also be drained

prior to bowl removal by loosening/removing bowl

drain screw.

3. Remove oat pin and inlet needle. Seat for inlet

needle is not serviceable and should not be

removed.

4. Clean carburetor bowl and inlet seat areas as

required.

5. Carefully remove main jet from carburetor. After

main jet is removed, main nozzles can be removed

through bottom of main towers. Note orientation/

direction of nozzles. End with 2 raised shoulders

should be out/down adjacent to main jets.

6. Save parts for cleaning and reuse unless a jet kit is

also being installed. Clean slow jets using

compressed air or carburetor cleaner, do not use

wire.

NOTE: There are 2 O-rings on body of idle jet.

Carburetor is now disassembled for appropriate cleaning

and installation of parts in overhaul kit. See instructions

provided with repair kits for more detailed information.

High Altitude Operation

Engines may require a high altitude carburetor kit to

ensure correct engine operation at altitudes above 1219

meters (4000 ft.). To obtain high altitude kit information

or to nd a Kohler authorized dealer visit KohlerEngines.

com or call 1-800-544-2444 (U.S. and Canada).

This engine should be operated in its original

conguration below 1219 meters (4000 ft.) as damage

may occur if high altitude carburetor kit is installed and

operated below 1219 meters (4000 ft.).

Auto Choke Troubleshooting (if equipped)

If engine is equipped with auto choke, identify design

and follow appropriate troubleshooting procedure.

NOTE: Procedures may be easier to perform with

engine cover removed. Refer to Disassembly/

Inspection and Service and Reassembly

procedure.

Auto Choke Components - Vacuum/Diaphragm

Design

Bimetallic Spring

Housing

B Linkage

C Diaphragm Assembly D Choke Plate

E Vacuum Hose

A bimetallic spring reacts to mufer heat and moves

linkage that opens or closes choke. A diaphragm that

operates from intake manifold vacuum assists spring

system. These two elements work together to operate

a smooth choke system that facilitates easy reliable

starting.

Use following procedures to troubleshoot vacuum/

diaphragm design auto choke system and its

components. These procedures are to be performed on

a cold engine.

Cover, Element, and Breather Cover

A Air Cleaner Cover B Element

C Breather Cover D Air Cleaner Base

1. Remove air cleaner cover, air cleaner, and breather

cover from air cleaner base.

2. Check choke linkage for binding or debris build up.

Gently actuate linkage and observe that choke plate

has full range of movement (open and close).

Fuel System

KohlerEngines.com 14 690 01 Rev. G

3. Remove vacuum hose from carburetor vacuum

tting. Attach a vacuum gauge or manometer to

carburetor vacuum tting. Run engine while holding

choke plate open. Gauge should indicate a vacuum

with a minimum of 15" of water. If reading is correct,

check again for binding of restricted linkage.

4. If vacuum indicated is less than 15" of water,

problem is not an auto choke issue.

Diaphragm Assembly and Hose

A Choke Plate B Vacuum Hose

C Vacuum Fitting D Diaphragm Assembly

5. Note position of choke plate. Attach a vacuum pump

to vacuum hose. Choke plate should open 1/2 to 3/4

under vacuum and with a minimum of 15" of water. If

diaphragm assembly is unable to open choke plate,

check hose for cracks, leaks, or restrictions. If

necessary replace vacuum hose. If hose is in

working condition and choke plate fails to open with

specied vacuum, or diaphragm fails to hold choke

plate open for a minimum of 3 seconds, replace

diaphragm assembly.

6. Attach vacuum hose to carburetor vacuum tting.

7. Start engine. Upon start up choke plate should be

1/2 to 3/4 open. Choke plate should gradually

change to full open position after 2 to 2-1/2 minutes

of running. This action is performed by bimetallic

spring assembly being heated. If choke plate fails to

open, recheck linkage for binding. If necessary

replace bimetallic spring assembly.

NOTE: Inspect to ensure choke linkage is not binding.

Choke Plate and Bimetallic Spring Housing

A Choke Plate B

Bimetallic Spring

Assembly

Fuel System

14 690 01 Rev. G KohlerEngines.com

Auto Choke Components - Link Design

Bimetallic Spring

Housing

B Wire Choke Linkage

C Choke Plate D Choke Lever

E Choke Link

When engine is cold, spring around base of choke shaft

holds choke closed for starting. When engine starts,

governor closes throttle from wide open to set governor

speed. As throttle closes, link between throttle and choke

operates choke to a slightly open position. After engine

warms up, bimetallic spring overcomes choke shaft

spring force and holds choke completely open.

Use these steps to check function of link design auto

choke.

1. Remove air cleaner cover and element.

2. Choke plate should be fully close when engine is

cold.

3. There should be light spring tension holding choke

closed.

4. There should not be any binding when choke shaft

assembly is rotated, which could cause choke to

remain partially open.

5. When engine is started, choke plate should be 1/3

open. Choke plate should start to open and be

completely open within 2 to 3 minutes at room

temperature.

6. Reinstall air cleaner element and secure cover.

Governor System

KohlerEngines.com 14 690 01 Rev. G

Governed speed setting is determined by position of

throttle control. It can be variable or constant, depending

on engine application.

Governor is designed to hold engine speed constant

under changing load conditions. Most engines are

equipped with a centrifugal yweight mechanical

governor. Governor gear/yweight mechanism of

mechanical governor is mounted inside crankcase and is

driven off gear on camshaft.

This governor design works as follows:

● Centrifugal force acting on rotating governor gear

assembly causes yweights to move outward as

speed increases. Governor spring tension moves

them inward as speed decreases.

GOVERNOR

Governor Components

A Control Spring B

Intermediate Control

Lever

C Control Bracket D Governor Lever

E Compression Spring F Linkage G Regulating Pin H Flyweight(s)

I Governor Gear J Governor Gear Shaft K

Governor Shaft

Retainer

● As yweights move outward, they cause regulating pin

to move outward.

● Regulating pin contacts tab on cross shaft causing

shaft to rotate.

● One end of cross shaft protrudes through crankcase.

Rotating action of cross shaft is transmitted to throttle

lever of carburetor through external throttle linkage.

● When engine is at rest, and throttle is in fast position,

tension of governor spring holds throttle plate open.

When engine is operating, governor gear assembly is

rotating. Force applied by regulating pin against cross

shaft tends to close throttle plate. Governor spring

tension and force applied by regulating pin balance

each other during operation, to maintain engine

speed.

Governor System

14 690 01 Rev. G KohlerEngines.com

● When load is applied and engine speed and governor

gear speed decreases, governor spring tension moves

governor arm to open throttle plate wider. This allows

more fuel into engine, increasing engine speed. As

speed reaches governed setting, governor spring

tension and force applied by regulating pin will again

offset each other to hold a steady engine speed.

Initial Governor Adjustment

Make this initial adjustment whenever governor arm is

loosened or removed from cross shaft. To ensure proper

adjustment, make sure throttle linkage is connected to

both governor arm and throttle lever on carburetor.

1. Loosen governor lever adjustment screw.

2. Move governor lever away from carburetor (wide

open throttle). Do not apply excess force that may

ex or distort throttle link.

3. Grasp cross shaft with a pliers and turn shaft

clockwise as far as it will go. Then torque nut to

9.5 N·m (84 in. lb.).

4. Rotate governor shaft clockwise until it stops.

5. Hold both in this position and torque governor lever

bolt to 10 N·m (88.5 in. lb.).

Lubrication System

KohlerEngines.com 14 690 01 Rev. G

These engines use a splash lubrication system, supplying necessary lubrication to crankshaft, camshaft, connecting

rod, and valve train components.

Lubrication Components

OIL RECOMMENDATIONS

Refer to Maintenance.

CHECK OIL LEVEL

NOTE: To prevent extensive engine wear or damage,

never run engine with oil level below or above

operating range indicator on dipstick.

Ensure engine is cool. Clean oil ll cap/dipstick areas of

any debris.

1. Remove dipstick; wipe oil off.

a. 1/4 turn cap: reinsert dipstick into tube; press

completely down and turn 1/4 turn.

b. Threaded 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.

4. Reinstall and secure dipstick.

CHANGE OIL

Change oil while engine is warm.

Dipstick tube

1. Clean area around oil ll cap/dipstick.

2. Remove oil ll cap/dipstick. Tilt engine on its side

with air cleaner facing up. Drain oil into appropriate

container.

3. After crankcase is drained completely, tilt engine

upright.

4. Fill crankcase with new oil. Level should be at top of

indicator on dipstick.

5. Reinstall oil ll cap/dipstick and tighten securely.

6. Dispose of used oil in accordance with local

ordinances.

Crankcase plug

1. Disable engine by disconnecting spark plug.

2. Clean area around oil ll cap/dipstick. Remove oil ll

cap/dipstick.

3. Remove crankcase plug on bottom of engine; drain

oil into appropriate container.

4. Apply thread sealant around three full threads of

drain plug; reinstall drain plug. Torque drain plug to

13.6 N·m (120 in. lb.).

5. Fill crankcase with new oil. Level should be at top of

indicator on dipstick.

6. Reinstall oil ll cap/dipstick and tighten securely.

7. Dispose of used oil in accordance with local

ordinances.

A 1/4 Turn Cap B Threaded Cap C Air Cleaner D Crankcase Plugs

A B

Electrical System

14 690 01 Rev. G KohlerEngines.com

SPARK PLUGS

CAUTION

Electrical Shock can cause injury.

Do not touch wires while engine is running.

Spark Plug Component and Details

A Wire Gauge B Spark Plug

C Ground Electrode D Gap

NOTE: Do not clean spark plug in a machine using

abrasive grit. Some grit could remain in spark

plug and enter engine causing extensive wear

and damage.

Engine misre or starting problems are often caused

by a spark plug that has improper gap or is in poor

condition.

Engine is equipped with following spark plugs:

XT-6, XTR-6,

XT6.5, XT6.75,

XT650, XT675,

XT775, XT8*

XT-7, XTR-7,

XT8*

Gap 0.76 mm (0.03 in.) 0.76 mm (0.03 in.)

Thread Size 12 mm 14 mm

Reach 19.1 mm (3/4 in.) 19.1 mm (3/4 in.)

Hex Size 18 mm (3/4 in.) 15.9 mm (5/8 in.)

Refer to Maintenance for Repairs/Service Parts.

*Order replacement spark plug based on size in XT8

engine being serviced.

Service

Clean out spark plug recess. Remove plug and replace.

1. Check gap using wire feeler gauge. Adjust gap to

0.76 mm (0.03 in.).

2. Install plug into cylinder head.

3. Torque plug to 27 N·m (20 ft. lb.).

Inspection

Inspect each spark plug as it is removed from cylinder

head. Deposits on tip are an indication of general

condition of piston rings, valves, and carburetor.

Normal and fouled plugs are shown in following photos:

Normal

Plug taken from an engine operating under normal

conditions will have light tan or gray colored deposits. If

center electrode is not worn, plug can be set to proper

gap and reused.

Worn

On a worn plug, center electrode will be rounded and

gap will be greater than specied gap. Replace a worn

spark plug immediately.

Wet Fouled

A wet plug is caused by excess fuel or oil in combustion

chamber. Excess fuel could be caused by a restricted air

cleaner, a carburetor problem, or operating engine with

too much choke. Oil in combustion chamber is usually

caused by a restricted air cleaner, a breather problem,

worn piston rings, or valve guides.

Electrical System

KohlerEngines.com 14 690 01 Rev. G

Carbon Fouled

Soft, sooty, black deposits indicate incomplete

combustion caused by a restricted air cleaner, over rich

carburetion, weak ignition, or poor compression.

Overheated

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.

Electrical System

14 690 01 Rev. G KohlerEngines.com

CDI Module Operation (aluminum ywheel)

Ignition System Components

Kill Switch/

Off Position of

Key Switch

B Flywheel

C Magnet D Ignition Module

E Lamination F Kill Terminal

G Spark Plug H Spark Plug Boot

I Spark Plug Terminal J

Air Gap

0.254 mm (0.010 in.)

As ywheel rotates and magnet passes CDI ignition

module, magnetic eld induces current in charging coil.

Current pulse is rectied by a diode and this signal

charges a high-voltage capacitor. As magnet completes

its pass, a change in polarity of signal produced by

ywheel magnet turns on semiconductor switch, and

directly connects charged capacitor to primary coil of

transformer. As capacitor discharges energy, low voltage

at primary winding is transformed to high voltage in

secondary winding of module. A high voltage pulse

is then delivered to spark plug, where it arcs across

electrode gap and ignites fuel in combustion chamber.

This system consists of following components:

● Magnets, permanently afxed to ywheel.

● Spark plug with rubber boot.

● Electronic, capacitive discharge ignition module

mounted on engine crankcase.

● Kill switch (or key switch); grounds module to stop

engine.

ELECTRONIC IGNITION SYSTEM

These engines are equipped with dependable solid-state magneto ignition systems. Two types of ignition modules are

used on these engines, capacitive discharge ignition (CDI), and inductive discharge ignition (IDI).

Both 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 t snugly. Make sure ignition switch is in run position.

IDI Module Operation (cast iron ywheel)

Ignition System Components

Kill Switch/

Off Position of

Key Switch

B Flywheel

C Magnet D Ignition Module

E Lamination F Kill Terminal

G Spark Plug H Spark Plug Boot

I Spark Plug Terminal J

Air Gap

0.254 mm (0.010 in.)

As ywheel rotates and magnet passes IDI ignition

module, magnetic eld induces current in primary

coil. As ignition magnet completes its pass, it induces

current in a small triggering coil, which then turns on a

semiconductor switch. This causes previously induced

magnetic eld in primary coil to collapse. As magnetic

eld collapses, it causes voltage in secondary coil to

rise quickly. This sharp rise in voltage is sufcient to

arc across spark plug’s gap, and ignite fuel mixture in

combustion chamber. This system consists of following

components:

● Magnets, permanently afxed to ywheel.

● Spark plug with metal boot.

● Electronic, inductive discharge ignition module

mounted on engine crankcase.

● Kill switch (or key switch); grounds module to stop

engine.

Electrical System

KohlerEngines.com 14 690 01 Rev. G

Electronic Ignition Systems Tests

Test Ignition System

1. Make sure spark plug lead is connected to spark plug.

2. Check condition of spark plug. Make sure gap is set to 0.76 mm (0.030 in.).

Condition Possible Cause Conclusion

Spark plug is not receiving ignition

pulse.

Spark Plug Check gap and adjust if necessary;

reinstall plug.

Spark plug in bad condition. Spark Plug Replace plug, set gap, and install.

Test for Spark

NOTE: To maintain engine speeds obtained during cranking, do not remove spark plug.

Test for spark with ignition tester.

1. Disconnect spark plug lead and connect to post terminal of tester. Connect clip to ground, not to spark plug.

2. Turn engine ignition switch to START/RUN position to initiate test.

3. Crank engine to minimum of 500 RPM, and observe tester. Visible and audible sparks should be produced.

4. Release switch to RUN position. Visible and audible sparks should be produced.

Condition Possible Cause Conclusion

Visible and audible sparks are

produced.

Ignition Module Ignition module is OK.

Visible and audible sparks are not

produced.

Ignition Module or

Wiring and Connections

Make sure ignition switch, kill switch

or key switch is in RUN position.

Check all safety and operator

presence control switches (for

example: ywheel brake kill switch)

and other components, including

wiring and connections for accidental

grounding.

If components, wiring, including

terminals are all veried OK, test

ignition module.

Test Ignition Module

1. Disconnect kill lead from terminal on ignition module.

2. Pull retractable starter or crank engine to a minimum of 500 RPM and check for spark.

Condition Possible Cause Conclusion

Visible and audible sparks are

produced.

Ignition System or

Wiring and Connections

Problem is elsewhere in system/

wiring.

Visible and audible sparks are not

produced.

Ignition Module Replace ignition module.

Starter System

14 690 01 Rev. G KohlerEngines.com

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 sufcient 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 ywheel is

rotating, starter pinion and ywheel 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 electric starters or

retractable starters. Inertia drive electric starters are not

serviceable.

XT electric starters use brake switch for an interlock

(on ground). When bail is held down, switch in brake

assembly completes circuit of ground for starter. If there

is a no crank situation, cause could be brake assembly,

battery, key switch, wiring harness, fuse, or starter itself.

RETRACTABLE STARTERS

WARNING

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.

Retractable Starter Components

A Housing B Recoil Bushing

C Recoil Plate D Recoil Spring

E Pulley F Drive Pawl Springs

G Drive Pawl (Dogs) H Pulley Spring

I Drive Plate J Center Screw

K Grommet L Starter Handle

M Starter Rope N

Double Left-Hand

Knot

O Hex Flange Nut

Starter System

KohlerEngines.com 14 690 01 Rev. G

Remove Starter

NOTE: Whenever possible, an impact wrench should be

used to loosen nuts securing retractable starter.

1. Remove nuts securing starter to blower housing.

2. Remove starter assembly.

Rope Replacement

NOTE: Do not allow pulley/spring to unwind. Enlist aid

of a helper if necessary.

Rope can be replaced without complete starter

disassembly.

1. Remove starter assembly from engine.

2. Pull rope out approximately 12 in. and tie a

temporary (slip) knot in it to keep it from retracting

into starter.

3. Pull knot end out of handle, untie knot, and slide

handle off.

4. Hold pulley rmly and untie slipknot. Allow pulley to

rotate slowly as spring tension is released.

5. When all spring tension on starter pulley is released,

remove rope from pulley.

6. Tie a double left-hand knot in one end of new rope.

7. Rotate pulley counterclockwise to pre-tension spring

(approximately 4 full turns of pulley).

8. Continue rotating pulley counterclockwise until rope

hole in pulley is aligned with rope guide bushing of

starter housing.

9. Insert unknotted end of new rope through rope hole

in starter pulley and rope guide bushing of housing.

10. Tie a slipknot approximately 12 in. from free end of

rope. Hold pulley rmly and allow it to rotate slowly

until slipknot reaches guide bushing of housing.

11. Insert starter rope through starter handle and tie a

double, left-hand knot at end of starter rope. Insert

knot into hole in handle.

12. Untie slip knot and pull on starter handle until starter

rope is fully extended. Slowly retract starter rope into

starter assembly. If recoil spring is properly

tensioned, starter rope will retract fully and starter

handle will stop against starter housing.

Pawls (dogs) Replacement

1. Install a clamp to hold pulley in starter housing and

prevent it from rotating.

2. Unscrew center screw and lift off drive plate.

3. Note positions of pawls and pawl springs before

removing. Remove parts from pulley.

4. Install pawl springs and pawls into pawl slots of

pulley. All parts must by dry.

5. Position drive plate over pawls, aligning actuating

slots in place with raised sections on each drive

pawl. Torque center screw to 5-6 N·m (44-54 in. lb.).

6. Remove clamp and pull starter rope out part way to

check operation of pawls.

Install Starter

1. Place starter onto studs protruding from blower

housing. Start nuts onto studs, but do not tighten.

2. Pull starter handle out until pawls engage in drive

cup. Hold handle in this position and torque nuts to 8

N·m (71 in. lb.).

Disassembly/Inspection and Service

14 690 01 Rev. G KohlerEngines.com

WARNING

Before working on engine or equipment, disable engine as

follows: 1) Disconnect spark plug lead(s). 2) Disconnect

negative (–) battery cable from battery.

Accidental Starts can cause severe injury or

death.

Disconnect and ground spark plug lead(s)

before servicing.

External Engine Components

Engine Cover and

Insert

B Engine Cover C

Engine Cover and

Retractable Start

D Retractable Starter

E Blower Housing F Mufer Guard G Mufer H Air Cleaner Base

I Breather Hose J Paper Element K Air Cleaner Cover L Precleaner

Disassembly/Inspection and Service

KohlerEngines.com 14 690 01 Rev. G

Drain Oil From Crankcase Plug (if accessible)

A Crankcase Plug B

Crankcase Plug

(Bottom of Engine)

1. To keep dirt, grass clippings, and other debris out of

engine, clean area around oil ll cap/dipstick, and

then remove it.

2. Remove crankcase plug on bottom of engine.

3. Drain oil into an approved container.

4. Dispose of used oil in accordance with local

ordinances.

Remove Engine Cover Insert (if equipped) and

Cover

NOTE: Whenever possible, an impact wrench should be

used to loosen nuts securing retractable starter.

1. Remove Torx screws securing engine cover insert.

2. Remove nuts securing engine cover. Remove

engine cover.

Remove Engine Cover and Retractable Starter (if

equipped)

NOTE: Whenever possible, an impact wrench should be

used to loosen nuts securing retractable starter.

Remove nuts securing engine cover and retractable

starter. Remove engine cover and retractable starter.

Clean all parts thoroughly as engine is disassembled.

Only clean parts can be accurately inspected

and gauged for wear or damage. There are many

commercially available cleaners that will quickly remove

grease, oil, and grime from engine parts. When such a

cleaner is used, follow manufacturer's instructions and

safety precautions carefully.

Make sure 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

NOTE: Pull on boot only, to prevent damage to spark

plug lead.

Disconnect lead from spark plug.

Empty Fuel Tank

1. Ensure fuel tank is empty by running engine until it

stops, and is completely out of fuel.

2. Remove gas cap.

Drain Oil From Crankcase

Drain Oil from Dipstick Tube

A Air Cleaner B Oil

1. To keep dirt, grass clippings, and other debris out of

engine, clean area around oil ll cap/dipstick.

2. Remove oil ll cap/dipstick.

3. Tilt engine on its side with air cleaner facing up.

Drain oil into an approved container.

4. After crankcase is completely drained, tilt engine

back to level.

5. Dispose of used oil in accordance with local

ordinances.

Disassembly/Inspection and Service

14 690 01 Rev. G KohlerEngines.com

Remove Retractable Starter

Remove screws securing retractable starter assembly to

engine.

Remove Blower Housing

Lift off blower housing and retain stud spacers.

Remove Mufer Assembly

1. Remove nuts securing mufer guard to cylinder

head.

2. Slide mufer off studs.

3. Remove heat deector gasket from exhaust studs,

noting orientation.

Remove Air Cleaner Assembly

1. Loosen knob or unhook latch and remove air cleaner

cover.

2. Remove paper element and foam precleaner (if

equipped).

3. Remove nuts and screw securing air cleaner base to

cylinder head and crankcase.

4. Detach breather hose from crankcase.

5. Remove air cleaner base and detach primer hose

from carburetor (primer bulb equipped models only).

6. Remove air cleaner base gasket from carburetor,

noting orientation.

Carburetor Components

Remove Carburetor with Primer or Carburetor with

Choke (if equipped)

A Carburetor Stud(s) B

Gasket and Spacer

Kit

Gasket and Heat

Shield Kit

D Linkage

E Carburetor

NOTE: Ensure fuel tank is empty by running engine until

it stops, and is completely out of fuel.

1. Squeeze hose clamp and slide it and fuel line off

carburetor.

2. Slide carburetor to end of intake studs.

3. Turn throttle lever clockwise until it stops. Gently

push rod and spring linkages up to disconnect them

from throttle lever.

4. Rotate carburetor until choke linkage can be

disconnected from carburetor. If equipped.

5. Slide off carburetor heat shield, spacer, and gasket,

noting sequence.

Disassembly/Inspection and Service

KohlerEngines.com 14 690 01 Rev. G

Remove Carburetor with Auto Choke (if equipped)

A Nut(s) B Arm Assembly

C Linkage D Choke Linkage

E Governor Linkage F Linkage Spring

G Wire Choke Linkage H Choke Link

1. Remove screws securing arm assembly to

carburetor.

2. Disconnect fuel line.

3. Remove wire choke linkage while sliding carburetor

away from engine a couple of inches.

4. Disconnect governor linkage and linkage spring from

carburetor.

5. Remove carburetor.

6. Remove nuts securing arm assembly to mufer.

Second nut is located behind arm assembly base

securing it to top of mufer.

7. Remove arm assembly from mufer.

Control Components

A Flywheel Brake

Spring

B Speed Control

Bracket

C Linkage Spring D Governor Lever

E Governor Spring F Throttle Linkage

Remove Speed Control Bracket

Disconnect governor spring from speed control bracket.

Remove Speed Control Bracket

NOTE:

Fuel hose connecting carburetor and fuel tank is

held in place by a plastic ring, mounted on back of

speed control bracket. If bracket is removed from

crankcase, it will remain attached to fuel hose (not

including California engines). Should replacement

of speed bracket be required, disconnect fuel line

from fuel lter or carburetor and slide bracket off

hose. Do not disconnect fuel hose from fuel tank.

Remove screws securing speed control bracket.

Disassembly/Inspection and Service

14 690 01 Rev. G KohlerEngines.com

Remove Governor Lever

Loosen governor lever nut and slide lever off governor

shaft.

Flywheel/Ignition/Fuel Tank Components

A Fuel Tank B Crankcase Bracket

C Electric Starter D Ignition Module

E Stud(s) F Drive Cup

G Fan H Flywheel

I Screw(s) J

Flywheel Brake

Assembly

K Breather Assembly

Remove Fuel Tank

1. Ensure fuel tank is empty.

2. Detach fuel tank from crankcase bracket by

removing nut or screw.

3. Remove studs securing top of fuel tank and lift off

tank.

Remove Ignition Module

1. Disconnect kill lead from ignition module.

2. Remove screw and stud securing ignition module.

Mark stud for identication during reassembly.

Disconnect Flywheel Brake Spring

Grasp 1 end of ywheel brake spring with a pliers and

stretch it to disconnect it.

Remove Flywheel

1. Using a ywheel strap wrench to hold ywheel,

remove nut inside drive cup.

2. Remove drive cup and lift off fan, noting orientation

on ywheel for reassembly.

3. Flywheel is mounted on a tapered shaft. To break it

loose, use a rubber mallet to land a rm blow toward

outer rim of ywheel. Remove ywheel.

4. Remove ywheel key from crankshaft.

Inspection

Inspect ywheel for cracks and check keyway for wear

or damage. Replace ywheel if cracked. If ywheel key

is sheared or keyway is damaged, replace crankshaft,

ywheel, and key.

Inspect ring gear for cracks or damage. Ring gears are

not available separately. Replace ywheel if ring gear is

damaged.

Remove Electric Starter (if equipped)

Remove screws securing electric starter to engine.

Remove Breather Assembly

Breather system is designed to control amount of oil

in head area and still maintain necessary vacuum in

crankcase.

When pistons move downward, crankcase gases are

pushed past reed through mesh lter into intake system.

Upward travel of pistons closes reed and creates a

low vacuum in lower crankcase. Any oil separated out

through lter drains back into crankcase.

1. Remove screws securing breather cover. Remove

cover.

2. Remove breather spring, disc and screen.

Remove Spark Plug

Remove spark plug from cylinder head.

Remove Flywheel Brake Assembly

Remove screws securing ywheel brake assembly;

retain spacers (if equipped).

Disassembly/Inspection and Service

KohlerEngines.com 14 690 01 Rev. G

Cylinder Head Components

A Valve Cover B Gasket C Jam Nut D Rocker Arm Pivot

E Rocker Arms F Rocker Arm Stud G Push Rod H Push Rod Guide

Plate

I Valve Keeper J Valve Spring K Intake Valve Seal L Spark Plug

M Bafe N Cylinder Head O Valve P Dowel Pin

Remove Valve Cover

Valve Cover with Gasket

1. Remove screws from valve cover.

2. Remove cover and gasket.

Valve Cover with RTV Sealant

NOTE:

Valve cover is sealed to cylinder head using RTV

silicone sealant. When removing valve cover, use

care not to damage gasket surfaces of cover and

cylinder head. To break RTV seal, hold a block of

wood against 1 at face of valve cover. Strike wood

rmly with a mallet. If seal doesn't break loose after

1 or 2 attempts, repeat procedure on other side.

1. Remove screws securing valve cover.

2. Using a brass wire brush and gasket remover or

similar solvent, clean old RTV from surface of

cylinder head and valve cover.

Remove Jam Nuts and Rocker Arm Pivots

Use a socket and wrench to remove jam nuts and rocker

arm pivots from rocker studs.

Disassembly/Inspection and Service

14 690 01 Rev. G KohlerEngines.com

Valve Details

Dimension Intake Exhaust

A Seat Angle

90° 90°

B Guide Depth 22.6 mm 20.5 mm

C Guide I.D. 5.500/5.512 mm 5.500/5.512 mm

D Valve Head Diameter 25.875/26.125 mm 23.875/24.125 mm

E Valve Face Angle

45° 45°

F Valve Margin (Min.) 0.80 mm 0.80 mm

G Valve Stem Diameter 5.465/5.480 mm 5.465/5.480 mm

Remove Rocker Arms

Noting orientation, lift rocker arms off rocker studs.

Remove Push Rods

Remove push rods and mark them for reinstallation.

Remove Rocker Studs

Unscrew and remove rocker studs from cylinder head.

Remove Guide Plate

1. Remove guide plate from rocker studs.

2. Note orientation of guide plate (tabs down) for use

during reassembly.

Remove Cylinder Head

1. Remove screws securing cylinder head.

2. Remove cylinder head, noting positioning of dowels.

3. Remove head gasket and discard.

Valve Inspection and Service

Carefully inspect valve mechanism parts. Inspect valve

springs and related hardware for excessive wear or

distortion. Check valves and valve seats for evidence

of deep pitting, cracks, or distortion. Following diagram

outlines valve running clearances between valve stems

and guides.

Disassembly/Inspection and Service

KohlerEngines.com 14 690 01 Rev. G

Remove Valve Assembly

NOTE: Only intake valve has a seal. There is no valve

seal on exhaust side.

1. Push down on valve spring keepers to release valve

springs from valve stems.

2. Remove valve spring keepers and springs.

3. Push end of intake valve to release valve seal.

4. Remove both valves from opposite side of head.

Inspection and Service

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 rst. After removal,

clean valve heads, faces, and stems with a power wire

brush. Then, carefully inspect each valve for defects

such as warped head, excessive corrosion, or worn stem

end. Replace valves found to be in bad condition.

Valve Guides

To check valve guide-to-valve stem clearance,

thoroughly clean valve guide and, using a split-ball

gauge, measure inside diameter. Then, using an outside

micrometer, measure diameter of valve stem at several

points on stem where it moves in valve guide. Use

largest stem diameter to calculate clearance. If intake

clearance exceeds 0.047 mm (.0018 in.) or exhaust

clearance exceeds 0.082 mm (.0032 in.), determine

whether valve stem or guide is responsible for excessive

clearance.

Maximum (I.D.) wear on intake valve guide is 5.512 mm

(0.2170 in.), while 5.512 mm (0.2170 in.) is maximum

allowed on exhaust guide. Guides are not removable. If

guides are within limits but valve stems are worn beyond

limits, replace valves.

Valve Seat Inserts

Hardened steel alloy intake and exhaust valve seat

inserts are press tted into cylinder head. Inserts are

not replaceable, but they can be reconditioned if not too

badly pitted or distorted. If seats are cracked or badly

warped, cylinder head should be replaced.

Recondition valve seat inserts following instructions

provided with valve seat cutter (A) being used. Final cut

should be made with an 90° cutter as specied for valve

seat angle. With proper 45° valve face angle, and valve

seat cut properly (44.5° as measured from center line

when cut 90°) this would result in desired 0.5° (1.0° full

cut) interference angle where maximum pressure occurs

on valve face and seat.

Lapping Valves

Reground or new valves must be lapped in, to provide

a good seal. Use a hand valve grinder with suction

cup for nal lapping. Lightly coat valve face with ne

grade of grinding compound, then rotate valve on seat

with grinder. Continue grinding until smooth surface is

obtained on seat and on valve face. Thoroughly clean

cylinder head in soap and hot water to remove all traces

of grinding compound. After drying cylinder head, apply

a light coating of engine oil to prevent rusting.

Disassembly/Inspection and Service

14 690 01 Rev. G KohlerEngines.com

Crankcase Components

A Crankcase Oil Seal B Crankcase C

Governor Cross

Shaft

D Oil Pan Gasket

E Crankcase Bearing F Camshaft G Piston Pin Retainer H Piston Pin

I Piston J Piston Ring Set K Connecting Rod L

Connecting Rod

End Cap

M Crankshaft N Retainer O Governor Shaft P Governor Gear

Q Governor Washer R Governor Cup S Oil Pan T Oil Pan Oil Seal

U Dipstick Tube V Screw

Remove Dipstick Tube (Extended Dipstick)

Remove screw securing dipstick tube. Remove tube.

Remove Oil Pan

NOTE: Some engines have an oil pan gasket; some

engines use RTV to secure oil pan to crankcase.

1. Remove screws securing oil pan.

2. Using a at blade screwdriver as a wedge, carefully

separate oil pan from crankcase.

3. Remove old gasket (if equipped) and discard.

Inspection

Inspect oil seal in oil pan and remove it if it is worn or

damaged.

Disassembly/Inspection and Service

KohlerEngines.com 14 690 01 Rev. G

Remove Camshaft

Remove camshaft from crankcase.

Inspection and Service

Inspect gear teeth of camshaft. If teeth are badly worn

or chipped, or if some are missing, replacement of

camshaft will be necessary. If unusual wear or damage

is evident on either camshaft lobes or mating tappets

camshaft and both tappets must be replaced. Check

condition and operation of Automatic Compression

Release (ACR) mechanism.

ACR

These engines are equipped with an ACR mechanism.

ACR lowers compression at cranking speeds to make

starting easier.

ACR mechanism consists of a decompression weight

and arm mounted to camshaft, and activated by a return

spring. When engine is rotating at low cranking speeds

(1000 RPM or less), decompression weight holds arm

so it protrudes above heel of exhaust lobe. This holds

exhaust valve off its seat during rst part of compression

stroke.

After engine speed increases above approximately 1000

RPM, centrifugal force causes decompression weight

to move outward, causing arm to retract. When in this

position, arm has no effect on exhaust valve and engine

operates at FULL compression and power.

Benets

As a result of reduced compression at cranking speeds,

several important benets are obtained:

1. Manual (retractable) starting is much easier. Without

ACR, manual starting would be virtually impossible.

2. Electric start models can use a smaller starter and

battery which are more practical for application.

3. ACR eliminates need for a spark retard/advance

mechanism. A spark retard/advance mechanism

would be required on engines without ACR to

prevent kickback which would occur during starting.

ACR eliminates this kickback, making manual

starting safer.

4. Choke control setting is less critical with ACR. If

ooding occurs, excess fuel is blown out opened

exhaust valve and does not hamper starting.

5. Engines with ACR start much faster in cold weather

than engines without ACR.

6. Engines with ACR can be started with spark plugs

which are worn or fouled. Engines without ACR are

more difcult to start with those same spark plugs.

Remove Governor Gear and Shaft

1. Remove screw and retainer securing governor gear.

2. Remove hitch pin securing governor shaft. Remove

shaft.

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.

Remove Tappets

Remove tappets. Mark them INTAKE and EXHAUST for

reinstallation.

Remove Connecting Rod Cap

Rotate crankshaft to allow access to 2 screws on

connecting rod cap. Remove screws and cap.

Remove Piston and Connecting Rod

Carefully guide piston and attached connecting rod out

of cylinder bore.

Connecting Rod Inspection and Service

Check bearing area (big end) for excessive wear, score

marks, running and side clearances. Replace connecting

rod and end cap if scored or excessively worn.

Service replacement connecting rods are available in

STD size.

Piston and Rings Inspection

Scufng and scoring of pistons and cylinder walls occurs

when internal engine temperatures approach welding

point of piston. Temperatures high enough to do this are

created by friction, which is usually attributed to improper

lubrication and/or overheating of engine.

Normally, very little wear takes place in piston boss or

piston pin area. If original piston and connecting rod can

be reused after new rings are installed, original pin can

also be reused but new piston pin retainers are required.

Piston pin is included as part of piston assembly – if pin

boss in piston or pin itself is 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 ame fronts, which meet

and explode to create extreme hammering pressures on

a specic 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 such as glowing carbon deposits, blocked

cooling ns, an improperly seated valve, or a wrong

spark plug.

Replacement pistons are available in STD bore size.

Replacement pistons include new piston ring sets and

new piston pins.

Replacement ring sets are also available separately

for STD pistons. Always use new piston rings when

installing pistons. Never use old rings.

Disassembly/Inspection and Service

14 690 01 Rev. G KohlerEngines.com

Some important points to remember when servicing

piston rings:

1. Cylinder bore must be de-glazed before service ring

sets are used.

2. If cylinder bore does not need re-boring and if old

piston is within wear limits and free of score or scuff

marks, old piston may be reused.

3. Remove old rings and clean up grooves. Never

reuse old rings.

4. Before installing new rings on piston, place top 2

rings, each in turn, in its running area in cylinder

bore and check end gap. Compare ring gap to

Clearance Specications.

5. After installing new compression (top and middle)

rings on piston, check piston-to-ring side clearance.

Compare clearance to Clearance Specications. If

side clearance is greater than specied, a new

piston must be used.

Install New Piston Rings

Top Compression

Ring

Middle Compression

Ring

C Oil Control Ring D Top Rail

E Expander Ring F Bottom Rail

Piston Ring Orientation

(≥ 60°)

Oil Ring Expander

Gap

B Bottom Oil Rail Gap

C Top Oil Rail Gap D

Intermediate

Compression

Ring Gap

Top Compression

Ring Gap

NOTE: Rings must be installed correctly. Install oil

control ring assembly (bottom groove) rst,

middle compression ring (center groove)

second, and top compression ring (top groove)

last. Oil control ring assembly is a three-piece

design, and consists of a top rail, expander ring,

and bottom rail.

Use a piston ring expander to install rings.

1. Oil control ring assembly (bottom groove): Install

expander rst then bottom rail and top rail last. Make

sure ends of expander are not overlapped. Adjust

ring gaps.

2. Middle compression ring (center groove): Install

middle compression ring using a piston ring

expander tool. Make sure identication mark is up or

colored dye stripe (if contained) is left of end gap.

Adjust ring gaps.

3. Top compression ring (top groove): Install top

compression ring using a piston ring expander tool.

Make sure identication mark is up or colored dye

stripe (if contained) is left of end gap. Adjust ring

gaps.

Disassembly/Inspection and Service

KohlerEngines.com 14 690 01 Rev. G

Remove Crankshaft

Remove crankshaft.

Inspection and Service

Inspect gear teeth of crankshaft and ACR gear. If any

teeth are badly worn or chipped, or if some are missing,

replacement of crankshaft will be necessary.

Inspect crankshaft bearing surfaces for scoring,

grooving, etc. Measure running clearance between

crankshaft journals and their respective bearing bores.

Use an inside micrometer or telescoping gauge to

measure inside diameter of both bearing bores in vertical

and horizontal planes. Use an outside micrometer to

measure outside diameter of crankshaft main bearing

journals. Subtract journal diameters from their respective

bore diameters to get running clearances. Check results

against values in Specications and Tolerances. If

running clearances are within specication, and there

is no evidence of scoring, grooving, etc., no further

reconditioning is necessary. If bearing surfaces are worn

or damaged, crankcase and/or closure plate will need to

be replaced.

Inspect crankshaft keyway. If worn or chipped,

replacement of crankshaft will be necessary.

Inspect crankpin for score marks or metallic pickup.

Slight score marks can be cleaned with crocus cloth

soaked in oil. If wear limits in Specications are

exceeded, it will be necessary to replace crankshaft.

Crankcase

Inspection and Service

Check all gasket surfaces to make sure they are free of

gasket fragments and deep scratches or nicks.

Check cylinder wall for scoring. In severe cases,

unburned fuel can dissolve lubricating oil off piston and

cylinder wall. Without lubrication, piston rings would

make metal to metal contact with wall, causing scufng

and scoring. Scoring of cylinder wall can also be caused

by localized hot spots from blocked cooling ns or from

inadequate or contaminated lubrication.

Reassembly

14 690 01 Rev. G KohlerEngines.com

Crankcase Components

A Crankcase Oil Seal B Crankcase C

Governor Cross

Shaft

D Oil Pan Gasket

E Crankcase Bearing F Camshaft G Piston Pin Retainer H Piston Pin

I Piston J Piston Ring Set K Connecting Rod L

Connecting Rod

End Cap

M Crankshaft N Retainer O Governor Shaft P Governor Gear

Q Governor Washer R Governor Cup S Oil Pan T Oil Pan Oil Seal

U Dipstick Tube V Screw

NOTE: Make sure engine is assembled using all specied torque values, tightening sequences, and clearances.

Failure to observe specications could cause severe engine wear or damage.

NOTE: Always use new gaskets.

NOTE: Make sure all components have been properly cleaned BEFORE reassembly.

NOTE: Remove all traces of cleaners before engine is reassembled and placed into operation. Even small amounts

of these cleaners can quickly break down lubricating properties of engine oil.

Install Crankshaft

Carefully install crankshaft into crankcase through front seal, and fully seat into place. Rotate crankshaft until journal

for connecting rod is away from cylinder.

Reassembly

KohlerEngines.com 14 690 01 Rev. G

Install Oil Pan

Torque Sequence

XT-7, XTR-7, XT775, XT8

XT-6, XTR-6, XT6.5, XT6.75, XT650, XT675

Install Piston and Connecting Rod

NOTE: Proper orientation of piston and connecting rod

inside engine is extremely important. Improper

orientation can cause extensive wear or

damage.

1. Stagger piston rings in grooves until end gaps are

60° or more apart. Lubricate cylinder bore,

crankshaft journal, connecting rod journal, piston,

and rings with engine oil.

2. Compress piston rings using a piston ring

compressor.

3. Position triangle on top of piston toward push rod

chamber.

4. Carefully guide connecting rod, with piston attached,

into bore.

5. Use handle of a soft, rubber-grip hammer to tap

piston into bore.

6. Rotate crankshaft to mate with connecting rod. Align

rod cap and connecting rod to match marks. Torque

screws to 12.5 N·m (110 in. lb.).

Install Tappets

Install intake and exhaust tappets into their respective

positions, as previously marked.

Install Camshaft

1. Lubricate camshaft and cam gear surfaces with light

grease or oil.

2. Install camshaft and align timing marks.

Install Governor Gear Assembly

NOTE: When installing governor, at of governor shaft

(located on outside of crankcase) should be

turned so at is parallel to crankcase gasket

surface. Paddle of governor shaft (located inside

crankcase) should be pointing away from

crankcase gasket surface.

1. Install governor gear and retainer, and torque screw

to 9.5 N·m (84 in. lb.).

2. Install governor cross shaft and secure it with hitch

pin.

Reassembly

14 690 01 Rev. G KohlerEngines.com

NOTE: When installing oil pan, ensure plunger on

governor gear is pressed fully into governor.

Incorrectly installing governor plunger may result

in damage.

NOTE: Some engines use an oil pan gasket; some

engines use RTV to secure oil pan to crankcase.

1. Sealing surfaces of crankcase and oil pan should be

clean, dry and free of any nicks or burrs.

2. Install 2 crankcase dowels into crankcase.

3. OIL PAN GASKET: Using crankcase dowels as a

guide, install a new oil pan gasket onto crankcase.

RTV: Refer to Tools and Aids for a listing of

approved sealants. Always use fresh sealant. Using

outdated sealant can result in leakage. Using

sealant pattern, apply a 1.5 mm (1/16 in.) bead of

sealant to sealing surface of oil pan.

4. Guide oil pan onto crankcase, ensuring camshaft

and governor gear align with their mating surfaces.

Rotate crankshaft slightly to help engage governor

gear.

5. Install and nger tighten screws, securing oil pan to

crankcase.

6. Use torque sequence shown and torque oil pan

screws to:

Model Torque

XT6, XTR-6

11.0 N·m (98 in. lb.)XT6.5, XT6.75

XT650, XT675

XT-7, XTR-7

14.7 N·m (130 in. lb.)

XT775, XT8

Sealant Pattern

XT775, XT8

XT6.5, XT6.75

A 1.5 mm (1/16 in.) bead of sealant.

Reassembly

KohlerEngines.com 14 690 01 Rev. G

Cylinder Head Components

A Valve Cover B Gasket C Jam Nuts D Rocker Arm Pivot

E Rocker Arms F Rocker Arm Stud G Push Rods H

Push Rod Guide

Plate

I Valve Keeper J Valve Spring K Intake Valve Seal L Spark Plug

M Bafe N Cylinder Head O Valve P Dowel Pin

Install Cylinder Head Assembly

Prior to assembly, lubricate all components with engine oil, including tips of valve stems and valve guides.

Install Valve Train

1. Install intake and exhaust valves into their respective positions in cylinder head.

2. Install intake valve seal onto intake valve. Next, slide valve springs onto both valves and lock them in place with

valve spring keepers.

Reassembly

14 690 01 Rev. G KohlerEngines.com

Install Cylinder Head

Torque Sequence

NOTE: Do not reuse cylinder head gasket. Always

replace with new gasket.

1. Examine sealing surfaces of cylinder head and

crankcase for nicks or burrs.

2. Using cylinder head dowels as a guide, install a new

head gasket.

3. Match sides of head together and nger tighten

screws.

4. Torque screws in two stages; rst to 14 N·m

(123 in. lb.), nally to 27.8 N·m (246 in. lb.), following

sequence shown.

Install Push Rod Assembly

NOTE: Installation and seating of push rods into tappet

recesses during this sequence is critical. To aid

with proper installation of push rods and rocker

arms, and for adjusting valve lash, position

engine with cylinder head up. When properly

installed, push rods extend approximately 1 in.

(25.4 mm) above guide plate.

1. With tabs on guide plate facing down, install rocker

studs.

2. Tighten rocker studs to 13.6 N·m (120 in. lb.).

3. Install push rods into intake and exhaust positions,

as previously marked.

4. Apply grease to contact surfaces of rocker arms and

pivots.

5. Install rocker arms onto rocker studs. Match rocker

arm dimples with round push rod ends.

6. Loosely install pivots and jam nuts onto rocker studs.

7. With piston at top dead center of compression

stroke, insert a 0.1 mm (0.004 in.) at feeler gauge

between 1 valve stem and rocker arm.

Valve Clearance Specications:

Intake Valve 0.0762-0.127 mm (0.003-0.005 in.)

Exhaust Valve 0.0762-0.127 mm (0.003-0.005 in.)

8. Tighten rocker pivot with a wrench until a slight drag

is felt on feeler gauge. Hold nut in position and

tighten jam nut to 9.5 N·m (84 in. lb.). Recheck lash.

Perform same adjustment procedure on opposite

valve.

Install Valve Cover

Torque Sequence

Valve Cover with Gasket

1. Position a new valve cover gasket on cylinder head.

2. Install valve cover and nger tighten screws.

3. Using sequence shown, tighten cover screws to

8 N·m (71 in. lb.).

Valve Cover with RTV

A RTV Sealant

NOTE: Always use fresh sealant. Using outdated

sealant can result in leakage. Refer to Tools and

Aids for important information on sealant

dispenser.

NOTE: To ensure proper adhesion of sealant to both

sealing surfaces, perform step 3 immediately (5

minutes maximum) after application of RTV.

1. Prepare sealing surface of cylinder head and valve

cover.

2. Apply a 1.5 mm (1/16 in.) bead of sealant to valve

cover as shown.

3. Install valve cover and nger tighten screws.

4. Using sequence shown, tighten cover screws to

8 N·m (71 in. lb.).

Reassembly

KohlerEngines.com 14 690 01 Rev. G

Flywheel/Ignition/Fuel Tank Components

A Screws B Fuel Tank

C Crankcase Bracket D Electric Starter

E Ignition Module F Stud(s)

G Drive Cup H Fan

I Flywheel J Screw(s)

Flywheel Brake

Assembly

L Breather Assembly

Install New Spark Plug

1. Set gap of a new spark plug to 0.76 mm (0.03 in.).

2. Install spark plug and torque to 27 N·m (20 ft. lb.).

Install Flywheel Brake Assembly

Dipstick Side of Engine

1. Install spacers onto brake assembly screws.

Fuel Cap Side of Engine

1. Place brake assembly onto engine and loosely

install 2 brake assembly screws.

2. Install a caliper between brake lever and bracket to

establish a 50 mm (1.968 in.) gap, pivoting on rear

screw if necessary.

3. Rotate brake lever clockwise around rear screw.

Torque screws to 9.5 N·m (84 in. lb.). Reinstall kill

lead to ignition module or to bottom terminal on

micro switch (if equipped).

4. Actuate brake arm and verify an audible click is

heard from micro switch (if equipped). Visually

inspect all wires are connected and micro switch is

moving up and down when brake arm is pulled. If an

audible click from micro switch is not heard, loosen

both screws and readjust.

Install Breather Assembly

1. Install breather disc and spring.

2. Install breather screen.

3. Install breather cover and secure with screws.

Torque screws to 10 N·m (88 in. lb.).

Reassembly

14 690 01 Rev. G KohlerEngines.com

Install Flywheel

CAUTION

Damaging Crankshaft and Flywheel can

cause personal injury.

Using improper procedures can lead to broken

fragments. Broken fragments could be thrown from

engine. Always observe and use precautions and

procedures when installing ywheel.

NOTE: Before installing ywheel make sure crankshaft

taper and ywheel hub are clean, dry, and

completely free of lubricants. Presence of

lubricants can cause ywheel to be over

stressed and damaged when mounting nut is

torqued to specication.

NOTE: Make sure ywheel key is installed properly in

keyway. Flywheel can become cracked or

damaged if key is not properly installed.

NOTE: Always use a ywheel strap wrench to hold

ywheel when tightening ywheel fastener. Do

not use any type of bar or wedge to prevent

ywheel from rotating, as these parts could

become cracked or damaged.

1. Install key, into crankshaft keyway. Make sure key is

fully seated.

2. Install ywheel onto crankshaft aligning keyway with

key.

3. Align teardrop slot on fan with raised teardrop on

ywheel. Align drive cup on ywheel, and install and

hand tighten nut.

4. Using a ywheel strap wrench, hold ywheel still

while simultaneously tightening nut to 51.5 N·m

(38 ft. lb.).

Install Electric Starter (if equipped)

Align and mount electric starter onto crankcase. Install

and torque screws to 9.5 N·m (84 in. lb.).

Install Ignition Module

NOTE: If stud for mounting ignition module was not kept

segregated from 2 studs for mounting fuel tank,

compare their lengths and choose short one.

1. Rotate ywheel so ignition magnets are away from

ignition module legs. Position ignition module on

legs with kill tab down.

2. Loosely thread stud and screw into appropriate leg.

Pull module away from ywheel and tighten stud to

hold it in place. Rotate ywheel so ignition magnet is

aligned with module.

3. Set air gap by placing a 0.254 mm (0.010 in.) plastic

feeler gauge between magnet and module. Loosen

stud and let magnet draw module against feeler

gauge. Torque fasteners to 10 N·m (88 in. lb.).

4. Rotate ywheel to release feeler gauge, and check

module does not come in contact with magnet.

Recheck air gap.

5. Connect kill lead to ignition module kill tab.

Install Fuel Tank

1. Secure fuel tank bracket to crankcase by torquing

nut or screw to 8 N·m (71 in. lb.).

2. Secure top of fuel tank to crankcase by installing

threaded studs. Torque studs to 10 N·m (88 in. lb.).

3. Install spacers on studs.

Install Flywheel Brake Spring

A Brake Assembly Screws

Using a pliers, attach ywheel brake spring onto bracket

hook.

Reassembly

KohlerEngines.com 14 690 01 Rev. G

Install Governor Assembly

1. Install governor lever onto governor shaft with lever

up.

2. Attach throttle linkage and linkage spring to top of

governor lever.

Control Components

Flywheel Brake

Spring

Speed Control

Bracket

C Linkage Spring D Governor Lever

E Governor Spring F Throttle Linkage

Speed Bracket Details

Fixed Speed with

Primer (No Choke)

Fixed Speed with

Choke

Variable Speed with

Choke

D Throttle Linkage

E Linkage Spring F Throttle Lever

G Governor Spring H

Speed Control

Bracket

I Governor Lever J Choke Lever

K Choke Linkage L

Dual Throttle Choke

Control

Speed Control

Screw

Install Speed Control Bracket

NOTE: There are 3 different speed bracket variations for

this engine. Images shown identify how different

brackets connect to carburetors with and without

choke.

Reassembly

14 690 01 Rev. G KohlerEngines.com

Loosely attach speed control bracket to crankcase

using shorter screws. Long screw will be used later for

attaching air cleaner body.

Install Governor Spring

Install governor spring between governor lever and

speed control bracket.

Carburetor Components

A Carburetor Stud(s) B

Gasket and Spacer

Kit

Gasket and Heat

Shield Kit

D Linkage

E Carburetor

Install Carburetor Gaskets

Place spacer gasket, cylinder head spacer and heat

deector gasket on carburetor studs in order shown.

Install Carburetor and Linkage

NOTE: There are several different ways to attach

carburetor linkage depending on carburetor and

speed bracket used.

Install Carburetor with Primer (if equipped)

1. With carburetor not yet mounted on studs, rotate it

slightly to allow connection of throttle linkage and

linkage spring to throttle lever.

2. Slide carburetor onto mounting studs.

Install Carburetor with Choke

1. With carburetor not yet mounted on studs, rotate it

slightly and slot elbow, at end of linkage, into choke

lever.

2. Connect throttle linkage and linkage spring to throttle

lever on carburetor.

3. Slide carburetor onto mounting studs.

Auto Choke Components

A Nut(s) B Arm Assembly

C Linkage D Choke Linkage

E Throttle Linkage F Linkage Spring

G Wire Choke Linkage H Choke Link

Reassembly

KohlerEngines.com 14 690 01 Rev. G

Install Carburetor with Auto Choke (if equipped)

1. Mount arm assembly onto mufer securing with nuts. Torque to 8.5 N·m (75 in. lb.).

2. Slide carburetor at least halfway onto mounting studs. Connect throttle linkage and linkage spring to carburetor.

3. Connect wire choke linkage while sliding carburetor to its seated position against engine.

4. Insert screws connecting arm assembly to carburetor. Torque to 2.3 N·m (20 in. lb.).

Adjust Governor

Move governor lever away from carburetor to limit of its travel (wide-open throttle), and hold in this position. Do not

stress, ex or distort linkage. Grasp cross shaft with a pliers and turn shaft clockwise as far as it will go, hold and

tighten nut. Torque nut to 9.5 N·m (84 in. lb.).

Reconnect Fuel Line

Slide fuel line tight up against carburetor, and secure connection with a hose clamp.

External Engine Components

Engine Cover and

Insert

B Engine Cover C

Engine Cover and

Retractable Start

D Retractable Starter

E Blower Housing F Mufer Guard G Mufer H Air Cleaner Base

I Breather Hose J Paper Element K Air Cleaner Cover L Precleaner

Reassembly

14 690 01 Rev. G KohlerEngines.com

Install Air Cleaner Assembly

1. Attach primer hose to carburetor (if equipped).

2. Slide air cleaner gasket onto carburetor studs.

3. Slide air cleaner base onto carburetor studs. Attach

base by loosely screwing nuts onto studs, and screw

into crankcase.

4. Attach breather hose to crankcase.

5. Secure air cleaner base by torquing nuts and screw

to 8 N·m (71 in. lb.).

6. Install paper element and foam precleaner (if

equipped) into air cleaner base. Attach air cleaner

cover and hand tighten knob or secure latch.

Install Dipstick Tube (Extended Dipstick)

1. Install dipstick tube to crankcase.

2. Tighten screw to 8 N·m (71 in. lb.).

Install Mufer Assembly

1. Install heat deector gasket onto exhaust mounting

studs, with gasket folds facing cylinder head.

2. Slide mufer onto exhaust studs.

3. Install mufer guard onto exhaust studs and secure

with nuts. Torque to 9.5 N·m (84 in. lb.).

Install Blower Housing

Install blower housing onto studs.

Install Retractable Starter

Place retractable starter onto studs protruding from

blower housing.

Install Engine Cover

Engine Cover (if equipped)

1. Install engine cover and secure it with nuts.

2. Tighten nuts to 8 N·m (71 in. lb.).

Engine Cover and Insert (if equipped)

1. Install engine cover and secure it with nuts.

2. Tighten nuts to 8 N·m (71 in. lb.).

3. Install engine cover insert (if equipped) onto engine

cover, and secure with Torx screws. Tighten to

2.5 N·m (20 in. lb.).

Engine Cover Insert and Retractable Starter (if

equipped)

1. Install engine cover insert and retractable starter and

secure with nuts.

2. Tighten nuts to 8 N·m (71 in. lb.).

Install Fuel Cap

Screw fuel cap tightly onto fuel tank.

56 KohlerEngines.com 14 690 01 Rev. G