Kohler Command Pro EFI ECH940, Command Pro EFI ECH980 Service Manual

ECH940 & ECH980
Service Manual

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

instruction of equipment that this engine powers.

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

2 Safety
3 Maintenance

5 Specifi cations
21 Tools and Aids
24 Troubleshooting
28 Air Cleaner/Intake
29 Electronic Fuel Injection (EFI) System
53 Governor System
55 Lubrication System
57 Electrical System
63 Starter System
65 Disassembly/Inspection and Service
82 Reassembly

62 690 13 Rev. A 1

KohlerEngines.com

Safety

SAFETY PRECAUTIONS

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

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

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

WARNING

Explosive Fuel can cause
fi res and severe burns.

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

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

WARNING

Rotating Parts can cause
severe injury.

Stay away while engine
is in operation.

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

WARNING

Carbon Monoxide can
cause severe nausea,
fainting or death.

Avoid inhaling exhaust
fumes.

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

Accidental Starts can
cause severe injury or
death.

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

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

Hot Parts can cause
severe burns.

Do not touch engine
while operating or just
after stopping.

Never operate engine with heat
shields or guards removed.

Cleaning Solvents can
cause severe injury or
death.

Use only in well
ventilated areas away
from ignition sources.

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

Electrical Shock can
cause injury.

Do not touch wires while
engine is running.

WARNING

WARNING

WARNING

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 fl ywheel.

Failure to utilize or
reassemble debris
screen as designed could
result in debris screen
failure and serious
personal injury.

High Pressure Fluids can
puncture skin and cause
severe injury or death.

Do not work on fuel
system without proper
training or safety
equipment.

Fluid puncture injuries are highly
toxic and hazardous. If an injury
occurs, seek immediate medical
attention.

Explosive Fuel can
cause fi res and severe
burns.

Fuel system ALWAYS
remains under HIGH
PRESSURE.

Wrap a shop towel completely
around fuel pump module
connector. Press release button(s)
and slowly pull connector away
from fuel pump module allowing
shop towel to absorb any residual
fuel in high pressure fuel line. Any
spilled fuel must be completely
wiped up immediately.

CAUTION

CAUTION

WARNING

WARNING

2 62 690 13 Rev. AKohlerEngines.com

Maintenance

MAINTENANCE INSTRUCTIONS

WARNING

Accidental Starts can cause severe injury or
death.

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

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

MAINTENANCE SCHEDULE

Weekly

● Check fi lter minder. Air Cleaner/Intake

Every 25 Hours or Annually¹

● Service/replace low-profi le precleaner. Air Cleaner/Intake

Every 100 Hours or Annually¹

● Change oil. Oil fi lter is recommended. Lubrication System

● Remove cooling shrouds and clean cooling areas. Air Cleaner/Intake

Every 150 Hours¹

● Check heavy-duty air cleaner element. Air Cleaner/Intake

● Replace low-profi le air cleaner element. Air Cleaner/Intake

● Replace unique Electronic Fuel Injection (EFI) fuel fi lter.

● Check oil cooler fi ns, clean as necessary. Lubrication System

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

Every 200 Hours

● Change oil fi lter. Lubrication System

Every 300 Hours

● Replace heavy-duty air cleaner element and check inner element. Air Cleaner/Intake

Every 500 Hours or Annually¹

● Replace spark plugs and set gap. Electrical System

Every 600 Hours

● Replace heavy-duty inner air cleaner element. Air Cleaner/Intake

1

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

REPAIRS/SERVICE PARTS

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

362 690 13 Rev. A KohlerEngines.com

Maintenance

OIL RECOMMENDATIONS

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

20W-50

10W-30

SAE 30

5W-30

°F -20 020324060

°C -30 -20 -10 0 10 20 30 40

50 80 100

FUEL RECOMMENDATIONS

WARNING

Explosive Fuel can cause fi res and severe
burns.

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

STORAGE

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

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

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

3. Disconnect negative (–) battery cable.

4. Store engine in a clean, dry place.

Gasoline is extremely fl ammable and its vapors can
explode if ignited. Store gasoline only in approved
containers, in well ventilated, unoccupied buildings,
away from sparks or fl 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; eff ects 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 overfi ll fuel tank.

● Do not use gasoline older than 30 days.

4 62 690 13 Rev. AKohlerEngines.com

Engine Dimensions with Heavy-Duty Air Cleaner - Flywheel Side

A

B

AB

C

E

Specifi cations

D

F

H

G

I

Z

Y

X

W

O

P

A 483.0 mm (19.02 in.) B

105.99 mm (4.17 in.)

E

I

M

Q Mounting Hole "A" R 106.0 mm (4.17 in.) S 232.0 mm (9.13 in.) T

U

Y

Lifting Point

130.0 mm (5.12 in.)
Air Filter

Cover Removal

32.22 mm (1.27 in.)

Spark Plug Boot

Engine Mounting

Surface

34.62 mm (1.36 in.)

Spark Plug Removal

AA

J

N

U

T

135.0 mm (5.32 in.)
Rain Cap Cover

Removal

F 136.17 mm (5.36 in.) G 74.03 mm (2.92 in.) H

J Oil Fill K

N 37° O

V Center Line Engine W

69.97 mm (2.76 in.)

Z

Spark Plug Boot

Removal

V

R

S

C 365.5 mm (14.39 in.) D

AA

Q

68.62 mm (2.70 in.)
Spark Plug Boot

Removal

381.05 mm (15.00 in.)
Spark Plug Removal

572.48 mm (22.54 in.)

Lifting Point

Mechanical Fuel

Pump

K

L

M

N

O

AB Lifting Point

P

328.69 mm (12.94

Primary Air Filter

Element Removal

235.39 mm (9.27 in.)
Safety Air Filter

Element Removal

33.28 mm (1.31 in.)

L

Spark Plug Removal

389.59 mm (15.34

P

X

Spark Plug Boot

Removal

8 X Ø 10.7 mm (0.42

Thru Mounting Holes

32.7 mm (1.29 in.)
Spark Plug Boot

in.)

in.)

in.)

562 690 13 Rev. A KohlerEngines.com

Specifi cations

Engine Dimensions with Heavy-Duty Air Cleaner - PTO Side

A

B

Z

F

Y

X

W

C

G

H
F F

D

E

F

I

G

H

J

V

U

T

S

A 428.2 mm (16.86 in.) B 107.9 mm (4.25 in.) C

E

I

M

Q

U Solenoid Shift Starter V

Y

M8 X 1.25 mm

4 Studs

60.0 mm (2.36 in.)
Exhaust Port #2

Ø 142.88 mm
(5.63 in.) B.C.

Ø 177.8 mm

(7.00 in.) Pilot

60.0 mm (2.36 in.)
Exhaust Port #1

F 45° G 35° H 30°

2 X Ø 35.0 mm (1.38 in.)

J

4 X 3/8-16 UNC-2B in.

N

21 mm (0.83 in.) Deep

R 106.0 mm (4.17 in.) S

181.9 mm (7.16 in.)

Z

Gasket

Starter Stud

Oil Level

Dipstick

F

R

W 340.9 mm (13.42 in.) X

F

85.47 mm (3.37 in.)
Lifting Point

K

O

Ø 196.85 mm
(7.75 in.) B.C.

4 X 7/16-14 UNC-2B in.
21 mm (0.83 in.) Deep

68.5 mm (2.70 in.)
Starter Stud

K

L
M

N

O

P

Q

D Lifting Point

L

P

T Mounting Hole "A"

Ø 254.0 mm

(10.0 in.) B.C.

M8 X 1.25 mm-6H in.

25 mm (0.98 in.)

Deep

418.2 mm (16.47 in.)
Lifting Point

6 62 690 13 Rev. AKohlerEngines.com

Engine Dimensions with Heavy-Duty Air Cleaner - Starter Side

A

B

Specifi cations

AA

Z

Y

X

V

W

4 X 47.3 mm (1.86 in.)

A

E 110.7 mm (4.36 in.) F 12.7 mm (0.50 in.) G

I 155.6 mm (6.13 in.) J 113.1 mm (4.45 in.) K 13.88 mm (0.55 in.) L

M

Q 135.0 mm (5.32 in.) R 239.6 mm (9.44 in.) S 401.5 mm (15.81 in.) T

U 435.1 mm (17.13 in.) V Mounting Hole "A" W Grass Screen X

Y 562.7 mm (22.16 in.) Z Cylinder #1 Shroud AA

Air Cleaner Clip

Clearance

Oil Drain Plug

1/2 NPT Inch

B

N 16.0 mm (0.63 in.) O 91.5 mm (3.60 in.) P 119.0 mm (4.69 in.)

50.0 mm (1.97 in.)
Oil Filter Removal

N

O

P

Q

R

S

T

U

C

L

M

105.4 mm (4.15 in.)

38.1 mm (1.5 in.) Deep

45.0 mm (1.77 in.)

Cylinder #1 Shroud

C

D

E

F

G

H

J

K

Exhaust Port #1

5/8-18 UNF-2B in.

Removal

I

58.4 mm (2.30 in.)

D

Center Line Spark

Plug

H

PTO Mounting

Surface

Engine Mounting

Surface

422.8 mm (16.65 in.)
Cylinder #1 Shroud

Removal

181.9 mm (7.16 in.)
Starter Stud

762 690 13 Rev. A KohlerEngines.com

Specifi cations

Engine Dimensions with Heavy-Duty Air Cleaner - Opposite Starter Side

A

B

W

V

U

T

S

Q

C

D

E

F

R

R

Q

P

O

N

81.8 mm (3.22 in.)

A 184.9 mm (7.28 in.) B

E Cylinder #2 Shroud F

I 16.0 mm (0.63 in.) J 91.5 mm (3.60 in.) K 119.0 mm (4.69 in.) L 135.0 mm (5.32 in.)

422.8 mm (16.65 in.)

M

Cylinder #2 Shroud

Removal

Q

U Lifting Point V

PTO Mounting

Surface

Center Line Spark

Plug

Access to
Oil Cooler

N

R Pilot Surface S 696.3 mm (27.41 in.) T Oil Pressure Switch

Engine Mounting

Surface

4 X 20.6 mm

(0.81in.)

Muffl er Mounting Stud

Height

I

J

K

L

M

C

G Mounting Hole "A" H

O 13.88 mm (0.55 in.) P

W

G
H

84.0 mm (3.31 in.)
Oil Filter

82.4 mm (3.24 in.)

Exhaust Port #2

45.6 mm (1.80 in.)

D

Cylinder #2 Shroud

Removal

Oil Drain Plug

1/2 NPT Inch

4 X 4.0 mm (0.16 in.)

Pilot Height

8 62 690 13 Rev. AKohlerEngines.com

Engine Dimensions with Low-Profi le Air Cleaner - Flywheel Side

A

B

C

W

V

U

X

Specifi cations

D

E

F

G

H

I

J

K

T

M

L

S
R

A 483.0 mm (19.02 in.) B 370.9 mm (14.60 in.) C Lifting Point D

E 79.5 mm (3.13 in.) F 136.2 mm (5.36 in.) G

33.3 mm (1.31 in.)

I

Spark Plug Removal

381.1 mm (15.00 in.)

M

Spark Plug Removal

Q Center Line Engine R

32.7 mm (1.29 in.)

U

Spark Plug Boot

J

N Mounting Hole "A" O 106.0 mm (4.17 in.) P 232.0 mm (9.13 in.)

V

32.2 mm (1.27 in.)
Spark Plug Boot

8 X Ø 10.7 mm (0.42 in.)

Thru Mounting Holes

34.6 mm (1.36 in.)

Spark Plug Removal

Q

O

P

68.6 mm (2.70 in.)
Spark Plug Boot

K 37° L

Engine Mounting

S

70.0 mm (2.76 in.)

W

Spark Plug Boot

N

Removal

Surface

Removal

K

M

106.0 mm (4.17 in.)
Lifting Point

H Oil Fill

389.6 mm (15.34 in.)
Spark Plug Boot

Removal

572.5 mm (22.54 in.)

T

X

Lifting Point

Mechanical Fuel

Pump

L

962 690 13 Rev. A KohlerEngines.com

Specifi cations

Engine Dimensions with Low-Profi le Air Cleaner - PTO Side

A

B

C

D

E

F

G

G

J

Z

H

I

Y

G

H

I

K

G

X

G

G

W

V

U

T

S

A 428.2 mm (16.86 in.) B 107.9 mm (4.25 in.) C

E Oil Level Dipstick F

I 30° J

M

Q

Ø 254.0 mm

(10.0 in.) B.C.

4 X M8 X 1.25 mm-6H in.

25 mm (0.98 in.) Deep

N

R

M8 X 1.25 mm 4

Studs

60.0 mm (2.37 in.)
Exhaust Port #2

Ø 142.9 mm

(5.63 in.) B.C.

Ø 177.8 mm

(7.00 in.) Pilot

G 45° H 35°

K

O

U Mounting Hole "A" V Solenoid Shift Starter W

418.2 mm (16.47 in.)

Y

Lifting Point

Z

60.0 mm (2.36 in.)
Exhaust Port #1

Q

R

85.5 mm (3.37 in.)
Lifting Point

2 X Ø 35.0 mm (1.38 in.)

Gasket

4 X 3/8-16 UNC-2B in.
21 mm (0.83 in.) Deep

S 106.0 mm (4.17 in.) T

181.9 mm (7.16 in.)
Starter Stud

L

M

N

O

P

D Lifting Point

L

P

Ø 196.85 mm
(7.75 in.) B.C.

4 X 7/16-14 UNC-2B in.

21 mm (0.83 in.) Deep

68.5 mm (2.70 in.)
Starter Stud

X 340.9 mm (13.42 in.)

10 62 690 13 Rev. AKohlerEngines.com

Engine Dimensions with Low-Profi le Air Cleaner - Starter Side

A

B

Specifi cations

C

D

E

F

O

G

P

N

M

L

J

I

R

Q

K

Z

AA

Y

X

W

V

U

S

T

A 130.4 mm (5.13 in.) B

E 562.7 mm (22.16 in.) F

422.8 mm (16.65 in.)

I

Cylinder #1 Shroud

Removal

M 119.0 mm (4.69 in.) N 91.5 mm (3.6 in.) O Mounting Hole "A" P 16.0 mm (0.63 in.)

Q

U 113.1 mm (4.45 in.) V

Y 110.7 mm (4.36 in.) Z

Oil Drain Plug

1/2 NPT Inch

J 401.5 mm (15.81 in.) K 239.6 mm (9.44 in.) L 135.0 mm (5.32 in.)

R

H

50.0 mm (1.97 in.)
Oil Filter Removal

181.9 mm (7.16 in.)
Starter Stud

Engine Mounting

Surface

PTO Mounting

Surface

58.4 mm (2.30 in.)
Center Line

Spark Plug

45.0 mm (1.77 in.)

C Cylinder #1 Shroud D

G Grass Screen H 435.13 mm (17.13 in.)

S 13.88 mm (0.55 in.) T 155.6 mm (6.13 in.)

W

AA

5/8-18 UNF-2B in.

38.1 mm (1.5 in.) Deep

105.4 mm (4.15 in.)
Exhaust Port #1

Cylinder #1 Shroud

Removal

X 12.7 mm (0.50 in.)

1162 690 13 Rev. A KohlerEngines.com

Specifi cations

Engine Dimensions with Low-Profi le Air Cleaner - Opposite Starter Side

A

B

Y

W

X

V

U

T

R

S

S

R

Q

O

P

C

N

M

L

K

D

E

F

G

H

I

J

A 184.9 mm (7.28 in.) B 130.4 mm (5.13 in.) C

45.6 mm (1.80 in.)

E

Cylinder #2 Shroud

Removal

I 16.0 mm (0.63 in.) J

M 91.5 mm (3.60 in.) N

4 X 4.0 mm (0.16 in.)

Q

U Oil Pressure Switch V Lifting Point W

Y

12 62 690 13 Rev. AKohlerEngines.com

Pilot Height

67.0 mm (2.64 in.)
Air Cleaner

Cover Removal

F Cylinder #2 Shroud G

422.8 mm (16.65 in.)
Cylinder #2 Shroud

Removal

Oil Drain Plug

1/2 NPT Inch

R

PTO Mounting

Surface

Access to Integrated

K 135.0 mm (5.32 in.) L 119.0 mm (4.69 in.)

O

S Pilot Surface T 597.5 mm (23.52 in.)

81.8 mm (3.22 in.)
Center Line Spark

Plug

Oil Cooler

Engine Mounting

Surface

82.4 mm (3.24 in.)

Exhaust Port #2

84.0 mm (3.31 in.)

D

H Mounting Hole "A"

P 13.88 mm (0.55 in.)

X

Oil Filter

4 X 20.6 mm (0.81

in.)

Muffl er Mounting

Stud Height

Specifi cations

ENGINE IDENTIFICATION NUMBERS

Kohler engine identifi cation numbers (model, specifi cation and serial) should be referenced for effi cient repair,
ordering correct parts, and engine replacement.

Model . . . . . . . . . . . . . . . . . . . . . ECH940

EFI Command Engine

Horizontal Shaft

Numerical Designation

Specifi cation . . . . . . . . . . . . . . . ECH940-0001

Serial . . . . . . . . . . . . . . . . . . . . . 4623500328

Year Manufactured Code Factory Code
Code Year
46 2016
47 2017
48 2018

GENERAL SPECIFICATIONS

2,3

ECH940 ECH980

Bore 90 mm (3.54 in.)
Stroke 78.5 mm (3.1 in.)
Displacement 999 cc (61 cu. in.)
Oil Capacity (refi ll) 1.9-2.6 L (2.0-2.7 U.S. qt.)
Maximum Angle of Operation (@ full oil level)

TORQUE SEQUENCES

4

ECH940 ECH980

25°

(Refer to Torque Specifi cations for torque values).

Backing Shroud Fasteners

1

3

1

2

4

3

Breather Cover Fasteners

2

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

3

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

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

4

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

4

2

1362 690 13 Rev. A KohlerEngines.com

Specifi cations

TORQUE SEQUENCES

(Refer to Torque Specifi cations for torque values).

Cylinder Head Bolt Fasteners

Intake Manifold Mounting Fasteners

ECH940 ECH980

2

4

31

#1

3

1

5

12

5

14

9

2

4

1

3

#2

4

2

Closure Plate Fasteners

Oil Reservoir Fasteners

5

1

3

7

10

8

3

5

13

1

2

8

4

2

6

11

6

4

7

14 62 690 13 Rev. AKohlerEngines.com

Specifi cations

TORQUE SPECIFICATIONS

2,5

ECH940 ECH980

Backing Shroud (torque sequence on page 13)

Backing Shroud to Crankcase 10.7 N·m (95 in. lb.) into new holes

7.3 N·m (65 in. lb.) into used holes

Blower Housing and Sheet Metal

M6 Screw
New, Untapped Hole (casting)
Used, Tapped Hole (casting)
New, Extruded Hole (sheet metal)
Used, Extruded Hole (sheet metal)
Mounting Clip (valley baffl e)

10.7 N·m (95 in. lb.)

7.3 N·m (65 in. lb.)

2.5 N·m (22 in. lb.)

2.0 N·m (18 in. lb.)

2.5 N·m (22 in. lb.)

Closure Plate (torque sequence on page 14)

Closure Plate Fastener 25.6 N·m (227 in. lb.)

Connecting Rod

Cap Fastener (torque in increments) 11.6 N·m (103 in. lb.)

Control Bracket

Mounting Screw (into baffl e) 10.2 N·m (90 in. lb.)

Control Panel

Key Switch to Control Panel Nut 1.6 N·m (14 in. lb.)
Mounting Screw (into intake manifold) 11.3 N·m (100 in. lb.)
Mounting Screw (into oil fi lter housing) 11.3 N·m (100 in. lb.)

Crankcase

Breather Cover Fastener (torque sequence on page 13) 12.4 N·m (110 in. lb.)
Engine (oil) Temperature Sensor 7.3 N·m (65 in. lb.)
Oil Sentry

TM

10.7 N·m (95 in. lb.)

Oil Drain Plug 21.4 N·m (16 ft. lb.)

Cylinder Head (torque sequence on page 14)

Cylinder Head Fastener (torque in 2 increments)
Head Bolt fi rst to 23.7 N·m (210 in. lb.)

fi nally to 46.9 N·m (415 in. lb.)
Pipe Plug (3/4 in.) 28.5 N·m (252 in. lb.)
Rocker Arm Screw 15.5 N·m (137 in. lb.)

Debris Screen/Fan/Flywheel

Debris Screen Fastener 9.9 N·m (88 in. lb.)
Flywheel Retaining Screw 69.8 N·m (51 ft. lb.)
Front Drive Shaft Fastener 24.4 N·m (216 in. lb.)

Fuel Pump Module

Fuel Pump Module Baffl e Fastener 11.3 N·m (100 in. lb.)
Fuel Pump Module Fastener 9.2 N·m (81 in. lb.)

2

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

5

Lubricate threads with engine oil prior to assembly.

1562 690 13 Rev. A KohlerEngines.com

Specifi cations

TORQUE SPECIFICATIONS

2,5

ECH940 ECH980

Fuse Holder Bracket

Fuse Holder Bracket to Cylinder Head Fastener 10.7 N·m (95 in. lb.) into new holes

7.3 N·m (65 in. lb.) into used holes

Governor

Governor Lever Nut 7.1 N·m (63 in. lb.)
Governor Yoke Mounting Screw 2.2 N·m (20 in. lb.)

Ignition

Ignition Coil Fastener 5.1 N·m (45 in. lb.)
Electronic Control Unit Isolation Mount Nut 2.0 N·m (18 in. lb.)
Crankshaft Position Sensor to Bracket Screw 11.3 N·m (100 in. lb.)
Crankshaft Position Sensor Bracket to Crankcase Screw 9.9 N·m (88 in. lb.)
Spark Plug 27 N·m (20 ft. lb.)
Rectifi er-Regulator Fastener 2.5 N·m (22 in. lb.)
Rectifi er-Regulator Ground Lead Fastener to Ground Lug/Backing

Shroud

5.6 N·m (50 in. lb.) into new holes

4.0 N·m (35 in. lb.) into used holes

Wire Harness Clamp and Ground Eyelets Fastener 2.5 N·m (22 in. lb.) into new holes

2.0 N·m (18 in. lb.) into used holes

Intake Manifold (torque sequence on page 14)

Intake Manifold to Cylinder Head Mounting Fastener
(torque in 2 increments)

fi rst to 16.9 N·m (150 in. lb.)

fi nally to 22.6 N·m (200 in. lb.)
Temperature/Manifold Absolute Pressure (TMAP) Sensor Fastener 7.3 N·m (65 in. lb.)
Air Cleaner to Throttle Body Fastener Nut 8.2 N·m (73 in. lb.)
Air Cleaner to Control Bracket Fastener 11.3 N·m (100 in. lb.)
Fuel Injector Cap Fastener 7.3 N·m (65 in. lb.)

Lifter Feed Chamber

Cover Screw 7.7 N·m (68 in. lb.)

Muffl er

Oxygen Sensor 50.1 N·m (37 ft. lb.)
Retaining Nut 24.4 N·m (216 in. lb.)
M6 Screw 9.9 N·m (88 in. lb.)
M8 Screw 24.4 N·m (216 in. lb.)

Oil Cooler

Mounting Screws 2.3 N·m (21 in. lb.)

Oil Filter Housing Assembly

Housing Assembly Mounting Screw 23.7 N·m (210 in. lb.)
Oil Filter Nipple 17.8 N·m (158 in. lb.)

Oil Pickup Screen

Mounting Screw 9.3 N·m (82 in. lb.) into new holes

7.7 N·m (68 in. lb.) into used holes

Oil Pickup Tube

Mounting Screw 11.3 N·m (100 in. lb.) into new holes

7.7 N·m (68 in. lb.) into used holes

2

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

5

Lubricate threads with engine oil prior to assembly.

16 62 690 13 Rev. AKohlerEngines.com

Specifi cations

TORQUE SPECIFICATIONS

2,5

ECH940 ECH980

Oil Pump

Mounting Screw 9.9 N·m (88 in. lb.)

Reservoir (oil) (torque sequence on page 14)

Mounting Screw 25.6 N·m (227 in. lb.)

Starter Assembly

Mounting Screw 16.0 N·m (142 in. lb.)

Stator

Mounting Screw 9.3 N·m (82 in. lb.)

Valve Cover

Valve Cover Fastener 13.6 N·m (120 in. lb.)

CLEARANCE SPECIFICATIONS

2

ECH940 ECH980

Camshaft

End Play 0.3/1.3 mm (0.011/0.051 in.)
Running Clearance 0.025/0.063 mm (0.0010/0.0025 in.)
Bore I.D.

New
Max. Wear Limit

20.000/20.025 mm (0.7874/0.7884 in.)

20.038 mm (0.7889 in.)

Bearing Surface O.D.
New
Max. Wear Limit

19.962/19.975 mm (0.7859/0.7864 in.)

19.959 mm (0.7858 in.)

Cam Lobe Profi le (minimum dimension, measured from base circle
to top of lobe)
Exhaust 35 mm (1.3779 in.)

Intake 35 mm (1.3779 in.)

Connecting Rod

Crankpin End I.D. @ 70°F
New
Max. Wear Limit

44.030/44.037 mm (1.7334/1.7337 in.)

0.070 mm (0.0028 in.)

Connecting Rod-to-Crankpin Running Clearance
New
Max. Wear Limit

0.030/0.055 mm (0.0012/0.0022 in.)

0.070 mm (0.0028 in.)
Connecting Rod-to-Crankpin Side Clearance 0.30/0.59 mm (0.0118/0.0232 in.)
Connecting Rod-to-Piston Pin Running Clearance 0.015/0.028 mm (0.0006/0.0011 in.)
Piston Pin End I.D. @ 70°F

New
Max. Wear Limit

19.023/19.015 mm (0.7489/0.7486 in.)

19.036 mm (0.7494 in.)

Crankcase

Governor Cross Shaft Bore I.D.
New
Max. Wear Limit

2

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

5

Lubricate threads with engine oil prior to assembly.

8.025/8.050 mm (0.3159/0.3169 in.)

8.088 mm (0.3184 in.)

1762 690 13 Rev. A KohlerEngines.com

Specifi cations

CLEARANCE SPECIFICATIONS

2

ECH940 ECH980

Crankshaft

End Play (free)
Non-Thrust Bearing 0.20/0.94 mm (0.008/0.037 in.)

Crankshaft Bore (in crankcase)
New, Without Main Bearing
With Main Bearing Installed
Max. Wear Limit

50.00/50.025 mm (1.9685/1.969 in.)

45.040/45.145 mm (1.7732/1.7773 in.)

45.158 mm (1.7778 in.)

Crankshaft to Sleeve Bearing (in crankcase) Running Clearance
New 0.040/0.167 mm (0.0015/0.0065 in.)

Crankshaft Bore (in closure plate)
New, Without Bearing 50.025/50.00 mm (1.9694/1.9685 in.)

Crankshaft to Sleeve Bearing (in closure plate) Running Clearance
New 0.040/0.167 mm (0.0015/0.0065 in.)

Closure Plate End Main Bearing Journal
O.D. - New
O.D. - Max. Wear Limit
Max. Taper
Max. Out-of-Round

44.978/45.00 mm (1.770/1.771 in.)

44.90 mm (1.767 in.)

0.022 mm (0.0009 in.)

0.025 mm (0.0010 in.)

Connecting Rod Journal
O.D. - New
O.D. - Max. Wear Limit
Max. Taper
Max. Out-of-Round
Width

43.982/44.000 mm (1.731/1.732 in.)

43.97 mm (1.731 in.)

0.018 mm (0.0007 in.)

0.025 mm (0.0010 in.)

53.00/53.09 mm (2.0866/2.0901 in.)

Crankshaft T.I.R.
PTO End, Crank in Engine
Entire Crank, in V-Blocks

0.279 mm (0.0110 in.)

0.10 mm (0.0039 in.)

Flywheel End Main Bearing Journal
O.D. - New
O.D. - Max. Wear Limit
Max. Taper
Max. Out-of-Round

44.978/45.00 mm (1.770/1.771 in.)

44.90 mm (1.767 in.)

0.022 mm (0.0009 in.)

0.025 mm (0.0010 in.)

Cylinder Bore

Cylinder Bore I.D.
New
Max. Wear Limit
Max. Taper
Max. Out-of-Round

90.000/90.025 mm (3.543/3.544 in.)

90.075 mm (3.546 in.)

0.013 mm (0.00051 in.)

0.013 mm (0.00051 in.)

Cylinder Head

Max. Out-of-Flatness 0.076 mm (0.003 in.)

Governor

Governor Cross Shaft-to-Crankcase Running Clearance 0.025/0.087 mm (0.0009/0.0034 in.)
Governor Cross Shaft O.D.

New
Max. Wear Limit

7.963/8.000 mm (0.3135/0.3149 in.)

7.936 mm (0.3124 in.)
Governor Gear Shaft-to-Governor Gear Running Clearance 0.070/0.160 mm (0.0027/0.0063 in.)
Governor Gear Shaft O.D.

New
Max. Wear Limit

2

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

5.990/6.000 mm (0.2358/0.2362 in.)

5.977 mm (0.2353 in.)

18 62 690 13 Rev. AKohlerEngines.com

Specifi cations

CLEARANCE SPECIFICATIONS

2

ECH940 ECH980

Ignition

Spark Plug Gap 0.76 mm (0.030 in.)

Crankshaft Bearing (fl ywheel/PTO)

New (installed)
Max. Wear Limit

45.040/45.145 mm (1.773/1.777 in.)

45.158 mm

Piston, Piston Rings, and Piston Pin
Piston-to-Piston Pin Running Clearance 0.006/0.017 mm (0.0002/0.0007 in.)
Piston Pin Bore I.D.

New
Max. Wear Limit

20.006/20.012 mm (0.7876/0.7879 in.)

20.025 mm (0.7884 in.)

Piston Pin O.D.
New
Max. Wear Limit

19.995/20.000 mm (0.7872/0.7874 in.)

19.994 mm (0.7872 in.)
Top Compression Ring-to-Groove Side Clearance 0.030/0.070 mm (0.001/0.0026 in.)
Middle Compression Ring-to-Groove Side Clearance 0.030/0.070 mm (0.001/0.0026 in.)
Oil Control Ring-to-Groove Side Clearance 0.060/0.190 mm (0.0022/0.0073 in.)
Top Compression Ring End Gap

New
Max. Wear Limit

0.125/0.304 mm (0.0049/0.0120 in.)

0.515 mm (0.0203 in.)

Middle Compression Ring End Gap
New
Max. Wear Limit

Piston Thrust Face O.D.
New Bore
Used Bore (max.)

6

0.900/1.179 mm (0.0354/0.0464 in.)

1.432 mm (0.0564 in.)

89.972 mm (3.5422 in.)

89.827 mm (3.5365 in.)
Piston Thrust Face-to-Cylinder Bore6 Running Clearance

New 0.021/0.060 mm (0.0008/0.00236 in.)

Valves and Valve Lifters

Hydraulic Valve Lifter to Crankcase Running Clearance 0.012/0.050 mm (0.0004/0.0019 in.)
Intake Valve Stem-to-Valve Guide Running Clearance 0.038/0.076 mm (0.0015/0.0030 in.)
Exhaust Valve Stem-to-Valve Guide Running Clearance 0.050/0.088 mm (0.0020/0.0035 in.)
Intake Valve Guide I.D.

New
Max. Wear Limit

7.038/7.058 mm (0.2771/0.2779 in.)

7.135 mm (0.2809 in.)

Exhaust Valve Guide I.D.
New
Max. Wear Limit

7.038/7.058 mm (0.2771/0.2779 in.)

7.159 mm (0.2819 in.)

Valve Guide Reamer Size
Standard

0.25 mm O.S.

7.048 mm (0.2775 in.)

7.298 mm (0.2873 in.)

Nominal Valve Face Angle 45°

2

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

6

Measure 11 mm (0.4331 in.) above bottom of piston skirt at right angles to piston pin.

1962 690 13 Rev. A KohlerEngines.com

Specifi cations

GENERAL TORQUE VALUES

English Fastener Torque Recommendations for Standard Applications

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

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) —

Grade 2 or 5 Fasteners

Into Aluminum

Metric Fastener Torque Recommendations for Standard Applications

Size

4.8

5.8

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)

20 62 690 13 Rev. AKohlerEngines.com

Property Class

8.8

10.9 12.9

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

Noncritical

Fasteners

Into Aluminum

Tools and Aids

Certain quality tools are designed to help you perform specifi c disassembly, repair, and reassembly procedures. By
using these tools, you can properly service engines easier, faster, and safer! In addition, you’ll increase your service
capabilities and customer satisfaction by decreasing engine downtime.

Here is a list of tools and their source.

SEPARATE TOOL SUPPLIERS

Kohler Tools
Contact your local Kohler source of
supply.

TOOLS

Description Source/Part No.

Alcohol Content Tester

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

Camshaft Endplay Plate

For checking camshaft endplay.

Camshaft Seal Protector (Aegis)

For protecting seal during camshaft installation.

Cylinder Leakdown Tester

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

Dealer Tool Kit (Domestic)

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

Dealer Tool Kit (International)

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

Digital Vacuum/Pressure Tester

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

Electronic Fuel Injection (EFI) Diagnostic Software

For Laptop or Desktop PC.

EFI Service Kit

For troubleshooting and setting up an EFI engine.
Components of 24 761 01-S
Fuel Pressure Tester
Noid Light
90° Adapter
Code Plug, Red Wire
Code Plug, Blue Wire
Shrader Valve Adapter Hose
Wire Probe Set (2 pieces regular wire with clip; 1 piece fused wire)
Hose Removal Tool, Dual Size/End (also sold as individual Kohler tool)

Flywheel Puller

For properly removing fl ywheel from engine.

SE Tools
415 Howard St.
Lapeer, MI 48446
Phone [phone]
Toll Free 800-664-2981
Fax [phone]

Design Technology Inc.
768 Burr Oak Drive
Westmont, IL 60559
Phone [phone]
Fax [phone]

Kohler 25 455 11-S

SE Tools KLR-82405

SE Tools KLR-82417

Kohler 25 761 05-S

Design Technology Inc.

DTI-731-03

Kohler 25 761 39-S

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

Kohler 25 761 42-S

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

Design Technology Inc.

DTI-721-01

Design Technology Inc.

DTI-721-10

Kohler 25 761 23-S

Kohler 24 761 01-S

Design Technology Inc.

DTI-019
DTI-021
DTI-023
DTI-027
DTI-029
DTI-037
DTI-031
DTI-033

SE Tools KLR-82408

2162 690 13 Rev. A KohlerEngines.com

Tools and Aids

TOOLS

Description Source/Part No.

Hose Removal Tool, Dual Size/End (also available in EFI Service Kit)

Used to properly remove fuel hose from engine components.

Hydraulic Valve Lifter Tool

For removing and installing hydraulic lifters.

Ignition System Tester

For testing output on all systems, including CD.

Inductive Tachometer (Digital)

For checking operating speed (RPM) of an engine.

Off set Wrench (K and M Series)

For removing and reinstalling cylinder barrel retaining nuts.

Oil Pressure Test Kit

For testing/verifying oil pressure on pressure lubricated engines.

Rectifi er-Regulator Tester (120 volt current)
Rectifi er-Regulator Tester (240 volt current)

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

Spark Advance Module (SAM) Tester

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

.

™

Starter Servicing Kit (All Starters)

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

Triad/OHC Timing Tool Set

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

Valve Guide Reamer (K and M Series)

For properly sizing valve guides after installation.

Valve Guide Reamer O.S. (Command Series)

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

Reamer Handle

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

Kohler 25 455 20-S

Kohler 25 761 38-S

Kohler 25 455 01-S

Design Technology Inc.

DTI-110

Kohler 52 455 04-S

Kohler 25 761 06-S

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

Design Technology Inc.

DTI-031R
DTI-033R

Kohler 25 761 40-S

SE Tools KLR-82411

SE Tools KLR-82416

Kohler 28 761 01-S

Design Technology Inc.

DTI-K828

Kohler 25 455 12-S

Design Technology Inc.

DTI-K830

AIDS
Description Source/Part No.

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

®

51360

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

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

®

5900® Heavy Body in 4 oz. aerosol dispenser.

for use. Permatex® the Right Stuff ® 1 Minute Gasket™ or 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™
Permatex® the Right Stuff ® 1

Minute Gasket™

Spline Drive Lubricant Kohler 25 357 12-S

22 62 690 13 Rev. AKohlerEngines.com

®

Tools and Aids

FLYWHEEL HOLDING TOOL ROCKER ARM/CRANKSHAFT TOOL

A fl ywheel holding tool can be made out of an old junk
fl 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 fl ywheel ring
gear teeth. Bosses will lock tool and fl 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
fl at.

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

4. Use a fl 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.

2362 690 13 Rev. A KohlerEngines.com

Troubleshooting

TROUBLESHOOTING GUIDE

When troubles occur, be sure to check simple causes which, at fi 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 EFI engine troubles are listed below and vary by engine specifi cation. Use these to
locate causing factors.

Engine Cranks But Will Not Start

● Battery connected backwards.

● Blown fuses.

● Clogged fuel line or fuel fi lter.

● Empty fuel tank.

● Faulty ignition coil(s).

● Faulty spark plug(s).

● Fuel pump malfunction-vacuum hose clogged or
leaking.

● Fuel shut-off valve closed.

● Insuffi 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).

● Spark plug lead(s) disconnected.

Engine Starts But Does Not Keep Running

● Faulty cylinder head gasket.

● Faulty or misadjusted 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 fi lter.

● Engine overheated.

● Faulty ACR mechanism (Recoil Start).

● Faulty spark plug(s).

● Flywheel key sheared.

● Fuel pump malfunction-vacuum hose clogged or
leaking.

● Interlock switch is engaged or faulty.

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

● Low compression.

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

● Weak spark.

Engine Will Not Crank

● Battery is discharged.

● Faulty electric starter or solenoid.

● Faulty key switch or ignition switch.

● Interlock switch is engaged or faulty.

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

● Pawls not engaging in drive cup (Recoil Start).

● Seized internal engine components.

Engine Runs But Misses

● Fuel system issue (Fuel Injectors).

● Engine overheated.

● Faulty spark plug(s).

● Ignition module(s) faulty.

● 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 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.

● High crankcase oil level.

● Lean fuel mixture.

● Low crankcase oil level.

● Cooling system components clogged or restricted.

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).

● Loose/worn pulley/clutch on crankshaft PTO.

24 62 690 13 Rev. AKohlerEngines.com

Troubleshooting

Engine Loses Power

● Dirty air cleaner element.

● Engine overheated.

● Excessive engine load.

● Restricted exhaust.

● Faulty spark plug(s).

● High crankcase oil level.

● Incorrect governor setting.

● Low battery.

● Low compression.

● Low crankcase oil level.

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

Engine Uses Excessive Amount of Oil

● Loose or improperly torqued fasteners.

● Blown head gasket/overheated.

● Breather reed broken.

● Clogged, broken, or inoperative crankcase breather.

● Crankcase overfi 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 fi 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 fi t and seal.

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

● Check throttle body 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 fl 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
fl 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.

2562 690 13 Rev. A KohlerEngines.com

Troubleshooting

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.

A partial vacuum should be present in crankcase when engine is operating. Pressure in crankcase (normally caused
by a clogged or improperly assembled breather) can cause oil to be forced out at oil seals, gaskets, or other available
spots.

Crankcase vacuum is best measured with either a water manometer or a vacuum gauge. Complete instructions are
provided in kits.

To test crankcase vacuum with manometer:

1. Insert rubber stopper into oil fi 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 specifi ed (low/no

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

4. Close pinch clamp before stopping engine.

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

To test crankcase vacuum with vacuum/pressure gauge:

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

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

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

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

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

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

vacuum, and movement to right indicates a pressure.

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

WARNING

Condition Conclusion

Crankcase breather clogged or inoperative. NOTE: If breather is integral part of valve cover and

cannot be serviced separately, replace valve
cover and recheck pressure.

Disassemble breather, clean parts thoroughly, check
sealing surfaces for fl atness, reassemble, and recheck
pressure.

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

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

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

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

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

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

26 62 690 13 Rev. AKohlerEngines.com

Troubleshooting

COMPRESSION TEST

For Command Twins:
A compression test is best performed on a warm engine. Clean any dirt or debris away from base of spark plug(s)

before removing them. Be sure choke is off , and throttle is wide open during test. Compression should be at least 160
psi and should not vary more than 15% between cylinders.

All other models:
These engines are equipped with an automatic compression release (ACR) mechanism. It is diffi 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 fi 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 fl ywheel end is more accessible, use a breaker bar and socket on fl 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 fi 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.

2762 690 13 Rev. A KohlerEngines.com

Air Cleaner/Intake

AIR CLEANER

These systems are CARB/EPA certifi ed and components
should not be altered or modifi ed in any way.

Low-Profi le Air Cleaner Components

B

C

D

E

A

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

F

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.

Low-Profi le

Loosen knobs and remove air cleaner cover.

Precleaner

1. Remove precleaner from paper element.

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

3. Saturate precleaner with new engine oil; squeeze
out excess oil.

4. Reinstall precleaner over paper element.

Paper Element

1. Rotate element latch (if equipped); remove paper
element with precleaner.

2. Separate precleaner from element; service
precleaner and replace paper element.

3. Install new paper element on base; install precleaner
over paper element; rotate element latch (if
equipped).

Reinstall air cleaner cover and secure with knobs.

Heavy-Duty Air Cleaner Components

M

H

G Air Cleaner Housing H End Cap

I Element J Inner Element
K Ejector Area L Inlet Screen
M Retaining Clip N Filter Minder

I

K

J

L

G

N

Heavy-Duty

1. Unhook retaining clips and remove end cap(s).

2. Check and clean inlet screen (if equipped).

3. Pull air cleaner element out of housing and replace.
Check condition of inner element; replace when
dirty.

4. Check all parts for wear, cracks, or damage, and that
ejector area is clean.

5. Install new element(s).

6. Reinstall end cap(s) with dust ejector valve/screen
down; secure with retaining clips.

BREATHER TUBE

Ensure both ends of breather tube are properly
connected.

AIR COOLING

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 fi ns, and other external surfaces
of engine. Avoid spraying water at wiring harness or any
electrical components. Refer to Maintenance Schedule.

62 690 13 Rev. AKohlerEngines.com28

EFI SYSTEM

WARNING

Explosive Fuel can cause fi res and severe
burns.

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

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

Typical electronic fuel injection (EFI) system and related
components include:

● Fuel pump module and lift pump.

● Fuel fi lter.

● High pressure fuel line.

● Fuel line(s).

● Fuel injectors.

● Throttle body/intake manifold.

● Electronic control unit (ECU).

● Ignition coils.

● Engine (oil) temperature sensor.

● Throttle position sensor (TPS).

● Crankshaft position sensor.

● Oxygen sensor.

● Temperature/Manifold Absolute Pressure (TMAP)
sensor.

● Malfunction indicator light (MIL) - optional.

● 30 Amp fuse (charging system).

● 10 Amp fuse (ignition switch).

● 10 Amp fuse (battery power).

● Wire harness assembly & affi liated wiring.

FUEL RECOMMENDATIONS

Refer to Maintenance.

FUEL LINE

Low permeation fuel line must be installed on all Kohler
Co. engines to maintain EPA and CARB regulatory
compliance.

OPERATION

NOTE: When performing voltage or continuity tests,

avoid putting excessive pressure on or against
connector pins. Pin probes are recommended
for testing to avoid spreading or bending
terminals.

EFI system is designed to provide peak engine
performance with optimum fuel effi ciency and lowest
possible emissions. Ignition and injection functions
are electronically controlled, monitored and continually
corrected during operation to maintain ideal air/fuel ratio.

Central component of system is Engine Control Unit
(ECU) which manages system operation, determining
best combination of fuel mixture and ignition timing for
current operating conditions.

A lift fuel pump is used to move fuel from tank through
an in-line fuel fi lter and fuel line. Fuel is then pumped
to fuel pump module. Fuel pump module regulates
fuel pressure to a system operating pressure of 39 psi.
Fuel is delivered from fuel pump module through high
pressure fuel line into injectors, which inject fuel into
intake ports. ECU controls amount of fuel by varying
length of time that injectors are on. This can range
from 2 to over 12 milliseconds depending on fuel
requirements. Controlled injection of fuel occurs every
other crankshaft revolution, or once for each 4-stroke
cycle. When intake valve opens, air/fuel mixture is drawn
into combustion chamber,compressed, ignited, and
burned.

ECU controls amount of fuel being injected and ignition
timing by monitoring primary sensor signals for engine
temperature, speed (RPM), and throttle position (load).
These primary signals are compared to preprogrammed
maps in ECU computer chip, and ECU adjusts fuel
delivery to match mapped values. After engine reaches
operating temperature, an exhaust gas oxygen sensor
provides feedback to ECU based upon amount of
unused oxygen in exhaust, indicating whether fuel
mixture being delivered is rich or lean. Based upon this
feedback, ECU further adjusts fuel input to re-establish
ideal air/fuel ratio. This operating mode is referred to as
closed loop operation. EFI system operates closed loop
when all three of following conditions are met:

● Oil temperature is greater than 50-60°C (122-140°F).

● Oxygen sensor has warmed suffi ciently to provide a
signal (minimum 400°C, 752°F).

● Engine operation is at a steady state (not starting,
warming up, accelerating, etc.).

During closed loop operation ECU has ability to readjust
and learn adaptive controls, providing compensation
for changes in overall engine condition and operating
environment, so it will be able to maintain ideal air/
fuel ratio. This system requires a minimum engine
oil temperature greater than 60-70°C (140-158°F) to
properly adapt. These adaptive values are maintained as
long as ECU is not reset.

During certain operating periods such as cold starts,
warm up, acceleration, high load, etc., a richer air/fuel
ratio is required and system operates in an open loop
mode. In open loop operation oxygen sensor output is
used to ensure engine is running rich, and controlling
adjustments are based on primary sensor signals and
programmed maps only. This system operates open
loop whenever three conditions for closed loop operation
(above) are not being met.

ECU is brain or central processing computer of entire
EFI system. During operation, sensors continuously
gather data which is relayed through wiring harness
to input circuits within ECU. Signals to ECU include:
ignition (on/off ), crankshaft position and speed (RPM),
throttle position, oil temperature, intake air temperature,
exhaust oxygen levels, manifold absolute pressure, and
battery voltage.

62 690 13 Rev. A KohlerEngines.com

29

EFI SYSTEM

ECU compares input signals to programmed maps in
its memory to determine appropriate fuel and spark
requirements for immediate operating conditions. ECU
then sends output signals to set injector duration and
ignition timing.

ECU continually performs a diagnostic check of itself,
each of sensors, and system performance. If a fault
is detected, ECU can turn on a Malfunction Indicator
Light (MIL) (if equipped) on equipment control panel,
store fault code in its fault memory, and go into a default
operating mode. Depending on signifi cance or severity
of fault, normal operation may continue. A technician can
access stored fault code using a blink code diagnosis
fl ashed out through MIL. An optional computer software
diagnostic program is also available, see Tools and Aids.

ECU requires a minimum of 6.0 volts to operate.
To prevent engine over-speed and possible failure, a

rev-limiting feature is programmed into ECU. If maximum
RPM limit (4500) is exceeded, ECU suppresses injection
signals, cutting off fuel fl ow. This process repeats itself in
rapid succession, limiting operation to preset maximum.

Wiring harness used in EFI system connects electrical
components, providing current and ground paths for
system to operate. All input and output signaling occurs
through two special all weather connectors that attach
and lock to ECU. Connectors are Black and Grey and
keyed diff erently to prevent being attached to ECU
incorrectly.

Condition of wiring, connectors, and terminal
connections is essential to system function and
performance. Corrosion, moisture, and poor connections
are as likely cause of operating problems and system
errors as an actual component. Refer to Electrical
System for additional information.

EFI system is a 12 VDC negative ground system,
designed to operate down to a minimum of 6.0 volts.
If system voltage drops below this level, operation
of voltage sensitive components such as ECU, fuel
pump, ignition coils, and injectors will be intermittent
or disrupted, causing erratic operation or hard starting.
A fully charged, 12 volt battery with a minimum of 350
cold cranking amps is important in maintaining steady
and reliable system operation. Battery condition and
state of charge should always be checked fi rst when
troubleshooting an operational problem.

Keep in mind that EFI-related problems are often caused
by wiring harness or connections. Even small amounts
of corrosion or oxidation on terminals can interfere with
milliamp currents used in system operation.

Cleaning connectors and grounds will solve problems
in many cases. In an emergency situation, simply
disconnecting and reconnecting connectors may clean
up contacts enough to restore operation, at least
temporarily.

If a fault code indicates a problem with an electrical
component, disconnect ECU connector and test for
continuity between component connector terminals and
corresponding terminals in ECU connector using an
ohmmeter. Little or no resistance should be measured,
indicating that wiring of that particular circuit is OK.

Crankshaft position sensor is essential to engine
operation; constantly monitoring rotation and speed
(RPM) of crankshaft. There are 23 consecutive teeth
cast into fl ywheel. One tooth is missing and is used to
reference crankshaft position for ECU.

During rotation, an AC voltage pulse is created within
sensor for each passing tooth. ECU calculates engine
speed from time interval between consecutive pulses.
Gap from missing tooth creates an interrupted input
signal, corresponding to specifi c crankshaft position near
BDC for cylinder #1. This signal serves as a reference
for control of ignition timing by ECU. Synchronization of
inductive speed pickup and crankshaft position takes
place during fi rst two revolutions each time engine is
started. Sensor must be properly connected at all times.
If sensor becomes disconnected for any reason, engine
will quit running.

Throttle position sensor (TPS) is used to indicate throttle
plate angle to ECU. Since throttle (by way of governor)
reacts to engine load, angle of throttle plate is directly
related to load on engine.

Mounted on throttle body and operated directly off end
of throttle shaft, TPS works as a potentiometer, varying
voltage signal to ECU in direct correlation to angle
of throttle plate. This signal, along with other sensor
signals, is processed by ECU and compared to internal
preprogrammed maps to determine required fuel and
ignition settings for amount of load.

Correct position of TPS is established and set at factory.
Do not loosen TPS or alter mounting position unless
absolutely required by fault code diagnosis. If TPS
is loosened or repositioned, appropriate TPS Learn
Procedure must be performed to re-establish baseline
relationship between ECU and TPS.

Engine (oil) temperature sensor is used by system to
help determine fuel requirements for starting (a cold
engine needs more fuel than one at or near operating
temperature).

Mounted in crankcase next to breather cover, it has
a temperature-sensitive resistor that extends into oil
fl ow. Resistance changes with oil temperature, altering
voltage sent to ECU. Using a table stored in its memory,
ECU correlates voltage drop to a specifi c temperature.
Using fuel delivery maps, ECU then knows how much
fuel is required for starting at that temperature.

Temperature/Manifold Absolute Pressure (TMAP) sensor
is an integrated sensor that checks both intake air
temperature and manifold absolute pressure.

Intake Air Temperature control is a thermally sensitive
resistor that exhibits a change in electrical resistance
with a change in its temperature. When sensor is cold,
resistance of sensor is high. As sensor warms up,
resistance drops and voltage signal increases. From
voltage signal, ECU can determine temperature of intake
air.

Purpose of sensing air temperature is to help ECU
calculate air density. Higher air temperature less dense
air becomes. As air becomes less dense ECU knows
that it needs to lessen fuel fl ow to achieve correct air/fuel
ratio. If fuel ratio was not changed engine would become
rich, possibly losing power and consuming more fuel.

30

62 690 13 Rev. AKohlerEngines.com