Kohler Command PRO EFI User manual

ECH630-ECH749, CH735, CH26, CH745
Service Manual
KohlerEngines.com 124 690 01 Rev. S
2 Safety
3 Maintenance
5 Specifications
23 Tools and Aids
26 Troubleshooting
31 Air Cleaner/Intake
32 Electronic Fuel Injection (EFI) System-Electronic Throttle Body (ETB) ECH
65 Electronic Fuel Injection (EFI) System-ECH WITH OXYGEN SENSOR
94 Electronic Fuel Injection (EFI) System-ECH WITHOUT OXYGEN SENSOR
115 Electronic Fuel Injection (EFI) System-Bosch
148 Lubrication System
150 Electrical System
157 Starter System
161 Disassembly/Inspection and Service
182 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
2 24 690 01 Rev. SKohlerEngines.com
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
fires and severe burns.
Do not fill fuel tank while
engine is hot or running.
Gasoline is extremely flammable
and its vapors can explode if
ignited. Store gasoline only in
approved containers, in well
ventilated, unoccupied buildings,
away from sparks or flames.
Spilled fuel could ignite if it comes
in contact with hot parts or sparks
from ignition. Never use gasoline
as a cleaning agent.
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. Never run engine
indoors or in enclosed
spaces.
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 flammable. 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 flywheel.
WARNING
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.
WARNING
Explosive Fuel can
cause fires 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.

Maintenance
324 690 01 Rev. S 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
Every 25 Hours or Annually¹
●Service/replace low-profile precleaner (if equipped). Air Cleaner/Intake
Every 100 Hours or Annually¹
●Change oil. Lubrication System
●Replace low-profile air cleaner element. Air Cleaner/Intake
●Remove and clean shrouds and cooling areas. Inspect for any debris visible
through flywheel cooling holes (if equipped) and clean as necessary. Air Cleaner/Intake
●Check oil cooler fins, clean as necessary (if equipped). Lubrication System
Every 150 Hours
●Check heavy-duty filter minder. Air Cleaner/Intake
●Inspect heavy-duty air filter paper element and inlet screen area. Air Cleaner/Intake
Every 200 Hours¹
●Replace unique Electronic Fuel Injection (EFI) fuel filter.
Every 200 Hours
●Change oil filter. Lubrication System
Every 300 Hours¹
●Replace heavy-duty air cleaner element and check inner element. Air Cleaner/Intake
Every 300 Hours²
●Change oil and filter (KOHLER PRO 10W-50 oil and KOHLER PRO filter only). Lubrication System
Every 500 Hours or Annually¹
●Replace spark plugs and set gap. Electrical System
Every 600 Hours¹
●Replace heavy-duty air cleaner inner element. Air Cleaner/Intake
¹Perform these procedures more frequently under severe, dusty, dirty conditions.
²Option only if using KOHLER®PRO oil and PRO filter.
REPAIRS/SERVICE PARTS
Kohler genuine service parts can be purchased from Kohler authorized dealers. To find a local Kohler authorized
dealer visit KohlerEngines.com or call 1-800-544-2444 (U.S. and Canada).

Maintenance
4 24 690 01 Rev. SKohlerEngines.com
OIL RECOMMENDATIONS
All-season KOHLER®PRO 10W-50 Synthetic Oil is the
ideal oil for KOHLER engines. It is specifically formulated
to extend the oil and oil filter change interval to 300
Hours when paired with a KOHLER PRO Extended Life
Oil Filter.
300-Hour oil and oil filter change intervals are exclusive
to and only authorized on KOHLER engines that utilize
both the KOHLER PRO 10W-50 Synthetic Oil and
KOHLER PRO Extended Life Oil Filter. Alternative
engine oils and oil filters may be used with KOHLER
engines but require 100-Hour oil and 200-Hour oil filter
change intervals for proper maintenance. Oil must be
API (American Petroleum Institute) service class SJ or
higher. Select viscosity based on air temperature at time
of operation as shown below.
°F -20 020324060
50 80 100
°C -30 -20 -10 0 10 20 30 40
5W-30
10W-30
SAE 30
Kohler PRO 10W-50
FUEL RECOMMENDATIONS
WARNING
Explosive Fuel can cause fires and severe
burns.
Do not fill fuel tank while engine is hot or
running.
Gasoline is extremely flammable and its vapors can
explode if ignited. Store gasoline only in approved
containers, in well ventilated, unoccupied buildings,
away from sparks or flames. Spilled fuel could ignite
if it comes in contact with hot parts or sparks from
ignition. Never use gasoline as a cleaning agent.
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 overfill 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
(Not required if using KOHLER PRO 10W-50
full-synthetic oil). 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.

Specifications
524 690 01 Rev. S KohlerEngines.com
Engine Dimensions with Heavy-Duty Air Cleaner-Flywheel Side
AValve Cover B451.16 mm (17.762 in.) CFuel Pump D342.52 mm
(13.485 in.)
E230.20 mm (9.063 in.) F130.0 mm (5.118 in.) G88.28 mm
(3.475 in.) H298.93 mm (11.769 in.)
I277.22 mm (10.914 in.) J135.0 mm (5.315 in.) K
77.17 mm
(3.038 in.) Spark Plug
Removal
L
67.19 mm
(2.645 in.) Spark
Plug Boot Removal
M
37.15 mm
(1.463 in.) Spark Plug
Boot
N
320.89 mm
(12.633 in.) Spark Plug
Removal
O
315.14 mm
(12.407 in.) Spark
Plug Boot Removal
P20°
QEngine Mounting
Surface R4X Ø 10.3 mm (0.406 in.) S184.20 mm (7.252 in.) TEngine Center Line
U92.10 mm (3.626 in.) VCenter Line Mounting
Hole "A" W134.80 mm (5.307 in.) X
15.70 mm
(0.618 in.) Oil Filter
Removal
YCrankshaft Center Line Z
315.25 mm
(12.412 in.) Spark Plug
Boot Removal
AA 4.12 mm (0.182 in.)
Spark Plug Boot AB
25.46 mm
(1.002 in.) Spark
Plug Boot Removal
AC Fuel Filter AD 39.66 mm (1.562 in.)
Spark Plug Removal AE Fuel Pump
F
E
G
H
I
K
L
N
O
M
P
Q
R
S
T
A
B
D
C
J
U
V
X
W
N
Y
Z
AD
AA
AB
AC
P
AE

Specifications
6 24 690 01 Rev. SKohlerEngines.com
A
B
C
D
E
F
G
H
I
J
K
L
MN
O
PR
Q
S
V
T
U
WX
Y
A371.44 mm
(14.624 in.) B209.88 mm (8.263 in.) C52.43 mm (2.064 in.) D
30.0 mm (1.181 in.)
Spark Plug Center
Line
E32.00 mm (1.260 in.)
Exhaust Port #2 FOil Fill GDipstick H101.38 mm (3.992 in.)
I85.50 mm (3.366 in.)
Keyway J1/4 in. Square Keyway K622.70 mm (24.516 in.) L
7/16-20 UNF-2B in.
38.10 mm (1.5 in.)
Deep
M155.58 mm (6.125 in.) N152.08 mm (5.987 in.)
Oil Filter OEngine Mounting Surface P4.00 mm (0.157 in.) Pilot
Q52.75 mm (2.077 in.)
Oil Filter RCenter Line Mounting Hole "A" S100.0 mm (3.937 in.) T89.0 mm (3.504 in.)
U51.0 mm (2.008 in.) VOil Drain Plug
3/8 in. NPT W12.28 mm (0.483 in.) XRectifier-Regulator
YFuel Pump
Engine Dimensions with Heavy-Duty Air Cleaner-Oil Filter Side

Specifications
724 690 01 Rev. S KohlerEngines.com
Engine Dimensions with Heavy-Duty Air Cleaner-PTO Side
B
A
C
E
F
D
G
H
I
J
L
K
M
N
PO
Q
S
R
U
T
V
G
A335.04 mm (13.19 in.) B122.10 mm (4.807 in.) C65.0 mm (2.559 in.)
Muffler Mounting D75.42 mm (2.969 in.)
ELift Strap FOil Fill Location G30° H50.00 mm (1.969 in.)
Exhaust Port #2
I2 X 306.24 mm
(12.136 in.) J
2 X M8 X 1.25
20.5 mm
(0.807 in.) Deep
K135° L
5/16-24 UNC-2B in.
17 mm (0.669 in.)
Deep
127 mm (5.0 in.)
B.C.
M
3/8-16 UNC-2B in.
21 mm (0.827 in.)
Deep
165.1 mm (6.5 in.)
B.C.
N
7/16-14 UNC-2B in.
21 mm (0.827 in.)
Deep 196.8 mm
(7.75 in.) B.C.
OCenter Line Mounting
Hole "A" P177.8 mm (7.0 in.) Pilot Diameter
QEngine Mounting
Surface RSolenoid Shift Starter S283.58 mm (11.164 in.) Muffler Mounting T50.00 mm (1.969 in.) Exhaust Port #1
UM8 X 1.25 4 Studs V45°
GG

Specifications
8 24 690 01 Rev. SKohlerEngines.com
Engine Dimensions with Heavy-Duty Air Cleaner-Starter Side
A
B
C
D
E
GF
H
I
J
K
L
A
50.0 mm (1.969 in.)
Center Line Spark
Plug
B12.0 mm (0.472 in.)
Exhaust Port #1 C
67.50 mm (2.657 in.)
Muffler Mounting
Bosses
DDipstick
E432.58 mm
(17.031 in.) FEngine Mounting Surface GCenter Line Mounting Hole "A" H89.0 mm (3.504 in.)
I51.0 mm (2.008 in.) JOil Drain Plug 3/8 in. K12.28 mm (0.483 in.) LLift Strap

Specifications
924 690 01 Rev. S KohlerEngines.com
Engine Dimensions with Low-Profile Air Cleaner-Flywheel Side
F
E
G
H
I
K
L
N
O
M
P
Q
R
S
T
A
B
D
C
J
U
V
X
WY
ZAA
J
I
A451.16 mm (17.762 in.) B298.93 mm (11.769 in.) CValve Cover D12.95 mm (0.510 in.)
E
67.19 mm
(2.645 in.) Spark
Plug Boot Removal
F
77.17 mm
(3.038 in.) Spark
Plug Removal
G
37.15 mm
(1.463 in.) Spark
Plug Boot
H473.43 mm
(18.639 in.)
I
320.89 mm
(3.038 in.) Spark
Plug Removal
J20° K
315.14 mm
(12.407 in.) Spark
Plug Boot Removal
LEngine Mounting
Surface
M4X Ø 10.3 mm
(0.406 in.) N184.20 mm (7.252 in.) OEngine Center Line P92.10 mm (3.628 in.)
QCenter Line Mounting
Hole "A" R134.80 mm (5.307 in.) S
15.70 mm
(0.618 in.) Oil Filter
Removal
TCrankshaft Center
Line
U
315.25 mm
(12.412 in.) Spark Plug
Boot Removal
VFuel Filter W4.12 mm (0.162 in.)
Spark Plug Boot X
29.58 mm
(1.165 in.) Spark
Plug Boot Removal
Y
60.0 mm (2.362 in.) Air
Cleaner Cover
Removal
Z39.66 mm (1.562 in.)
Spark Plug Removal AA Fuel Pump

Specifications
10 24 690 01 Rev. SKohlerEngines.com
Engine Dimensions with Low-Profile Air Cleaner-Oil Filter Side
A
BC
D
E
F
GH
I
J K
L
M
N
O
P
R
Q
S
V
T
U
A371.44 mm
(14.624 in.) B
30.0 mm (1.181 in.)
Spark Plug Center
Line
CFuel Pump DOil Fill
EDipstick F101.38 mm (3.992 in.) G85.50 mm (3.366 in.)
Keyway H1/4 in. Square Keyway
I
7/16-20 UNF 2B in.
38.10 mm (1.5 in.)
Deep
J155.58 mm (6.125 in.) K152.08 mm (5.987 in.)
Oil Filter LEngine Mounting Surface
MMounting Surface N4.00 mm (0.157 in.)
Pilot OCenter Line Mounting Hole "A" P100.0 mm (3.937 in.)
Q52.75 mm (2.077 in.)
Oil Filter R51.0 mm (2.008 in.) S89.0 mm (3.504 in.) TOil Drain Plug 3/8 in. NPT
U12.28 mm (0.483 in.) VRectifier-Regulator