Kohler KT610 User manual

32 590 16 Rev. -- KohlerEngines.com
KT610-KT620, KT715-KT745
Owner's 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.
Warranty coverage as outlined in the warranty card and on
KohlerEngines.com. Please review carefully as it provides you
specific rights and obligations.
To maintain compliance with applicable emission regulations,
exhaust system backpressure may not exceed limits which can
be found on KohlerEngines.com. Search by Model No., select
Read More, then select Specs tab.
Record engine information to reference when ordering parts or obtaining warranty coverage.
Engine Model
Specification
Serial Number
Purchase Date
EN
ESS
FRC

2 32 590 16 Rev. --KohlerEngines.com
California Proposition 65 Warning
Engine exhaust from this product contains chemicals known
to State of California to cause cancer, birth defects, or other
reproductive harm.
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
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
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
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
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.
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.
CAUTION
Electrical Shock
can cause injury.
Do not touch
wires while
engine is
running.
California Proposition 65 Warning
This product contains chemicals known to State of California to
cause cancer, birth defects, or other reproductive harm.

3
32 590 16 Rev. -- KohlerEngines.com
EN
AAir Cleaner
Cover BDebris Screen CFuel Filter DOil Filter
EOil Fill/Dipstick FOil Drain Plug GSpark Plug HAir Cleaner
Cover Lever
Visit KohlerEngines.com for service parts information and purchasing options.
Pre-Start Checklist
1. Check oil level. Add oil if low. Do not overfill.
2. Check fuel level. Add fuel if low. Check fuel system components and lines for leaks.
3. Check and clean cooling areas, air intake areas and external surfaces of engine (particularly
after storage).
4. Check that air cleaner components and all shrouds, equipment covers, and guards are in place
and securely fastened.
5. Check spark arrestor (if equipped).
E
H
C
D
A
B
B
E
F
G
G
H
A

4 32 590 16 Rev. --KohlerEngines.com
Starting
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
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.
Standard Choke System
●Above 32°F (0°C)
Refer to operating instructions of equipment
this engine powers for specific starting
instructions.
●32°F (0°C) and Below
1. Refer to operating instructions of equipment
this engine powers for specific starting
instructions.
2. Refer to Cold Weather Starting Hints within
this manual.
Smart-ChokeTM
●Above 32°F (0°C)
1. This feature will automatically adjust engine
choke on start up with throttle in any position.
2. If engine does not start on first attempt, wait
3-5 seconds and try again (if no start after
third attempt wait 1 minute).
3. If engine does not consistently start by fifth
attempt, consult Kohler authorized dealer for
assistance.
●32°F (0°C) and Below
1. This feature will automatically adjust engine
choke on start up with throttle in any position
(winter blend fuel is recommended).
2. If engine does not start on first attempt, wait
5-10 seconds and try again (if no start after
third attempt wait 1 minute).
3. If engine does not consistently start by fifth
attempt, consult Kohler authorized dealer for
assistance.
eChokeTM
●Above 32°F (0°C)
1. This feature will automatically make system
adjustments to engine on start up with
throttle in any position.
2. If engine does not start on first attempt, wait
3-5 seconds and try again (if no start after
third attempt wait 1 minute).
3. If engine does not start consistently by fifth
attempt, turn key to OFF, pause briefly, and
make another attempt. If engine does not
start, consult Kohler authorized dealer for
assistance.
●32°F (0°C) and Below
1. This feature will automatically make system
adjustments to engine on start up with
throttle in any position (winter blend fuel is
recommended).
2. If engine does not start on first attempt, wait
3-5 seconds and try again (if no start after
third attempt wait 1 minute).
3. If engine does not start consistently by fifth
attempt, turn key to OFF, pause briefly, and
make another attempt. If engine does not
start, consult Kohler authorized dealer for
assistance.
Cold Weather Starting Hints
1. Use proper oil for temperature expected.
2. Disengage all possible external loads.
3. Use fresh winter grade fuel. Winter grade
fuel has higher volatility to improve starting.
4. Make sure battery has a full charge.
Stopping
1. If possible, remove load by disengaging all
PTO driven attachments.
2. Position throttle control between half and full
throttle; stop engine.
3. Do not allow engine/application to be left
unattended with key ON (RUN position) for
long periods. If left in such a condition,
operator must turn key completely OFF
before attempting a restart to reset system.
Angle of Operation
Refer to operating instructions of equipment
this engine powers. Do not operate this engine
exceeding maximum angle of operation; see
specification table. Engine damage could result
from insufficient lubrication.
Engine Speed
NOTE: Do not tamper with governor setting to
increase maximum engine speed.
Overspeed is hazardous and will void
warranty.

5
32 590 16 Rev. -- KohlerEngines.com
EN
High Altitude Operation
If this engine is operated at an altitude of 4000 ft. (1219 meters) or above, a high altitude carburetor
kit is required. To obtain high altitude carburetor kit information or to find 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 configuration below 4000 ft. (1219 meters).
Operating this engine with the wrong engine configuration at a given altitude may increase its
emissions, decrease fuel efficiency and performance, and result in damage to the engine.
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 found at KohlerEngines.com or 1-800-544-2444 (U.S. and Canada).
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.
°F -20 020324060
50 80 100
°C -30 -20 -10 0 10 20 30 40
5W-30
10W-30
SAE 30
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 fill/dipstick
areas of any debris.
1. Remove dipstick; wipe oil off.
2. Reinsert dipstick into tube; press completely
down.
3. Remove dipstick; check oil level. Level
should be at top of indicator on dipstick.
4. If oil is low on indicator, add oil up to top of
indicator mark.
5. Reinstall and secure dipstick.
Maintenance Schedule
Every 25 Hours¹
●Service/replace precleaner.
●Replace air cleaner element (if not equipped with precleaner).
Every 100 Hours¹
●Replace air cleaner element (if equipped with precleaner).
●Change oil and filter.
●Remove cooling shrouds and clean cooling areas.
Every 100 Hours
●Check that all fasteners are in place and components are properly secured.
●Replace fuel filter.
Every 500 Hours²
●Have valve lash checked/adjusted.
Every 500 Hours
●Replace spark plugs and set gap.
¹ Perform these procedures more frequently under severe, dusty, dirty conditions.
² Have a Kohler authorized dealer perform this service.

6 32 590 16 Rev. --KohlerEngines.com
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.
Fuel Line
Low permeation fuel line must be installed on
carbureted Kohler Co. engines to maintain EPA
and CARB regulatory compliance.
Change Oil and Filter
Change oil while engine is warm.
1. Clean area around oil fill cap/dipstick.
Remove drain plug and oil fill cap/dipstick.
Allow oil to drain completely.
2. Clean area around oil filter. Place a container
under filter to catch any oil and remove filter.
Wipe off mounting surface. Reinstall drain
plug. Torque to 10 ft. lb. (13.6 N·m).
3. Place new filter in shallow pan with open end
up. Fill with new oil until oil reaches bottom
of threads. Allow 2 minutes for oil to be
absorbed by filter material.
4. Apply a thin film of clean oil to rubber gasket
on new filter.
5. Refer to instructions on oil filter for proper
installation.
6. Fill crankcase with new oil. Level should be
at top of indicator on dipstick.
7. Reinstall oil fill cap/dipstick and tighten
securely.
8. Start engine; check for oil leaks. Stop engine;
correct leaks. Recheck oil level.
9. Dispose of used oil and filter in accordance
with local ordinances.
Oil Sentry™(if equipped)
This switch is designed to prevent engine
from starting in a low oil or no oil condition. Oil
Sentry™may not shut down a running engine
before damage occurs. In some applications
this switch may activate a warning signal. Read
your equipment manuals for more information.

7
32 590 16 Rev. -- KohlerEngines.com
EN
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 fins, and other
external surfaces of engine. Avoid spraying
water at wiring harness or any electrical
components. See Maintenance Schedule.
Repairs/Service Parts
We recommend that you use a Kohler
authorized dealer for all maintenance, service,
and engine parts. To find a Kohler authorized
dealer visit KohlerEngines.com or call 1-800-
544-2444 (U.S. and Canada).
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
(failure 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.
Spark Plugs
CAUTION
Electrical Shock can cause injury.
Do not touch wires while engine
is running.
Clean out spark plug recess. Remove plug and
replace.
1. Check gap using wire feeler gauge. Adjust
gap, see specification table for adjustment.
2. Install plug into cylinder head.
3. Torque plug to 20 ft. lb. (27 N·m).
Air Cleaner
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.
Rotate air cleaner cover levers outward to
unlock cover; remove air cleaner cover.
Precleaner (if equipped):
1. Remove precleaner from paper element.
2. Replace or wash precleaner in warm water
with detergent. Rinse and allow to air dry.
3. Lightly oil precleaner with new engine oil;
squeeze out excess oil.
4. Reinstall precleaner over paper element.
Paper Element:
1. Remove element from base; service
precleaner. Discard element.
2. Install precleaner over new paper element
and install on base.
Position air cleaner cover with levers outward
over air cleaner; turn levers inward to lock.

8 32 590 16 Rev. --KohlerEngines.com
Troubleshooting
Do not attempt to service or replace major engine components, or any items that require special
timing or adjustment procedures. This work should be performed by a Kohler authorized dealer.
Possible Cause
Problem No
Fuel Improper Fuel
Dirt In
Fuel
Line
Dirty
Debris
Screen Incorrect Oil Level Engine Overloaded Dirty Air Cleaner
Faulty
Spark
Plug
Will Not Start ●●● ● ● ● ●
Hard Starting ●● ●●●●
Stops Suddenly ● ●●●●●●
Lacks Power ●●●● ● ● ●
Operates Erratically ●●● ● ● ●
Knocks or Pings ●● ● ●
Skips or Misfires ●●● ● ●
Backfires ●● ● ● ●
Overheats ●●●● ● ●
High Fuel
Consumption ●●●
Engine Specifications
Model Bore Stroke Displacement Oil Capacity
(Refill) Spark Plug Gap
Maximum Angle
of Operation
(@ full oil level)*
KT610
3.27 in.
(83 mm)
2.4 in.
(61 mm) 40.3 cu. in. (660 cc)
2.0 U.S. qt.
(1.9 L) 0.03 in. (0.76 mm) 25°
KT620
KT715
2.6 in.
(67 mm) 44.2 cu. in. (725 cc)
KT725
KT730
KT735
KT740
KT745
2.7 in.
(69 mm) 45.6 cu. in. (747 cc)
*Exceeding maximum angle of operation may cause engine damage from insufficient lubrication.
Additional specification information can be found in service manual at KohlerEngines.com.
Exhaust Emission Control System for models KT610-KT620, KT715-KT745 is EM for U.S. EPA,
California, and Europe.
Any and all horsepower (hp) references by Kohler are Certified Power Ratings and per SAE J1940
& J1995 hp standards. Details on Certified Power Ratings can be found at KohlerEngines.com.