Kohler PCH680 User manual

24 590 35 Rev. B KohlerEngines.com
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 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
PCH680, PCH740
PCV680, PCV740
Propane Electronic Fuel Injection (EFI)

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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.
If a gaseous
odor is detected,
ventilate area
and contact
an authorized
service
technician.
Propane is extremely
flammable and is heavier
than air and tends to settle
in low areas where a spark
or flame could ignite gas.
Do not start or operate this
engine in a poorly ventilated
area where leaking gas
could accumulate and
endanger safety of persons
in area.
To ensure personal safety,
installation and repair
of propane fuel supply
systems must be performed
only by qualified propane
system technicians.
Improperly installed and
maintained propane
equipment could cause
fuel supply system or other
components to malfunction,
causing gas leaks.
Observe federal, state
and local laws governing
propane fuel, storage, and
systems.
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
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
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.
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.
CAUTION
Electrical Shock
can cause injury.
Do not touch
wires while
engine is
running.
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.
Before disconnecting
negative (-) ground cable,
make sure all switches
are OFF. If ON, a spark
will occur at ground cable
terminal which could cause
an explosion if hydrogen
gas or propane fuel vapors
are present.
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.

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I
KJ
L
P
M
E
F
G
N
O
D
B
A
C
H
Q
Y
S
T
Z
AB
U
W
R
AC
V
X
AD
AE
AA
AEnd Cap BElement CInner Element DRetaining Clip
EInlet Screen FAir Cleaner
Housing GEjector Area HHeavy-Duty Air Cleaner
IAir Cleaner
Knob JWing Nut KAir Cleaner Cover LElement Cover
MPrecleaner NPaper Element OAir Cleaner
Base PRubber Seal
QLow-Profile Air
Cleaner RDebris Screen SOil Filter TVaporizer/ Regulator
U
Vaporizer/
Regulator Inlet
Filter
V
Vaporizer/
Regulator Drain
Plug
WLock-Off XUnique EFI Fuel
Filter
YSpark Plug ZOil Cooler AA Oil Fill/Dipstick AB Filter Minder
AC Oil Fill AD Oil Drain Plug AE Dipstick
Visit KohlerEngines.com for service parts information and purchasing options.

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Pre-Start Checklist
1. Check oil level. Add oil if low. Do not overfill.
2. Check fuel gauge (if equipped). If propane
tank is low, have it refilled. 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).
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.
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: Upon start-up, a metallic ticking may
occur. Run engine for 5 minutes. If
noise continues, run engine at mid
throttle for 20 minutes. If noise persists,
take engine to your local Kohler
authorized dealer.
1. Place throttle control midway between slow
and fast positions.
2. Slowly turn fuel valve on propane tank to full
open position.
3. Turn key switch to START position. Release
switch as soon as engine starts. If starter
does not turn engine over, shut off key switch
immediately. Do not make further attempts to
start engine until condition is corrected. Do
not jump start. See your Kohler authorized
dealer for trouble analysis.
Cold Weather Starting Hints
1. Use proper oil for temperature expected.
2. Disengage all possible external loads.
Stopping
1. If possible, remove load by disengaging all
PTO driven attachments.
2. Turn fuel valve to full closed position and
allow engine to continue running until it runs
out of fuel. Turn key switch to OFF position.
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.

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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).
For safety and health reasons, many states require special licensing or certification for servicing
propane fuel systems. Check local and state regulations before choosing a repair establishment to
perform fuel system repairs.
Maintenance Schedule
Every 25 Hours¹
●Service/replace low-profile precleaner (if equipped).
Every 100 Hours
●Check oil cooler fins, clean as necessary (if equipped).
●Change oil.
Every 100 Hours¹
●Replace low-profile air cleaner element (if equipped).
●Remove cooling shrouds and clean cooling areas.
Every 150 Hours
●Check heavy-duty filter minder.
●Inspect heavy-duty air filter paper element and inlet screen area.
Every 200 Hours
●Change oil filter.
●Replace unique EFI fuel filters.
Every 300¹ Hours
●Replace heavy-duty air cleaner element and check inner element.
Every 300 Hours or Annually
●Replace spark plugs and set gap.
Every 500 Hours or Annually
●Check all lines (high pressure/vacuum) including fittings for leaks.
●Drain vaporizer/regulator of accumulated fuel deposits.
Every 500 Hours or Annually2
●Inspect lock-off assembly for damage/leakage.
●Have combustion deposits removed if using non-synthetic oil.
Every 600 Hours or Annually1
●Replace heavy-duty air cleaner inner element.
Every 1500 Hours2
●Have vaporizer/regulator tested.
1Perform these procedures more frequently under severe, dusty, dirty conditions.
2Must be performed by a Kohler authorized dealer or qualified propane personnel only.

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Oil Recommendations
Synthetic oil is recommended for use in
propane fueled engines. 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.
a. Press-in cap: reinsert dipstick into tube;
press completely down.
or
b. Thread-on 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 and Filter
Change oil while engine is warm.
1. Clean area around oil fill cap/dipstick and
drain plug. 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.

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Fuel Recommendations
WARNING
Explosive Fuel can cause fires
and severe burns.
If a gaseous odor is detected,
ventilate area and contact an
authorized service technician.
Propane is extremely flammable and is
heavier than air and tends to settle in low
areas where a spark or flame could ignite
gas. Do not start or operate this engine in
a poorly ventilated area where leaking gas
could accumulate and endanger safety of
persons in area.
To ensure personal safety, installation and
repair of propane fuel supply systems must
be performed only by qualified propane
system technicians. Improperly installed and
maintained propane equipment could cause
fuel supply system or other components to
malfunction, causing gas leaks.
Observe federal, state and local laws
governing propane fuel, storage, and
systems.
This engine is certified to operate on
commercial propane (per GPA STD 2140). If
you have any questions, contact your propane
supplier.
Propane from an appropriate propane fuel tank
(supplied separately) is required to operate this
engine.
Vaporizer/Regulator
In compliance with government emission
standards, vaporizer/regulator is preset
at factory to provide proper supply of fuel.
No adjustment or resetting of vaporizer/
regulator is to be made. All service relating to
vaporizer/regulator must be performed by a
Kohler authorized dealer or qualified propane
personnel only.
Vaporizer/regulator can change propane from
supply tank to a gaseous/vapor state.
Lock-Off assembly opens and closes controlling
fuel flow from supply tank before reaching
vaporizer/regulator.
Over time, fuel deposits can accumulate inside
vaporizer/regulator. Removing these deposits
is recommended. Follow steps below to drain
vaporizer/regulators.
1. Turn fuel supply valve off, run engine out of
fuel, and turn off ignition switch.
2. Disconnect and ground spark plug leads.
3. Remove drain plug from bottom of vaporizer/
regulator. Remove any accumulated
deposits.
4. Reinstall plug and tighten securely. If
required, a replacement plug can be found at
KohlerEngines.com.
Fuel Line
High pressure fuel line meeting a minimum of
SAE R7 standard must be installed on Kohler
Co. engines equipped with propane EFI system
(from vaporizer/regulator to injectors).
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).
Electronic Fuel Injection (EFI) System
EFI is an electronically-controlled fuel
management system which is monitored by an
Electronic Control Unit (ECU). A Malfunction
Indicator Light (MIL) will illuminate if problems
or faults are detected. Servicing by a Kohler
authorized dealer is necessary.
Fuel System Components
Engines are equipped with special EFI fuel
filters. See Maintenance Schedule.
Fuse Replacement
This engine has three (3) blade type automotive
fuses. Replacement fuses must have same
rating as blown fuse. Use fuse chart below to
determine correct fuse.
Wire Color Fuse Rating
2 Solid Red Wires 10-amp Fuse
1 Red Wire with Black Stripe
1 Red Wire with White Stripe 10-amp Fuse
2 Purple Wires 30-amp Fuse

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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.
Low-Profile
Loosen knob 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. Clean area around element. Remove wing
nut, element cover, and paper element with
precleaner.
2. Separate precleaner from element; service
precleaner and replace paper element.
3. Check condition of rubber seal and replace if
necessary.
4. Install new paper element on base; install
precleaner over paper element; reinstall
element cover and secure with wing nut.
Reinstall air cleaner cover and secure with
knob.
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 (if equipped)
Ensure end of breather tube is properly
connected.
Oil Cooler (if equipped)
1. Clean fins with a brush or compressed air.
2. Remove two screws securing oil cooler, and
tilt to clean back side.
3. Reinstall oil cooler.
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).
Leakage Check/Testing
With fuel valve fully opened, engine not
running, turn key switch ON. Check all fuel
system connections and lines for leaks using
soapy water. Any leakage must be corrected
before restarting engine. Have service
performed by a Kohler authorized dealer or
qualified propane personnel only.
Storage
If engine will be out of service for 2 months or
more follow procedure below.
1. 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.
2. Disconnect negative (-) battery cable.
3. Separate propane tank from unit and store
separately in an area designated for safe
propane tank storage.
4. Store engine in a clean, dry place.

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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
Tank
Nearly
Empty
Improper
Fuel
Dirt In
Fuel Line
Broken
Fusible Link
Dirty/
Restricted
Vaporizer/
Regulator
Inlet Filter
Dirty
Debris
Screen
Incorrect
Oil Level
Engine
Overloaded
Dirty Air
Cleaner
Faulty
Spark
Plug
Dirty/
Restricted
Vaporizer/
Regulator
Will Not Start ●●●●●●●●●● Hard Starting ●●● ●●●●●●● Stops Suddenly ●●●●●●●● Lacks Power ●●● ● ● ● ● ●● ● Operates Erratically ●● ● ● ● ●● ● Knocks or Pings ●●●●●● Skips or Misfires ●● ● ● ●● ● Backfires ●● ●●● Overheats ●● ● ● ● ● ● ● High Fuel Consumption ●●

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Engine Specifications
Model Bore Stroke Displacement Oil Capacity
(Refill) Spark Plug
Gap
Maximum Angle
of Operation
(@ full oil level)*
PCH680
3.27 in.
(83 mm)
2.72 in.
(69 mm)
45.6 cu. in.
(747 cc)
1.7-2.0 U.S. qt.
(1.6-1.9 L) 0.03 in.
(0.76 mm) 25°
PCV680
PCH740
PCV740
*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 propane EFI models PCH680, PCH740, and PCV680,
PCV740 is EM, O2S, ECM, MPI 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.

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