Kohler CH640, CH730, CH740 Owner's Manual

Download

OWNER'S MANUAL

CH640, CH730, CH740

HORIZONTAL CRANKSHAFT

Liqueﬁ ed Petroleum Gas (LPG) or LPG/Natural Gas (NG) Fueled

Safety Precautions

To ensure safe operations please read the following statements and understand their meaning. Also refer to your equipment owner's manual for other important safety information. This manual contains safety precautions which are explained below. Please read carefully.

WARNING

Warning is used to indicate the presence of a hazard that can cause severe personal injury, death, or substantial property damage if the warning is ignored.

CAUTION

Caution is used to indicate the presence of a hazard that will or can cause minor personal injury or property damage if the caution is ignored.

NOTE

Note is used to notify people of installation, operation, or maintenance information that is important but not hazard-related.

For Your Safety!

These precautions should be followed at all times. Failure to follow these precautions could result in injury to yourself and others.

WARNING

Accidental Starts can cause severe injury or death.

Disconnect and ground spark plug leads before servicing.

Accidental Starts!

Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or

equipment, disable the engine as follows:

1) Disconnect the spark plug lead(s).

2) Disconnect negative (-) ba ery cable from ba ery.

Before disconnecting the negative (-) ground cable, make sure all switches are OFF. If ON, a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or LPG/NG fuel vapors are present.

WARNING

Rotating Parts can cause severe injury.

Stay away while engine is in operation.

Rotating Parts!

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

CAUTION

Electrical Shock can cause injury.

Do not touch wires while engine is running.

WARNING

Hot Parts can cause severe burns.

Do not touch engine while operating or just a er stopping.

Hot Parts!

Engine components can get extremely hot from operation. To prevent severe burns, do not touch these areas while the engine is running, or immediately a er it is turned oﬀ . Never operate the engine with heat shields or guards removed.

California

Proposition 65 Warning

Engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm.

Electrical Shock!

Never touch electrical wires or components while the engine is running. They can be sources of electrical shock.

Safety Precautions (Cont.)

WARNING

Explosive Fuel can cause ﬁ res and severe burns.

If a gaseous odor is detected, ventilate the area and contact an authorized service technician.

Explosive Fuel!

LPG is extremely ﬂ ammable and is heavier than air and tends to se le in low areas where a spark or ﬂ ame could ignite the gas. Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger the safety of persons in the area.

NG is extremely ﬂ ammable, is lighter than air, and rises. Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger the safety of persons in the area.

To ensure personal safety, installation and repair of LPG/NG fuel supply systems must be performed only by qualiﬁ ed LPG/NG system technicians. Improperly installed and maintained LPG/NG equipment could cause fuel supply system or other components to malfunction, causing gas leaks.

WARNING

Carbon Monoxide can cause severe nausea, fainting or death.

Do not operate engine in closed or conﬁ ned area.

Lethal Exhaust Gases!

Engine exhaust gases contain poisonous carbon monoxide. Carbon monoxide is odorless, colorless, and can cause death if inhaled. Avoid inhaling exhaust fumes, and never run the engine in a closed building or conﬁ ned area.

WARNING

Explosive Gas can cause ﬁ res and severe acid burns.

Charge ba ery only in a well ventilated area. Keep sources of ignition away.

Explosive Gas!

Ba eries produce explosive hydrogen gas while being charged. To prevent a ﬁ re or explosion, charge ba eries only in well ventilated areas. Keep sparks, open ﬂ ames, and other sources of ignition away from the ba ery at all times. Keep ba eries out of the reach of children. Remove all jewelry when servicing ba eries.

Observe federal, state and local laws governing LPG/NG fuel, storage, and systems.

Congratulations – You have selected a ﬁ ne four-cycle, twin cylinder, air-cooled engine. Kohler designs long life strength and on-the-job durability into each engine...making a Kohler engine dependable...dependability you can count on. Here are some reasons why:

• Eﬃ cient overhead valve design and full pressure lubrication provide maximum power, torque, and reliability under all operating conditions.

• Dependable, maintenance free electronic ignition ensures fast, easy starts time a er time.

• Kohler engines are easy to service. All routine service areas (like the dipstick and oil ﬁ ll, air cleaner, spark plugs, and carburetor) are easily and quickly accessible.

• Parts subject to the most wear and tear (like the cylinder liner and camsha ) are made from precision formulated cast iron. Because the cylinder liner can be rebored, these engines can last even longer.

• Every Kohler engine is backed by a worldwide network of over 10,000 distributors and dealers. Service support is just a phone call away. Call 1-800-544-2444 (U.S. & Canada) for Sales & Service assistance.

To keep your engine in top operating condition, follow the maintenance procedures in this manual.

Vaporizer

Air Cleaner

Dipstick

Oil Filter

Electric Starter

Oil Drain Plug

Figure 1. Typical Command Horizontal Shaft LPG or LPG/NG Fueled Engine.

Oil Recommendations

Using the proper type and weight of oil in the crankcase is extremely important. So is checking oil daily and changing oil regularly. Using oil that is

NOTE: Using other than service class SG, SH, SJ or

higher oil or extending oil change intervals longer than recommended can cause engine damage.

incorrect or dirty can cause premature engine wear and failure. Synthetic oil is recommended for use in LPG/ NG fueled engines because there is less oxidation or

A logo or symbol on oil containers identiﬁ es the API service class and SAE viscosity grade. See Figure 3.

thickening, and deposit accumulation on intake valves is substantially reduced. Conventional petroleumbased oil may be used, but valve service will be required every 500 hours to remove the accumulated deposits.

Oil Type

Use high quality, oil of API (American Petroleum Institute) service class SG, SH, SJ or higher. Select

the viscosity based on the air temperature at the time of operation as shown in the following table.

RECOMMENDED SAE VISCOSITY GRADES

Figure 3. Oil Container Logo.

LPG Regulator

Kohler 10W-30

10W-30

5W-20, 5W-30

-20 0

°F

-30 -20

°C

TEMPERATURE RANGE EXPECTED BEFORE NEXT OIL CHANGE

-10 0

*Synthetic oils will provide be er starting in extreme cold below -23°C (-10°F).

Figure 2. Viscosity Grades Table.

40 60

10 20 30

SAE 30

100

Refer to Maintenance Instructions beginning on page 8 for detailed oil check, oil change, and oil ﬁ lter change procedures.

Fuel Recommendations

CH640 and CH740 engines are certiﬁ ed to operate on LPG or NG.

CH730 engines are certiﬁ ed to operate on LPG.

LPG Engines

LPG from an appropriate LPG fuel tank (supplied separately) is required to operate this engine.

LPG Operation

Installation of jet in regulator ﬁ  ing is required for LPG operation.

WARNING: Pressurized LPG!

Fuel tanks are ﬁ lled under pressure and should be handled with care. To prevent tank damage which could endanger the safety of the operator or persons in the area, do not drop or drag tanks on any surface. Use a hand truck when moving, or tilt the tank on its footring in a position slightly oﬀ vertical and roll it.

Avoid personal contact with LPG fuel to prevent frostbite. See a physician if frostbite occurs.

WARNING: Explosive Fuel!

LPG is extremely ﬂ ammable, is heavier than air and tends to se le in low areas where a spark or ﬂ ame could ignite the gas. Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger the safety of persons in the area.

LPG fuel consists primarily of propane, although the fuel supplier may sometimes mix other gases with propane.

Fuel tanks must be ﬁ lled only by persons qualiﬁ ed in the handling of LPG. Tanks are ﬁ lled by weight and should not be overﬁ lled (never to more than 80 percent of total capacity). An air space must be present in the tank to allow fuel to expand.

Switching from NG to LPG

NOTE: When switching from NG to LPG fuel, the ba ery must be temporarily disconnected for safety and to reset the system.

Remove the fuel inlet hose. Inspect the internal threads of regulator ﬁ  ing to ensure they are clean and dry. Install jet into the fuel elbow oriﬁ ce for LPG operation. See Figure 4. Reconnect and fully tighten the fuel inlet hose.

NOTE: Turn on fuel supply and check all fuel line

connections with soapy water before starting or pu ing engine/system into service.

Outlet pressure should be checked and if required, set at the secondary regulator to 4.0 to 5.0 PSI by qualiﬁ ed personnel.

NG Operation

Removal of jet from regulator ﬁ  ing is required for NG operation.

Switching from LPG to NG

NOTE: When switching from LPG to NG fuel, the ba ery must be temporarily disconnected for safety and to reset system.

Tanks must be removed from equipment before ﬁ lling.

NG Engines

NG from an approved system or source of supply can be used to operate this engine.

WARNING: Explosive Fuel!

Fuel Conversion

Some engines are equipped to convert between LPG and NG. The models with the ﬁ  ing and jet shown below should follow these instructions for conversion. Other metering valves should be installed following the instructions given by the equipment it powers. Shut oﬀ fuel supply before any servicing is performed.

NOTE: Engines with a DSAI system will have leads

located near the fuel regulator. Connect the leads for NG and leave disconnected for LPG.

Remove the LPG fuel jet from the regulator ﬁ  ing. Disconnect the hose, remove the jet from the oriﬁ ce (Figure 4), and reconnect the hose.

NOTE: Turn on fuel supply and check all fuel line

connections with soapy water before starting or pu ing engine/system into service.

Recommended fuel inlet pressure for NG systems is 11 in. water (engine oﬀ ). Reduced pressure could result in hard starting.

Figure 4. Fitting and Jet.

Model Designation

Model CH730 for example: C designates Command engine, H designates horizontal cranksha , and 730 indicates the numerical model designation.

Engine Identiﬁ cation Numbers

When ordering parts, or in any communication involving an engine, always give the Model, Speciﬁ cation, and Serial Numbers of the engine.

The engine identiﬁ cation numbers appear on a decal aﬃ xed to the engine shrouding. Include le er suﬃ xes, if there are any.

Emission Compliance Period

The Emission Compliance Period referred to on the Emission Control or Air Index label indicates the number of operating hours for which the engine has been shown to meet CARB emission requirements. The following table provides the Engine Compliance Period (in hours) associated with the category descriptor which may be found on the certiﬁ cation label.

CARB

Refer to certiﬁ cation label for engine displacement.

Exhaust Emission Control System for gaseous fuel models CH640, CH730, and CH740, is EM for U.S. EPA, California, and Europe.

Moderate 125 hours

Intermediate 250 hours

Extended 500 hours

Operating Instructions

Also read the operating instructions of the equipment this engine powers.

• Check that any clutches or transmissions are disengaged or placed in neutral. This is especially important on equipment with hydrostatic drive. The shi lever must be exactly in neutral to prevent resistance which could keep the engine from starting.

WARNING: Lethal Exhaust Gases!

Although LPG/NG burns more eﬃ ciently and emits less carbon monoxide than gasoline, some carbon monoxide is produced. Avoid inhaling exhaust gases, especially over prolonged periods of time. Do not allow engine to run una ended.

Cold Weather Starting Hints

1. Be sure to use the proper oil for the temperature expected. See Figure 2 on page 4.

2. Disengage all possible external loads.

3. Be sure the ba ery is in good condition. A warm ba ery has much more starting capacity than a cold ba ery.

Starting

1. Place the thro le control in the idle position. Place the choke control (if equipped) into the on position. See Figure 5.

Pre-Start Checklist

• Check oil level. Add oil if low. Do not overﬁ ll.

• Check fuel gauge on LPG tank. Tanks should be ﬁ lled to a speciﬁ c weight. To ensure safety and proper fuel system operation, tanks must not be overﬁ lled.

• Check fuel lines, regulator, and other system components for leaks. Do not start engine until leaks are eliminated.

• Check cooling air intake areas and external surfaces of engine. Make sure they are clean and unobstructed.

• Check that the air cleaner components and all shrouds, equipment covers, and guards are in place and securely fastened.

Figure 5. Optional Engine Mounted Throttle and Choke Controls.

2. Slowly turn the fuel valve on the LPG (propane) tank or the NG line (if equipped) to full open position.

3. Start the engine by activating the key switch. Release the switch as soon as the engine starts. Return choke to oﬀ position a er engine starts. On a cold engine, it may be necessary to leave choke partially on until engine begins to warm up.

NOTE: Do not crank the engine continuously

for more than 10 seconds at a time. If the engine does not start, allow a 60 second cool down period between starting a empts. Failure to follow these guidelines can burn out the starter motor.

NOTE: If the engine develops suﬃ cient speed to

disengage the starter but does not keep running (a false start), engine rotation must be allowed to come to a complete stop before a empting to restart the engine. If the starter is engaged while the ﬂ ywheel is rotating, the starter pinion and ﬂ ywheel ring gear may clash, resulting in damage to the starter.

If the starter does not turn the engine over, shut oﬀ starter immediately. Do not make further a empts to start the engine until the condition is corrected. Do not jump start using another ba ery (refer to Ba ery). See your Kohler Engine Service Dealer for trouble analysis.

NG Fueled Engines

1. Remove the load by disengaging all PTO driven a achments.

2. Turn fuel valve on NG line, if equipped, to full closed position and allow the engine to continue running until it runs out of fuel. Turn ignition switch to oﬀ position. Switching oﬀ the ignition prior to allowing the engine run out of fuel may create a backﬁ re.

Battery

A 12 volt ba ery is normally used. Refer to the operating instructions of the equipment this engine powers for speciﬁ c ba ery requirements.

If the ba ery charge is not suﬃ cient to crank the engine, recharge the ba ery (see page 12).

Operating

Angle of Operation

This engine will operate continuously at angles up to 25°. Check oil level to assure crankcase oil level is at the F mark on the dipstick.

Refer to the operating instructions of the equipment this engine powers. Because of equipment design or application, there may be more stringent restrictions regarding the angle of operation.

NOTE: Upon start-up, a metallic ticking may occur.

This is caused by hydraulic li er leakdown during storage. Run the engine for 5 minutes. The noise will normally cease in the ﬁ rst minute. If noise continues, run the engine at mid-thro le for 20 minutes. If noise persists, take the engine to your local Kohler Service outlet.

Stopping

LPG Fueled Engines

1. Remove the load by disengaging all PTO driven a achments.

2. Turn fuel valve on LPG tank to full closed position and allow the engine to continue running until it runs out of fuel. Turn ignition switch to oﬀ position.

In an emergency, move the thro le control to

stop or turn the ignition switch oﬀ .

NOTE: Backﬁ ring may occur when using the

emergency stop method!

NOTE: Do not operate this engine continuously

at angles exceeding 25° in any direction. Engine damage could result from insuﬃ cient lubrication.

Cooling

NOTE: If debris builds up on the ﬂ ywheel screen

or other cooling areas, stop the engine immediately and clean. Operating the engine with blocked or dirty air intake and cooling areas can cause extensive damage due to overheating.

WARNING: Hot Parts!

Engine Speed

NOTE: Do not tamper with the governor se ing

to increase the maximum engine speed. Overspeed is hazardous and will void the engine warranty. The maximum allowable high speed for these engines is 3750 RPM, no load.

Maintenance Instructions

service center.

For safety and health reasons, many states require special licensing or certiﬁ cation for servicing LPG/NG fuel systems. Check local and state regulations before choosing a repair establishment to perform fuel system repairs.

WARNING: Accidental Starts!

Disabling engine. Accidental starting can cause severe injury or death. Before working on the engine or equipment, disable the engine as follows: 1) Disconnect the spark plug lead(s). 2) Disconnect negative (-) ba ery cable from ba ery.

Before disconnecting the negative (-) ground cable, make sure all switches are oﬀ . If on, a spark will occur at the ground cable terminal which could cause an explosion if hydrogen gas or LPG/NG fuel vapors are present.

Maintenance Schedule

These required maintenance procedures should be performed at the frequency stated in the table. They should also be included as part of any seasonal tune-up.

Frequency Maintenance Required

Daily or Before

Starting Engine

Every 25 Hours

Every 100

Hours

Every 200

Hours

Annually or

Every 300

Hours

Annually or

Every 500

Hours

Every 1500

Hours

• Check fuel gauge on propane (LPG) tank.

• Check oil level.

• Check air cleaner for dirty1, loose, or damaged parts.

• Check air intake and cooling areas, clean as necessary1.

• Service precleaner element1.

• Replace air cleaner element1.

• Change oil.

• Remove cooling shrouds and clean cooling areas1.

• Check oil cooler ﬁ ns, clean as necessary (if equipped).

• Check spark plug condition and gap.

• Change oil ﬁ lter.

• Replace spark plugs.

• Check all lines (high pressure/vacuum) including ﬁ  ings for leaks.

• Have electric starter serviced2.

• Have lock-oﬀ /ﬁ lter serviced3.

• Have combustion deposits removed if using non-synthetic oil.

• Drain regulator of accumulated fuel deposits (Nikki regulators only).

• Have regulator disassembled, cleaned, and reset3.

• Have vaporizer disassembled, cleaned, and serviced3.

Perform these maintenance procedures more frequently under extremely dusty, dirty conditions.

Have a Kohler Engine Service Dealer perform this service.

Must be performed by an Authorized Kohler Engine Dealer or qualiﬁ ed LPG personnel only.

Check Oil Level

The importance of checking and maintaining the proper oil level in the crankcase cannot be overemphasized. Check oil BEFORE EACH USE as follows:

1. Make sure the engine is stopped, level, and is cool so the oil has had time to drain into the sump.

2. To keep dirt, debris, etc., out of the engine, clean the area around the dipstick before removing it.

Change Oil and Oil Filter

Change Oil

Change oil a er every 100 hours of operation. Reﬁ ll with service class SG, SH, SJ or higher oil as speciﬁ ed in the Viscosity Grades table (Figure 2) on page 4.

Change the oil while the engine is still warm. The oil will ﬂ ow more freely and carry away more impurities. Make sure the engine is level when ﬁ lling, checking, and changing the oil.

3. Remove the dipstick; wipe oil oﬀ . Reinsert the dipstick into the tube and press all the way down.

4. Remove the dipstick and check the oil level.

The oil level should be up to, but not over, the F

mark on the dipstick. See Figure 6.

F Mark

Operating

Range

Figure 6. Oil Level Dipstick.

5. If the level is low, add oil of the proper type, up to the F mark on the dipstick. (Refer to Oil Type on page 4.) Always check the level with the dipstick before adding more oil.

NOTE: To prevent extensive engine wear or

damage, always maintain the proper oil level in the crankcase. Never operate the engine with the oil level below the L mark or over the F mark on the dipstick.

Change the oil as follows (see Figure 7):

1. To keep dirt, debris, etc., out of the engine, clean the area around the oil ﬁ ll cap/dipstick before removing it.

2. Remove one of the oil drain plugs, oil ﬁ ll cap, and dipstick. Be sure to allow ample time for complete drainage.

3. Reinstall the drain plug. Make sure it is tightened to 13.6 N·m (10  . lb.) torque.

4. Fill the crankcase, with new oil of the proper type, to the F mark on the dipstick. Refer to Oil Type on page 4. Always check the level with the dipstick before adding more oil.

5. Reinstall the oil ﬁ ll cap and tighten securely. Reinstall dipstick.

NOTE: To prevent extensive engine wear or

damage, always maintain the proper oil level in the crankcase. Never operate the engine with the oil level below the L mark or over the F mark on the dipstick.

Oil Sentry

™

Some engines are equipped with an optional Oil Sentry™ switch. This switch is designed to prevent the engine from starting in a low oil or no oil condition. The 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.

NOTE: Make sure the oil level is checked BEFORE

EACH USE and is maintained up to the F mark on the dipstick. This includes engines equipped with Oil Sentry™.

Oil Filter

Engine Oil Drain Plug

Figure 7. Oil Drain Plug and Oil Filter.

Change Oil Filter

Replace the oil ﬁ lter at least every other oil change (every 200 hours of operation). Always use a genuine

Kohler oil ﬁ lter. Use chart below to determine part number to order.

Air Cleaner Cover

Air Cleaner Cover Knob

Oil Filter Part No.

12 050 01-S

52 050 02-S

Length

2-1/2"

3-3/8"

Replace the oil ﬁ lter as follows:

1. Drain the oil from the engine crankcase by removing one of the drain plugs and allowing ample time for complete drainage.

2. Before removing the oil ﬁ lter, clean the area around the oil ﬁ lter to keep dirt and debris out of the engine. Remove the old ﬁ lter. Wipe oﬀ the surface where the oil ﬁ lter mounts.

3. Place a new replacement ﬁ lter in a shallow pan with the open end up. Pour new oil of the proper type in through the threaded center hole. Stop pouring when the oil reaches the bo om of the threads. Allow a minute or two for the oil to be absorbed by the ﬁ lter material.

4. Apply a thin ﬁ lm of clean oil to the rubber gasket on the new ﬁ lter.

5. Install the new oil ﬁ lter to the ﬁ lter adapter or oil cooler. Refer to instructions on the oil ﬁ lter for proper installation.

Figure 8. Air Cleaner Housing Components.

Element Cover

Element Cover Nut

Element

Precleaner

Figure 9. Air Cleaner System Components.

Check the air cleaner daily or before starting the engine. Check for a buildup of dirt and debris around

the air cleaner system. Keep this area clean. Also check for loose or damaged components. Replace all bent or damaged air cleaner components.

6. Reinstall the drain plug. Make sure it is tightened to 13.6 N·m (10  . lb.) torque.

7. Fill the crankcase with new oil of the proper type to the F mark on the dipstick.

8. Test run the engine to check for leaks. Stop the engine, allow a minute for the oil to drain down, and recheck the level on the dipstick. Add more oil as necessary so the oil level is up to but not over the F mark on the dipstick.

Service Precleaner and Air Cleaner Element

This engine is equipped with a replaceable, high density paper air cleaner element. Most engines are also equipped with an oiled, foam precleaner which surrounds the paper element. See Figures 8 and 9.

NOTE: Operating the engine with loose or

damaged air cleaner components could allow unﬁ ltered air into the engine causing premature wear and failure.

Service Precleaner

If so equipped, wash and reoil the precleaner every 25 hours of operation (more o en under extremely dusty

or dirty conditions).

1. Loosen the cover retaining knob and remove the

cover.

2. Remove the precleaner from the paper element.

3. Wash the precleaner in warm water with detergent. Rinse the precleaner thoroughly until all traces of detergent are eliminated. Squeeze out excess water (do not wring). Allow the precleaner to air dry.

4. Saturate the precleaner with new engine oil. Squeeze out all excess oil.

5. Reinstall the precleaner over the paper element.

6. Reinstall the air cleaner cover. Secure cover with the cover retaining knob.

Clean Air Intake/Cooling Areas

To ensure proper cooling, make sure the ﬂ ywheel screen, cooling ﬁ ns, and other external surfaces of the engine are kept clean at all times.

7. When precleaner replacement is necessary order genuine Kohler parts. See chart below.

CH640 CH730 CH740

24 083 02-S 24 083 02-S 24 083 02-S 61 mm (2.4 in.)

- 24 083 05-S 24 083 05-S 71 mm (2.8 in.)

Service Paper Element

Every 100 hours of operation (more o en under extremely dusty or dirty conditions) replace the paper element.

1. Loosen the cover retaining knob and remove the air cleaner cover.

2. Remove the element cover nut, element cover, and paper element/precleaner.

3. Remove the precleaner (if so equipped) from the paper element and service as instructed above.

4. Do not wash the paper element or use pressurized air, as this will damage the element. Replace a dirty, bent, or damaged element with a genuine Kohler element. Handle new elements carefully; do not use if the sealing surfaces are bent or damaged.

5. When servicing the air cleaner, check the air cleaner base. Make sure it is secured and not bent or damaged. Also, check the element cover for damage or improper ﬁ t. Replace all damaged air cleaner components.

Height of

Precleaner

Every 100 hours of operation (more o en under extremely dusty, dirty conditions), remove the blower housing and other cooling shrouds. Clean the cooling ﬁ ns and external surfaces as necessary. Make sure the cooling shrouds are reinstalled.

NOTE: Operating the engine with a blocked

ﬂ ywheel screen, dirty or plugged cooling ﬁ ns, and/or cooling shrouds removed, will

cause engine damage due to overheating.

Ignition System

CH640 and CH730 engines are equipped with an electronic CDI system. CH740 engines are equipped with an electronic DSAI system. Other than periodically checking/replacing the spark plugs, no maintenance, timing, or adjustments are necessary or possible with these systems.

NOTE: Engines with a DSAI system will have leads

located near the fuel regulator. Connect the leads for NG and leave disconnected for LPG.

In the event starting problems should occur which are not corrected by replacing the spark plugs, see your Kohler Engine Service Dealer for trouble analysis.

Check Spark Plugs

Every 100 hours of operation, remove the spark plugs, check condition, and reset the gap or replace with new plugs as necessary. Every 300 hours or annually replace the spark plugs. Refer to the chart below for replacement spark plugs. Equivalent alternate brand plugs can also be used.

NOTE: Before air cleaner reassembly make sure

rubber seal is in position around stud. Inspect, making sure it is not damaged and seals with the element cover.

6. Reinstall the paper element, precleaner, element cover, element cover nut, and air cleaner cover. Secure cover with cover retaining knob.

7. When element replacement is necessary order genuine Kohler parts. See chart below.

CH640 CH730 CH740

24 083 08-S 47 083 03-S 24 083 08-S 66 mm (2.6 in.)

- 24 083 03-S 24 083 09-S 74 mm (2.9 in.)

Height

of Element

Kohler

Model

CH640

CH730

CH740

1. Before removing the spark plug, clean the area around the base of the plug to keep dirt and debris out of the engine.

2. Remove the plug and check its condition. Replace the plug if worn or reuse is questionable.

Part No. Champion©

25 132 14-S XC12YC 0.51 (0.020)

12 132 02-S 25 132 14-S

12 132 02-S 25 132 12-S 25 132 14-S

RC12YC XC12YC

RC12YC

3071

XC12YC

Gap

mm (in.)

0.76 (0.030)

NOTE: Do not clean the spark plugs in a machine

using abrasive grit. Some grit could remain in the spark plug and enter the engine causing extensive wear and damage.

3. Check the gap using a wire feeler gauge. Adjust the gap according to the chart by carefully bending the ground electrode. See Figure 10.

Wire Gauge

Spark Plug

Fuel Line

These engines use low permeation rated fuel lines, certiﬁ ed to comply with California and U.S. EPA evaporative emission requirements. Fuel lines that do not meet these requirements may not be used. Order replacement hose through a Kohler Service Center.

Carburetor Troubleshooting and Adjustments

In compliance with government emission standards, the carburetor and the regulator are calibrated and preset to deliver the correct fuel-to-air mixture to the engine under all operating conditions and cannot be adjusted, except for low idle speed. Carburetor servicing is to be performed by an authorized Kohler Engine Service Dealer only. See Figure 11.

Ground Electrode

Figure 10. Servicing Spark Plug.

4. Reinstall the spark plug into the cylinder head. Torque the spark plug to 24.4-29.8 N·m (18-22  . lb.).

Gap

Battery Charging

WARNING: Explosive Gas!

Charging of ba ery should be performed as outlined by the original equipment manufacturer (OEM) in their operator's manual.

Fuel Filter

The ﬁ lter of the LPG/NG fuel system is an integral part within the lock-oﬀ /ﬁ lter assembly. All service relating to the lock-oﬀ /ﬁ lter is to be performed by an authorized Kohler Engine Service Dealer or qualiﬁ ed LPG personnel only. Servicing of ﬁ lter is recommended every 500 hours.

Low Idle Speed Adjusting Screw

Figure 11.

LPG Regulator

In compliance with government emission standards, the regulator is preset at the factory to provide the proper supply of fuel. No adjustment or rese ing of regulator is to be made. All service relating to the regulator must be performed by an authorized Kohler Engine Service Dealer or qualiﬁ ed LPG personnel only.

Over time, fuel deposits can accumulate inside the regulator. Removing these deposits is recommended (Nikki regulators only) every 500 operating hours, or annually, whichever comes ﬁ rst.

Nikki Regulators Every 500 hours/annually drain regulator:

1. Turn fuel supply valve oﬀ , run engine out of fuel, and turn oﬀ ignition switch.

2. Disconnect and ground the spark plug leads.

3. Remove the 1/8" pipe plug from the bo om of regulator. Remove any accumulated deposits. See Figure 12.

Regulator Drain Plug

Figure 12. Nikki Regulator Drain Plug.

4. Reinstall plug using Teﬂ on® pipe sealant (not Teﬂ on® tape) on threads and tighten securely. If required, a replacement plug is available as Kohler Part No. 25 139 60-S.

All Regulators Every 1500 Hours:

Complete cleaning (disassembling, servicing, and rese ing) of regulator at 1500 hour intervals is recommended. As all adjustments and se ings must be reset using speciﬁ c test equipment, this must be performed by an authorized Kohler Engine Service Dealer or qualiﬁ ed LPG personnel only.

Lock-Off/Filter Assembly

This opens, closes, and ﬁ lters the liquid fuel ﬂ ow from the supply tank before reaching the vaporizer. Servicing, if required, is to be performed by an authorized Kohler Engine Service Dealer or qualiﬁ ed LPG personnel only. See Figures 13 and 14.

Vaporizer

The vaporizer changes the Liqueﬁ ed Petroleum (LPG) from the supply tank to a gaseous/vapor state. Cleaning should be performed on a regular basis, more frequently under dusty or dirty conditions. The vaporizer should be disassembled, cleaned, and serviced using a rebuild kit every 1500 hours by an authorized Kohler Engine Service Dealer or qualiﬁ ed LPG personnel only.

LPG Carburetor

Fuel Delivery Line

Vacuum Line

Dry Gas Regulator

Propane Supply Tank (Liquid Withdrawal)

Figure 13. Schematic Showing Components of LPG System.

Vaporizer

High Pressure Line

Lock-Off/Filter (12 Volt DC)

Carburetor

Fuel Delivery Line

To Natural Gas Source

Lock-Off/Filter (12 Volt DC)

Vacuum Line

Dry Gas Regulator

Figure 14. Schematic Showing Components of NG System.

Leakage Check/Testing

• Check to make sure the fuel valve on LPG tank is

Every 500 hours or annually. With LPG tank valve fully opened, engine not running, turn key switch ON. Check all LPG system connections and lines for leaks

• Check gauge on LPG tank to make sure pressure

using soapy water. Any leakage must be corrected before restarting engine. Have service performed by an authorized Kohler Engine Service Dealer or qualiﬁ ed LPG personnel only.

If a er checking the items listed above, the engine is hard to start, runs roughly, or stalls at low idle speed, qualiﬁ ed fuel system servicing may be necessary.

Troubleshooting - Fuel Related

If engine problems are experienced that appear to be

Contact your nearest authorized Kohler Engine Service Dealer for further assistance.

fuel system related, check the following areas before seeking service assistance.

Troubleshooting

When troubles occur, be sure to check the simple

• Make sure the LPG tank is properly ﬁ lled (never to more than 80 percent of total capacity). An air space must be present in the tank to allow fuel to expand.

• Make sure the air cleaner element is clean and all air cleaner components are fastened securely.

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 common causes of engine troubles are listed in the following table.

Do not a empt to service or replace major engine components, or any items that require special timing or adjustment procedures. Have your Kohler Engine

• Check for loose, kinked, or cracked vacuum lines

Service Dealer do this work.

causing regulator not to open.

fully open.

is suﬃ cient to open the regulator.

Possible Cause Problem No Fuel

Will Not Start • •••••••• Hard Starting •••••••••• Stops Suddenly • •••••• • Lacks Power ••••••••• Operates Erratically •••• •••• Knocks or Pings •••••• Skips or Misﬁ res •••• ••• Backﬁ res •• ••• Overheats ••••••• • High Fuel Consumption ••

Improper

Fuel

Dirt In

Fuel Line

Dirty/

Restricted

Lock-off

Fuel Filter

Dirty

Flywheel

Screen

Incorrect Oil Level

Engine

Overloaded

Dirty Air

Cleaner

Faulty Spark

Plug

Dirty/

Restricted

Regulator

Storage

When the engine is not in use, use the following storage procedure. Federal, state, or local laws governing LPG fuel tank storage may also apply. Follow the applicable storage laws.

1. Clean the exterior surfaces of the engine.

Parts Ordering

The engine Speciﬁ cation, Model, and Serial Numbers are required when ordering replacement parts from your Kohler Engine Service Dealer. These numbers are found on the identiﬁ cation plate which is aﬃ xed to the engine shrouding. Include le er suﬃ xes if there are any. See Engine Identiﬁ cation Numbers on page 6.

2. Change the oil and ﬁ lter while the engine is still warm from operation. See Change Oil and Oil Filter on page 9.

3. Turn valve on LPG tank oﬀ and run engine until the fuel system is empty. Turn ignition key switch oﬀ . Separate LPG tank from the unit and store separately in an area designated for safe LPG tank storage.

4. Remove the spark plugs. Add one tablespoon of engine oil into each spark plug hole. Install the plugs, but do not connect the plug leads. Crank the engine two or three revolutions.

5. Store the engine in a clean, dry place. Store the fuel tank in a designated safe LPG storage area at all times when not in use.

Speciﬁ cations

Bore

Model

CH640 77 (3.03) 67 (2.64) 624 (38)

CH730 83 (3.27) 67 (2.64) 725 (44)

CH740 83 (3.27) 67 (2.64) 725 (44)

*approximate, determined by oil ﬁ lter and oil cooler used.

mm (in.)

Stroke

mm (in.)

Displacement

cm3 (in.3)

Max. Torque

N·m (ft. lb.)

44 (32)

@ 2500 RPM

54 (39.5)

@ 2400 RPM

57 (42.3)

@ 2400 RPM

Always insist on genuine Kohler parts. All genuine Kohler parts meet strict standards for ﬁ t, reliability, and performance.

Major Repair

Major repair information is available in Kohler Engine Service Manuals. This type of repair generally requires the services of a trained mechanic and the use of special tools and equipment. Kohler Engine Service Dealers have the facilities, training, and genuine Kohler replacement parts necessary to perform this service.

For the nearest Sales & Service location:

• visit our website www.kohlerengines.com

• call 1-800-544-2444 (U.S. & Canada)

• look in the yellow pages under Engines-Gasoline

Compression

Ratio

8.5:1 41 (90)

9.0:1 43 (94)

Weight kg (lb.) Lubrication

Full Pressure

w/full Flow

Filter

Oil Capacity

(w/ﬁ lter)*

1.6-1.8 L (1.7-1.9

U.S. qt.)

Exhaust Emission Control System for gaseous fuel models CH640, CH730, and CH740, is EM for U.S. EPA, California, and Europe.

LIMITED 2 YEAR COMMAND ENGINE WARRANTY

Kohler Co. warrants to the original consumer that each new Command engine sold by Kohler Co. will be free from manufacturing defects in materials or workmanship in normal service for a period of two (2) years from date of purchase, provided it is operated and maintained in accordance with Kohler Co.’s instructions and manuals.

Our obligation under this warranty is expressly limited, at our option, to the replacement or repair at Kohler Co., Kohler, Wisconsin 53044, or at a service facility designated by us of such parts as inspection shall disclose to have been defective.

EXCLUSIONS: Mufﬂ ers on engines used commercially (non-residential) are warranted for one (1) year from date of purchase, except catalytic mufﬂ ers, which are warranted for two (2) years.

This warranty does not apply to defects caused by casualty or unreasonable use, including faulty repairs by others and failure to provide reasonable and necessary maintenance.

The following items are not covered by this warranty: Engine accessories such as fuel tanks, clutches, transmissions, power-drive assemblies, and batteries, unless supplied or installed by

Kohler Co. These are subject to the warranties, if any, of their manufacturers. KOHLER CO. AND/OR THE SELLER SHALL NOT BE LIABLE FOR SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL

DAMAGES OF ANY KIND, including but not limited to labor costs or transportation charges in connection with the repair or replacement of defective parts.

IMPLIED OR STATUTORY WARRANTIES, INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE EXPRESSLY LIMITED TO THE DURATION OF THIS WRITTEN WARRANTY. We make no other express warranty, nor is any one authorized to make any on our behalf.

Some states do not allow limitations on how long an implied warranty lasts, or the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you.

This warranty gives you speciﬁ c legal rights, and you may also have other rights which vary from state to state. TO OBTAIN WARRANTY SERVICE:

Purchaser must bring the engine to an authorized Kohler service facility. To locate the nearest facility, visit our website, www.kohlerengines.com, and click on SALES AND SERVICES to use the locator function, consult your Yellow Pages or telephone 1-800-544-2444.

ENGINE DIVISION, KOHLER CO., KOHLER, WISCONSIN 53044

KOHLER CO.

FEDERAL AND CALIFORNIA EMISSION CONTROL SYSTEMS

LIMITED WARRANTY

SMALL OFF-ROAD AND CLASS 1 LSI ENGINES

The U.S. Environmental Protection Agency (EPA), the California Air Resources Board (CARB), and Kohler Co. are pleased to explain the 2011 and later Federal and California Emission Control Systems Warranty on your oﬀ -road equipment engine. “Emissions“ means both exhaust and evaporative emissions. For California, small oﬀ -road engines, and Class 1 LSI (Large Spark Ignited engines at or below 1.0 liter) must be designed, built and equipped to meet the state’s stringent anti-smog standards. In other states, engines must be designed, built and equipped, to meet the U.S. EPA regulations for small non-road engines. The engine must be free from defects in materials and workmanship which cause it to fail to conform with U.S. EPA standards for the ﬁ rst two years of engine use from the date of sale to the ultimate purchaser. Kohler Co. must warrant the emission control system on the engine for the period of time listed above, provided there has been no abuse, neglect or improper maintenance.

The emission control system may include parts such as the carburetor or fuel injection system, the ignition system, and catalytic converter. Also included are the hoses, belts and connectors and other emission related assemblies.

Where a warrantable condition exists, Kohler Co. will repair the engine at no cost, including diagnosis (if the diagnostic work is performed at an authorized dealer), parts and labor.

MANUFACTURER’S WARRANTY COVERAGE

Small oﬀ -road engines and Class 1 LSI engines are warranted for two years in California and other states. If any emission related part on the engine is defective, the part will be repaired or replaced by Kohler Co. free of charge.

OWNER’S WARRANTY RESPONSIBILITIES

(a) The engine owner is responsible for the performance of the required maintenance listed in the owner’s manual. Kohler Co.

recommends that you retain all receipts covering maintenance on the engine, but Kohler Co. cannot deny warranty solely for the lack of receipts or for your failure to assure that all scheduled maintenance was performed.

(b) Be aware, however, that Kohler Co. may deny warranty coverage if the engine or a part has failed due to abuse, neglect, improper

maintenance or unapproved modiﬁ cations.

(c) For warranty repairs, the engine must be presented to a Kohler Co. service center as soon as a problem exists. Call 1-800-544-2444

or access our web site at: www.kohlerengines.com, for the names of the nearest service centers. The warranty repairs should be completed in a reasonable amount of time, not to exceed 30 days.

If you have any questions regarding warranty rights and responsibilities, you should contact Kohler Co. at 1-920-457-4441 and ask for an Engine Service representative.

COVERAGE

Kohler Co. warrants to the ultimate purchaser and each subsequent purchaser that the engine will be designed, built and equipped, at the time of sale, to meet all applicable regulations. Kohler Co. also warrants to the initial purchaser and each subsequent purchaser, that the engine is free from defects in materials and workmanship which cause the engine to fail to conform with applicable regulations for a period of two years.

Small oﬀ -road engines and Class 1 LSI engines are warranted for two years in California. EPA requires manufacturers to warrant engines for two years in all other states. These warranty periods will begin on the date the engine is purchased by the initial purchaser. If any emission related part on the engine is defective, the part will be replaced by Kohler Co. at no cost to the owner. Kohler Co. is liable for damages to other engine components caused by the failure of a warranted part still under warranty.

Kohler Co. shall remedy warranty defects at any authorized Kohler Co. engine dealer or warranty station. Warranty repair work done at an authorized dealer or warranty station shall be free of charge to the owner if such work determines that a warranted part is defective.

Continued on next page.

Listed below are the parts covered by the Federal and California Emission Control Systems Warranty. Some parts listed below may require scheduled maintenance and are warranted up to the ﬁ rst scheduled replacement point for that part. The warranted parts include the following if they were present in the engine purchased:

• Oxygen sensor (if equipped) • Ignition module(s) with high tension lead

• Intake manifold (if equipped) • Gaseous fuel regulator (if equipped)

• Exhaust manifold (if equipped) • Electronic control unit (if equipped)

• Catalytic muﬄ er (if equipped) • Carburetor or fuel injection system

• Thermal reactor muﬄ er (if equipped) • Fuel metering valve (if equipped)

• Fuel lines, fuel line ﬁ  ings and clamps (if equipped) • Air ﬁ lter, fuel ﬁ lter, and spark plugs (only

• Spark advance module (if equipped) to ﬁ rst scheduled replacement point)

• Crankcase breather • Evaporative System (if equipped)

• Air Injection System (if equipped) - Canister (if equipped)

- Air pump or pulse valve assembly (if equipped) - Canister ﬁ lter (if equipped)

- Control/distribution valve (if equipped) - Vapor hose (if equipped)

- Distribution manifold (if equipped) - Oriﬁ ce connector (if equipped)

- Air hoses (if equipped) - Fuel tank (if equipped)

- Vacuum lines (if equipped) - Fuel cap (if equipped)

- Primer bulb canister (if equipped)

LIMITATIONS

This Emission Control Systems Warranty shall not cover any of the following: (a) repair or replacement required because of misuse or neglect, improper maintenance, repairs improperly performed or replacements

not conforming to Kohler Co. speciﬁ cations that adversely aﬀ ect performance and/or durability and alterations or modiﬁ cations not recommended or approved in writing by Kohler Co.,

(b) replacement of parts and other services and adjustments necessary for required maintenance at and a er the ﬁ rst scheduled

replacement point,

(d) diagnosis and inspection fees that do not result in eligible warranty service being performed, and

(e) any add-on or modiﬁ ed part, or malfunction of authorized parts due to the use of add-on or modiﬁ ed parts.

MAINTENANCE AND REPAIR REQUIREMENTS

The owner is responsible for the proper use and maintenance of the engine. Kohler Co. recommends that all receipts and records covering the performance of regular maintenance be retained in case questions arise. If the engine is resold during the warranty period, the maintenance records should be transferred to each subsequent owner. Kohler Co. reserves the right to deny warranty coverage if the engine has not been properly maintained; however, Kohler Co. may not deny warranty repairs solely because of the lack of repair maintenance or failure to keep maintenance records.

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 service center. Any replacement part or service that is equivalent in performance and durability may be used in non-warranty maintenance or repairs, and shall not reduce the warranty obligations of the engine manufacturer.

FOR SALES AND SERVICE INFORMATION IN U.S. AND CANADA, CALL 1-800-544-2444

FORM NO.: 24 590 18 Rev. B ISSUED: 10/10 REVISED: 4/11

Kohler CH640, CH730, CH740 Owner's Manual

Specifications and Main Features

Frequently Asked Questions

User Manual