CH18, CH20, CH23, CH25, CH640, CH730, CH740 Service Manual

1 CH18, CH20, CH23, CH25, CH640, CH730, CH740 Liquefi ed Petroleum Gas (LPG) or LPG/Natural Gas (NG) FueledService Manual2 Safety3 Maintenance5 Specifi cations13 Tools and Aids16 Troubleshooting20 Air Cleaner/Intake21 Fuel System30 Governor System32 Lubrication System34 Electrical System50 Starter System57 Disassembly/Inspection and Service72 ReassemblyIMPORTANT: 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 690 30 Rev. 690 30 Rev. PRECAUTIONS WARNING: A hazard that could result in death, serious injury, or substantial property damage.

2 CAUTION: A hazard that could result in minor personal injury or property : is used to notify people of important installation, operation, or maintenance information. WARNINGE xplosive Fuel can cause fi res and severe a gaseous odor is detected, ventilate area and contact an authorized Service is extremely fl ammable and is heavier than air and tends to settle in low areas where a spark or fl ame 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 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 safety of persons in ensure personal safety, installation and repair of LPG/NG fuel supply systems must be performed only by qualifi ed LPG/NG system technicians.

3 Improperly installed and maintained LPG/NG equipment could cause fuel supply system or other components to malfunction, causing gas federal, state and local laws governing LPG/NG fuel, storage, and systems. WARNINGR otating Parts can cause severe away while engine is in hands, feet, hair, and clothing away from all moving parts to prevent injury. Never operate engine with covers, shrouds, or guards removed. WARNINGC arbon Monoxide can cause severe nausea, fainting or inhaling exhaust exhaust gases contain poisonous carbon monoxide. Carbon monoxide is odorless, colorless, and can cause death if inhaled. WARNINGA ccidental Starts can cause severe injury or and ground spark plug lead(s) before working on engine or equipment, disable engine as follows: 1) Disconnect spark plug lead(s).

4 2) Disconnect negative ( ) battery cable from 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 LPG/NG fuel vapors are present. WARNINGHot Parts can cause severe not touch engine while operating or just after operate engine with heat shields or guards removed. WARNINGC leaning Solvents can cause severe injury or only in well ventilated areas away from ignition cleaners and solvents are extremely fl ammable. Follow cleaner manufacturer s warnings and instructions on its proper and safe use.

5 Never use gasoline as a cleaning agent. CAUTIONE lectrical Shock can cause not touch wires while engine is running. CAUTIOND amaging Crankshaft and Flywheel can cause personal improper procedures can lead to broken fragments. Broken fragments could be thrown from engine. Always observe and use precautions and procedures when installing fl ywheel. CAUTIONF ailure to utilize or reassemble debris screen as designed could result in debris screen failure and serious personal 690 30 Rev. INSTRUCTIONS WARNINGB efore working on engine or equipment, disable engine as follows: 1) Disconnect spark plug lead(s). 2) Disconnect negative ( ) battery cable from disconnecting negative ( ) ground cable, make sure all switches are OFF.

6 If ON, a spark will occur at ground cable terminal which could cause an explosion if hydrogen gas or LPG/NG fuel vapors are Starts can cause severe injury or and ground spark plug lead(s) before 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 SCHEDULEE very 25 Hours1 Service precleaner Cleaner/IntakeEvery 100 Hours1 Check oil cooler fi ns, clean as necessary (if equipped).Air Cleaner/Intake Change System Replace air cleaner Cleaner/Intake Remove cooling shrouds and clean cooling Cleaner/IntakeEvery 200 Hours1 Change oil fi SystemEvery 500 Hours or Annually1 Check all lines (high pressure/vacuum)

7 Including fi ttings for System Drain regulator of accumulated fuel System Replace spark plugs and set SystemEvery 500 Hours or Annually1,2 Have lock-off/fi lter System Have combustion deposits removed if using non-synthetic 1500 Hours1,2 Have regulator disassembled, cleaned, and System Have vaporizer disassembled, cleaned, and System1 Perform these procedures more frequently under severe, dusty, dirty Must be performed by a Kohler authorized dealer or qualifi ed LPG personnel PARTSK ohler genuine Service parts can be purchased from Kohler authorized dealers. To fi nd a local Kohler authorized dealer visit or call 1-800-544-2444 ( and Canada).

8 Maintenance424 690 30 Rev. RECOMMENDATIONSS ynthetic oil is recommended for use in LPG/NG fueled engines. Non-synthetic oil must be low ash* rated oil. Oils (including synthetic) must meet API (American Petroleum Institute) Service class SG, SH, SJ, or SL. Select viscosity based on air temperature at time of operation as shown in table below.*Low ash is defi ned as less than 1% sulfated ash. FUEL RECOMMENDATIONS WARNINGE xplosive Fuel can cause fi res and severe a gaseous odor is detected, ventilate area and contact an authorized Service is extremely fl ammable and is heavier than air and tends to settle in low areas where a spark or fl ame could ignite gas.

9 Do not start or operate this engine in a poorly ventilated area where leaking gas could accumulate and endanger safety of persons in 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 safety of persons in 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 federal, state and local laws governing LPG/NG fuel, storage, and engine is certifi ed to operate on LPG or EnginesLPG from an appropriate LPG fuel tank (supplied separately) is required to operate this EnginesNG from an approved system or source of supply can be used to operate this engine will be out of Service for 2 months or more follow procedure Change oil while engine is still warm from operation.

10 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 Disconnect negative ( ) battery cable. 3. Separate LPG tank from unit and store separately in an area designated for safe LPG tank Store engine in a clean, dry cations524 690 30 Rev. DimensionsDimensions in millimeters. Inch equivalents shown in [ ].Specifi cations624 690 30 Rev. IDENTIFICATION NUMBERSK ohler engine identifi cation numbers (model, specifi cation and serial) should be referenced for effi cient repair, ordering correct parts, and engine .. CH640 Command EngineHorizontal ShaftNumerical DesignationSpecifi cation.