Basic Troubleshooting

Engine Will Not Crank

• Battery lead connections loose
• Battery charge low or discharged
• Battery amperage too low
• Starting leads reversed
• Fuse in wiring harness blown
• Key switch wired wrong
• Safety switch malfunctioning
• Wiring harness wired wrong
• Wiring harness incorrect
• Starting cable connectors loose
• Connectors corroded or worn
• Starter/solenoid malfunctioning
• Electric clutch air gap wrong
• Drive pulley against engine power take-off (PTO) face
• Drive belt wedged between idler pulley
• Drive belt wedged between belt guide
• Drive belt tension adjusted too tight
• Starting torque too high for starter
• Automatic compression release inoperative
• Combustion chamber flooded with oil/gas
• No oil in crankcase causing seized rod
• Drive shaft coupling forcing engine shaft against internal thrust face eliminating crankshaft end play
• Transmission brakes too tight

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Cranks - Will Not Start

• Fuel tank empty
• Fuel hose kinked, pinched
• Fuel filter clogged
• Fuel valve shut off
• Fuel solenoid inoperative
• LPG regulator not opening
• Water in fuel, stale fuel
• Wrong type fuel (diesel)
• Throttle control in stop position
• Choke not fully closed
• Choke on, flooding hot engine
• Power take-off (PTO) clutch on
• Safety interlocks inoperative
• Spark plug wire disconnected
• Spark plug improperly gapped
• Wrong type of spark plug
• Wiring harness not connected
• Wiring broken, loose or wrong
• Transmission not in neutral
• Electrical clutch not adjusted
• Cranking speed too slow to start
• Spark plug loose
• Low or no compression

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Runs Rough on Low & Will Not Accelerate

• Spark plug gap incorrect
• Engine not properly warmed up
• Running out of fuel
• Low idle set too low (below 1000 RPM)
• Low idle fuel setting too lean
• Electric clutch dragging
• Parasitic load on power take-off (PTO) shafts
• Crankshaft end play zeroed by drive

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Backfires on Full Throttle

• Water-contaminated fuel
• Low on fuel
• Fuel mixture too rich or too lean
• Carburetor fuel solenoid shorting
• Throttle or choke improperly set
• Dirty carburetor needs cleaning
• Kill switch contacting intermittently
• Key switch malfunctioning
• Safety interlock(s) malfunctioning
• Faulty fuse in unit control box
• Leaking, worn valves in engine

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Electrical System Problems

Charges and Gradually Discharges

• Improper ground causing battery to lose charge when accessories activated
• Faulty battery will not hold charge

Will Not Charge

• Rectifier-regulator failed
• Rectifier-regulator not grounded
• Flywheel magnet not charged
• Fuse blown or circuit breaker open

Blowing Fuses

• Rectifier-regulator burned out
• Leads pinched causing shorting
• Alternator stator shorted

Electric Clutch Will Not Engage

• Wrong rectifier-regulator used
• Wiring wrong or not grounded

Engine Runs on When Switched Off

• Ignition grounding terminal or ground lead not connected at ignition module
• Faulty switch

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Engine Not Running (After Hot Test)

Smoke rises out of top of horizontal-shaft engine or flywheel screen on vertical-shaft engine.

• Paint or oil burn off
• Battery cables reversed causing charging stator to short out
• Defective rectifier-regulator causing charging stator to short out
• Electric clutch - no running clearance

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Stops on High Idle

• Running out of fuel
• Running out of oil in crankcase
• Carburetor solenoid malfunctioning
• Key switch malfunctioning
• Safety interlocks malfunctioning
• Spark plug lead loose
• Fuse blown in control box
• Carburetor out of adjustment
• LPG regulator malfunctioning
• Loss of vacuum to LPG regulator
• Tight drive belt causing crankshaft bearing to seize

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Hot - Will Not Restart

• Overheated - clogged cooling fins
• Overheated - blocked shrouding
• Closed choke flooding engine
• Throttle not in midway position
• Throttle left in stop position
• Carburetor solenoid malfunctioning
• Fouled spark plug
• Kill lead shorting out
• Ran out of fuel
• Lost compression
• LPG regulator not functioning
• Vacuum too low to open LPG regulator

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Cannot Reach High Idle RPM (No Load)

• Choke not completely opened
• Throttle control cable clip loose
• Throttle control improperly installed
• Fuel filter or line clogged
• Fuel inlet line too small
• Fuel running low
• Fuel tank too far from engine
• Fuel pump malfunctioning
• Gravity feed tank below carburetor
• Foreign material in carburetor
• Carburetor out of adjustment
• Spark plug gapped wrong causing intermittent firing
• Drive system binding

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Starting Hints - Command Retractable

Dual Control Cable Instructions

• Close choke
• Set throttle to full
• Pull starter rope to set engine on compression
• Return starter rope, then give a full, steady pull
• When engine starts, return choke to full open immediately
• Position throttle control to desired setting

Single Control Cable Instructions

• Move throttle/choke lever to choke position
• Pull starter rope to set engine on compression
• Return starter rope, then give a full, steady pull
• When engine starts, move the control lever to the desired setting

If troubles persist after checking all possible causes listed in the foregoing categories or you are unable to detect the cause, call the Kohler Co. (920-457-4441) and ask for Engine Customer Service.

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