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TROUBLESHOOTING
Poor performance (driveability) and poor fuel economy
Backfiring or misfiring during acceleration
Afterburn when engine braking is used
Engine stalls, hard to start, rough idling
Engine cranks but won’t start
Lean mixture
Rich mixture
FUEL SYSTEM
5-2
No fuel in tank
No fuel to carburetor
Clogged fuel strainer
Clogged fuel line
Clogged fuel tank breather tube
Misadjusted fuel level
Too much fuel getting to the engine
Clogged air cleaner
Flooded carburetor
Intake air leak
Contaminated/deteriorated fuel
Clogged jets
Clogged starting enrichment valve circuit
Improper starting enrichment valve operation
Improper throttle operation
No spark at plug (faulty ignition system
section 18)
Clogged fuel jets
Faulty float valve
Float level too low
Restricted fuel line
Clogged carburetor air vent tube
Restricted fuel tank breather tube
Intake air leak
Faulty vacuum piston
Faulty throttle valve
Starting enrichment valve open (ON)
Clogged air jets
Faulty float valve
Float level too high
Dirty air cleaner
Worn jet needle or needle jet
Faulty vacuum piston
Restricted fuel line
Fuel mixture too lean/rich
Contaminated/deteriorated fuel
Clogged jets
Intake air leak
Misadjusted idle speed
Misadjusted pilot screw
Misadjusted float level
Restricted fuel tank breather tube
Clogged air cleaner
Clogged slow circuit
Clogged starting enrichment valve circuit
Faulty ignition system (section 18)
Lean mixture
Faulty ignition system (section 18)
Clogged fuel system
Faulty ignition system (section 18)
Lean mixture in slow circuit
Faulty air cut-off valve
Faulty ignition system (section 18)
03/01/08 09:25:52 61HN400C_013