KYMCO MOVIE 125 Manual page 57

5
. FUEL SYSTEM
TROUBLESHOOTING
Engine is hard to start
• No spark at plug
• Compression too low
• No fuel to carburetor
-Clogged fuel filter
-Restricted fuel line
-Faulty float valve
-Incorrectly adjusted float level
• Engine flooded with fuel
-Clogged air cleaner
-Fuel overflowing
• Intake air leak
• Contaminated fuel
• Faulty auto bystarter
• Clogged idle system or auto bystarter passages
Rich mixture
• Faulty auto bystarter
• Faulty float valve
• Float level too high
• Clogged air jets
• Dirty air cleaner
• Flooded carburetor
Backfiring at deceleration
• Improper air cut-off valve operation
• Lean mixture in idle system
Misfiring during acceleration
• Faulty ignition system
• Lean mixture
Engine idles roughly, stalls or runs poorly
• Clogged fuel system
• Ignition malfunction
• Rich or lean mixture
• Contaminated fuel
• Intake air leak
• Incorrect idle speed
• Incorrectly adjusted pilot screw
• Clogged idle system or auto bystarter passages
• Incorrectly adjusted float level
Lean mixture
• Clogged fuel jets
• Faulty float valve
• Float level too low
• Clogged fuel system
• Intake air leak
• Improper vacuum piston operation
• Improper throttle operation
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