5. FUEL SYSTEM
5-3
SUPER8 50
TROUBLESHOOTING
Engine is hard to start Misfiring during acceleration
• No spark at plug (
Ö
Section 15) • Faulty ignition system
• Compression too low • Lean mixture
• No fuel to carburetor • Faulty accelerating pump
−Clogged fuel filter Engine idles roughly, stalls or runs poorly
−Restricted fuel line • Clogged fuel system
−Faulty float valve • Ignition malfunction
−Incorrectly adjusted float level • Rich or lean mixture
• Engine flooded with fuel • Contaminated fuel
−Clogged air cleaner • Intake air leak
−Fuel overflowing • Incorrect idle speed
• Intake air leak • Incorrectly adjusted pilot screw
• Contaminated fuel • Clogged idle system or auto bystarter passages
• Faulty auto bystarter • Incorrectly adjusted float level
• Clogged idle system or auto bystarter passages Lean mixture
Rich mixture • Clogged fuel jets
• Faulty auto bystarter • Faulty float valve
• Faulty float valve • Float level too low
• Float level too high • Clogged fuel system
• Clogged air jets • Intake air leak
• Dirty air cleaner • Improper vacuum piston operation
• Flooded carburetor • Improper throttle operation
Backfiring at deceleration
• Lean mixture in idle system
• Improper air cut-off valve operation