Fuel System Troubleshooting - Honda VTR1000F Service Manual

TROUBLESHOOTING
Engine cranks but won't start
• No fuel in tank
• No fuel to carburetor
-Clogged fuel strainer
-Clogged fuel line
-Clogged fuel valve vacuum tube
-Disconnected fuel valve vacuum tube
-Clogged fuel tank breather tube
• Too much fuel getting to the engine
-Clogged air cleaner
- Flooded carburetor
• Intake air leak
• Contaminated/deteriorated fuel
• Improper choke operation
• Improper throttle operation
• No spark at plug (faulty ignition system-section 17)
Lean mixture
• 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
Rich mixture
• Starting enrichment valve open
• Clogged air jets
• Faulty float valve
• Float level too high
• Dirty air cleaner
• Faulty vacuum piston
FUELSVSTEM
Engine stalls, hard to start, rough idling
• Restricted fuel line
• Fuel mixture too lean/rich
• Contaminated/deteriorated fuel
• Intake air leak
• Misadjusted idle speed
• Misadjusted pilot screw
• Restricted fuel tank breather tube
• Clogged air cleaner
• Clogged slow circuit
• Starting enrichment valve open
• Faulty ignition system (section 17)
Afterburn when engine braking is used
• Lean mixture in slow circuit
• Faulty air cut-off valve
• Faulty pulse secondary air injection (PAIR) system
(SW, AR, Gil type only)
-Faulty PAIR control valve
- Faulty PAIR check valve
-Clogged hose ofthe PAIR system
• Faulty ignition system (section 17)
Backfiring or misfiring during acceleration
• Lean mixture
• Faulty ignition system (section 17)
Poor performance (driveability) and poor fuel economy
• Clogged fuel system
• Faulty ignition system (section 17)
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