Troubleshooting - Honda Magna VF750C Service Manual

Fuel S y stem

Troubleshooting

Engine Won't Start
Too m uch fuel getting to the engine
- Air cleaner clogged
- Flooded carbu retor
I ntake a i r leak
Fuel conta m i nated/deteriorated
No fuel to carbu retor
- Fuel stra i ner clogged
- Fuel tube clogged
- Fuel va lve stuck
- F loat level m i sadj usted
- Fuel ta n k breather tube clogged
Lean Mixture
Fuel jets clogged
•
Float va lve fa u lty
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Float level too low
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Fuel l i n e restricted
•
Carbu retor a i r vent tube clogged
•
I nta ke air leak
•
Th rottle va lve fa u lty
•
Vac u u m piston fa u lty
•
Cal ifornia Type On ly: Evaporative em ission carbu re­
•
tor a i r vent control va lve fa u lty
Rich Mixture
Sta rting en rich ment va lve i n ON position
•
Float valve fa u lty
•
F loat level too h i g h
•
Ai r jets clogged
•
Air clea ner conta m i n ated
•
Flooded carbu retor
•
Engine Stall, Hard To Start, Rough Idling
Fuel l i ne restricted
•
Ignition ma lfu nction
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Fuel m ixtu re too lean/rich
•
Fuel conta m i n ated/deteriorated
•
I ntake a i r leak
•
Idle speed m i sadjusted
•
Float level m i sadjusted
•
Fuel tan k breather tube clogged
•
Pi lot screw m i sadj usted
•
Slow c i rcuit or sta rting enrichment circuit clogged
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E m ission control system m a lfu nction (Cal ifornia Type
•
On ly)
- Evapo rative e m i ss io n carbu retor a i r vent control
valve fa u lty
- Evaporative emission p u rge control valve fa u lty
- Loose, d i sconnected or deterio rated hoses of the
em ission control system
5-2
Afterburn When Engine Braking is Used
Lea n m ixtu re i n slow circuit
•
Ai r cut-off va lve ma lfu nction
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E m ission control system m a lfu nction (Cal ifornia Type
•
O n ly)
- Pu lse secondary a i r su pply system fa u lty
- Loose, d isconnected or dete rio rated h oses of the
em ission contro l system
Backfiring Or Misfiring During Acceleration
Ignition system fa u lty
•
Fuel mixtu re too lean
•
Poor Performance (Driveability) And Poor Fuel Economy
Fuel system clogged
•
Ign ition ma lfu nction
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E m ission control system ma lfu ncti on (Cal ifornia Type
•
On ly)
- Loose, d isconnected or deterio rated h oses of the
e m ission control t!YStem
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