what would cause By tvnacman (Read 390 times)

[tvnacman]

what would cause fuel to leak from the air filter when wot at or near max speed ?

John

[justbuggin2]

the only thing I can think of is restriction of the exhaust or to carb not flowing enough cfms

[tvnacman]

it is happening with back firing on the intake . Performance cdi I'm guessing with fixed advanced timing . I suggested testing with stock cdi . no change .

I imagine the fuel is sucked via vacuum , so how could it be pouring out of the air filter .

John

[alleyoop]

If that much fuel is coming out of the air filter then the carb is flooding. And naturally as vacuum is being applied and the float is not shutting off the fuel it will overflow out into the venturi and into the intake, which will cause backfires.

So I would take the carb off and adjust and check the float and check to make sure when level it does shut off the fuel from coming in.
You do that by putting a hose on the fuel inlet and hold the carb sideways like in the picture , then blow on the hose and gently push the float and see if it stops the air your blowing in.
Alleyoop

[tvnacman]

Thanks Alley , I got a phone call yesterday about this and did not know for sure . The part that puzzled me was at idle it did not leak .

John

[tvnacman]

Thanks Alley , I got a phone call yesterday about this and did not know for sure . The part that puzzled me was at idle it did not leak . I thought that it would leak all the time the bowl is over full .

John