Originally Posted by
justin4
I have gas going back into the air box
Be more specific. Do you have a dribble of gas rolling out of the carb throat while sitting there or is it pushing air and fuel back out of the carb throat while you pull it over? Typically, a stuck float of other carb fuel level problem will send fuel out the overflow tube. Air/Fuel coming back out of the carb while cranking is a problem in your valvetrain. Stuck valve, carbon deposits in the seat, or mis-timed cam / crank relationship are all possible causes.
Is it possible the top end was apart in the past, either by you or the previous owner? If yes, then it is possible the cam timing isn't correct.
- Frank
1984 200ES Big Red
1985 350X (x2)
1986 350X
1986 250SX
1984 Auto-X
1984 ATC70
1985 ATC70