retired wrote on 04/17/10 at 16:05:40:I am wondering if with the Rapter petcock if I should block off the two Carb. vent tubes?
Never!
Now that we know a lot more than the original post...
I suspect the float as well, he had several problems, and never found out directly what caused the "gas blowing out the intake" problem. He did go thru his carb, found a broken part, got another, had same problem, adjusted his valves, found a loose wire, got it running, no longer to be seen till the next problem.
if your carb has a drain nipple we can attach a clear tube to, we can check the float height. stick a clear tube on the drain, hold it up along the carb, open drain valve, see how high the gas goes, petcock to prime, how high does it go? should come up to the bowl gasket. If it doesn't then you need to adjust the float height. if it does and keeps going, you need a new float valve.