Startup/backfire/fuel leak problem!

[fil726]

I have a 1981 gs850l that has problems starting. It has a rebuilt petcock, carburetors, new intake boots, new spark plugs and battery. It used to fire up and die but it would eventually start up and run but there would be very intense backfires during idle. After changing the intake boots and sparks plugs it would not start up at all. I noticed some fuel in the airbox and I was wondering if anyone could help me diagnose these problems.

[Nessism]

Float is sticking for one thing. That's why there is fuel in the airbox.

[Big T]

When you say you rebuilt the carbs, did you follow the tutorial?

Because fuel overflow is typically caused by bad O rings and backfiring at idle is dirty pilot jets

[tom203]

Ditch the rebuilt petcock ....just get a new one to rule out its potential leak issues. Make sure you understand its 3 positions.

[fastbysuzuki]

Rebuilt petcock that could be a problem there are many post on here about that it seems there are far more reports of failure than reports than success. As all ready stated you have a stuck float possible dirt in pilots, air leaks in system causing weak mixture.
when you say rebuilt the carbs did you use the Oem jets or buy a kit?
did you replace the orings between the cylinder head and the carb rubbers?
Basically you need to follow the carb tutorial to ensure every thing is clean.

[Guest]

Fuel in the air box and it's back firing!? Cease all actions until you get that leak fixed. One good back fire into the air box and bye bye bike.