gas in the crankcase

[vette64772]

How do I determine if the gas in my crankcase is caused by a faulty petcock or a stuck needle valve? I took my 82 gk out for a run today and 1/2 mile out on the highway she started coughing and losing power and finally died. Pulled her over and there was ugly oily fuel spilling out from my airbox. Airfilter full of fuel/oil........making alot of white smoke as I managed to get her home. Drained oil and it was full of fuel............how do I trace down the cause of the issue? Thanks guys....just hit the 60's here in Missouri and would love to get out soon!

[piester]

well. if the needle seets were good you wouldnt have had gas in the crankcase right? its the last stop. and if you didnt leave your petcock on prime and it leaked in run or reserve then the petcock could be bad too

[TeamDar]

It is a faulty petcock or you left the petcock on prime. Even if the float needle is stuck it would only leak when the motor is running since the petcock is automatic and only flows fuel while running. If the motor is running it is unlikely that gas would fill up your crankcase. If the petcock is faulty then gas would flow all the time and would fill up the crankcase. Dar

[Billy Ricks]

You could have a hole in the petcock diaphram. Pull the vacuum line off and see if there's fuel in it. As has been already pointed out you may have left the petcock on prime and you have either bad float seats or the o-rings on the seats are bad allowing fuel to overflow.

[cdnoel]

Bad petcock.

The petcock can fail in two ways. It can fail open wich would over come even good needle valves. Another way it can fail is a hole in the diaphram. This will drain gas right into the vacume line and fill the motor directly. At any rate if you have an empty tank and full crank case it has to be the petcock. Check for crud in the shut off valve/O-ring and check for holes in the diaphram. If you'r not sure get a rebuild kit and you'll be all set. A good way to check the petcock for proper function after rebuild is to give the vacume line one pump with a brake vacume pump. When the gas flows let off the vacume and it should stop. let it rest for a while and check for leakage. Others don't like the vacume petcock but once rebuilt I think they are extreemly convienient.

[vette64772]

source for petcock?

Any good places to get a new petcock?

[Billy Ricks]

Any good places to get a new petcock?

Depends on if you want a vacuum type or aftermarket. Z1 Enterprises sells a vacuum type replacement and Pingel Enterprises sells a very nice petcock that doesn't need a vacuum line. Z1 is operated by a member here, Jeff Saunders, and comes highly recommended. Nice guy to deal with. Both sources have websites.

[vette64772]

thanks billy

[renobruce]

Depends on if you want a vacuum type or aftermarket. Z1 Enterprises sells a vacuum type replacement and Pingel Enterprises sells a very nice petcock that doesn't need a vacuum line. Z1 is operated by a member here, Jeff Saunders, and comes highly recommended. Nice guy to deal with. Both sources have websites.

Z-1 also sells an aftermarket Pingle type petcock that others have said works great at a much better price.

[Billy Ricks]

Z-1 also sells an aftermarket Pingle type petcock that others have said works great at a much better price.

Good info Bruce. I need to take a look at that. My GSXR has the lever broken off the petcock so I can't switch to reserve on the fly.