drippy (pet)cock....

I'm an avid bike mechanic but new to vacuum petcocks. Mine pisses fuel everywhere even in the on position, not as fast as it does in prime, but still a substantial amount. Don't these usually present failure by not letting any fuel flow? Must I rebuild or will a cleaning solve this? Kind of worried that ill end up with a crank case full of gas one night...they should have put an "off" position on these things. I've already gotten a lot if great info from this forum, great community we have here. Thanks in advance for the help.

 

they are very simple to rebuild and the kit is cheap to purchase. its simply a diaphragm in there, a couple seals and a filter neck thing.

take it off, take off the 2 screws and look around to see whats at fault. it should be pretty obvious

 

Re: drippy (pet)c**k....

Petcock rebuild: http://xjbikes.com/Forums/viewtopic/t=25058.html

Read that and you'll know exactly what's in there before opening it up.

If you end up with a crankcase full of gas, not only did the petcock have a problem but one or more of your float valves failed their task as well.

 

Re: drippy (pet)c**k....

If my floats weren't working wouldn't gas also be pouring out of my overflows?

 

Re: drippy (pet)c**k....

Not necessarily. A leaky petcock alone won't fill your crankcase with fuel; leaky floats AND a petcock problem can. Fuel won't necessarily run out the overflows, it can simply drain into the engine. It's a relatively common occurance. If the float valves are working correctly, they will shut fuel flow off at the carbs regardless of what happens at the petcock.

 

Re: drippy (pet)c**k....

mine was leaking from the outlet tube on the petcock. the tube wasn't secure into the molding. i used a jbweld coating around the connection to keep it in place and stop leaking.

other then the leaking outlet tube. my switch worked like it was supposed too.

if yours turns out to be the same problem. don't buy the gas sealer stuff that autozone sells. that stuff is kinda like superglue. after 2 days it dries out and turns to sugar. now you're back with a leak and a sugary glue mess to clean up.

 

Re: drippy (pet)c**k....

Outright leakage due to a failure such as that and a valve that is failing to shut off are two different things. I was referring to a valve that doesn't shut fuel off properly, either via the selector lever and/or the vacuum valve.