Petcock Re-work

[JW-GS750E]

My 81 GS750E has a bad petcock. The internal spacer failed. Are there any issues, besides not being able to shut off the fuel at the petcock, with converting it to a manual mode until I can replace or repair it?

Thanks,
JW-GS750E

[habsdoc]

Forgetting

Yes, forgetting to turn it off every time, may allow gas into crankcase if your floats don't work properly. Other wise you should be OK.

[gs750caferacer]

Yes, forgetting to turn it off every time, may allow gas into crankcase if your floats don't work properly. Other wise you should be OK.

sorry thread hyjack... I just went to look at the oil in my bike and it was full of fuel?? could this be a bad petcock?

[tkent02]

Yes, only a bad petcock can do that, or leaving it in the PRIme position.

[gs750caferacer]

cheers thanks i was worried i was going to have to do a carb rebuild! I will tak e off the petcock and check it out. thanks

[tkent02]

You need a carb cleaning too.
They all do.

[gs750caferacer]

Yeah its in the plans but this is salvaged bike from the scrap heap.. glad it is a simple thing to start with as i have a few spare petcocks! I dont have a spare carb rebuild kit! just to make sure though the carb floats sticking wont cause the case to fill up? I havent really got the bike to start yet and i dont want to run it with gas in the case. im hoping that i can use my other tank on it and run it. Then i can begin the process of tuning it up!

[koolaid_kid]

You do not need and should not use a carb rebuild kit. They use poor quality components. What you need is an oring kit from cycleorings.com.
When you get to it, of course.

[gs750caferacer]

You do not need and should not use a carb rebuild kit. They use poor quality components. What you need is an oring kit from cycleorings.com.
When you get to it, of course.

So just rebuil with what i have aye?? CAnt i just get o-rings to match? I just read through the carb rebuild and it looks like a piece of cake! I just need to find some Carb dip???? that works or maybe an alternate??

[tkent02]

I dont have a spare carb rebuild kit! just to make sure though the carb floats sticking wont cause the case to fill up?

Not if the petcock is shutting off the fuel completely. The floats can leak all they want, there won't be any fuel to leak if there is none coming through the petcock.

[gs750caferacer]

True that makes sense. Everyone says buy new petcocks... Is there no way to rebuild them? What anout an in line ball valve or something to make double sure these accidents dont continue...

[tkent02]

Not sure about your 1981 750 but on most of them you can usually make an off position with a little effort.

[gs750caferacer]

Are meaning little effort like a vise grips on the hose.. Lol its a sinking ship with tge way it leaks...

[cowboyup3371]

People have tried to rebuild them but most end up failing again very quickly. There a lot of articles on here about their attempts but yours could end up differently. Do a search by clicking on Search, Advanced Search, Select Titles Only, and use petcock rebuild for your search terms.

[tkent02]

Are meaning little effort like a vise grips on the hose.. Lol its a sinking ship with tge way it leaks...

Not sure about your '81, but on the older GSes, you can do it like this:

Remove the steel ring with the two screws that keeps the lever in place. Inside this ring is a little tip that keeps the lever from going all the way around.
Grind away the steel tip, now the lever can move 360 degrees. Turn it to the new position with the lever straight up, there's your off position. You may have to shorten the lever so it won't hit the tank.

Replace the diaphragm with a piece of inner tube rubber so fuel can't leak down the vacuum line into the carburetor.