Petcock problem?

[fifer]

Hi all,
I am looking for a bit of help with what I think may bea petcock problem. I am working on a bike that has been sitting for many years and I have recently finished putting the carbs back together after a rebuild and I now have noticed that no matter what position the petcock is in there is no fuel coming from the tank. I just got a petcock repair kit and I was wondering if anyone could help me through this or does anyone think it is something else?

Thanks,

Mike

[J_C]

If the petcock is on prime then the gas should flow freely (someone correct me here, Somone said you may need a bit of vaccum to start it?)

If its on run then the fuel shouldnt flow unless you create a vacuum on the vacuum line. (Put the vacuum line in your mouth and put the fuel line in a bucket. If you suck on it like a straw then fuel should pour into the bucket.)

That's all I know about petcocks. My prime didnt work so I just bought a new one for $45 on ebay. Good luck!

[frosty5011]

Hi all,
I am looking for a bit of help with what I think may bea petcock problem. I am working on a bike that has been sitting for many years and I have recently finished putting the carbs back together after a rebuild and I now have noticed that no matter what position the petcock is in there is no fuel coming from the tank. I just got a petcock repair kit and I was wondering if anyone could help me through this or does anyone think it is something else?

Thanks,

Mike

Is it an '80 model bike, and the petcock has no handle? (just a screwdriver slot?)

[fifer]

Is it an '80 model bike, and the petcock has no handle? (just a screwdriver slot?)

Actually it is a 1982 GS650GLZ

[jscwerve]

Sorry to hi-jack, but thank you for the info on that 80 model, I just picked up an 80 750 and was going to go to the part store tomorrow for a petcock because I thought my handle was broken off. Thanks for saving me the $$$!!

[kalessin]

I had an '82 GS650GLZ... still miss it sometimes

The petcock should flow gas freely in the "pri" position, and should flow with vacuum in the "on" (or "run") and "res" positions.

If it's not flowing in the "pri" position, it may be gunked up and clogged, in which case you should remove and disassemble, clean the metal parts with carb cleaner, etc.

It's always better to drain the tank, but here's what I did: if the tank is mostly empty (probably is), then lay it on it's side on top of some rolled up rags (careful don't scratch the paint...) with the petcock on the high side and open up the petcock to replace the internals. Work gently.

The rebuild kit is really easy to install (I didn't remove the petcock from the tank, so I didn't replace the gasket there). Test after you put it in, I put the diaphragm in backwards by mistake the first time, and the petcock wouldn't shut off.

[chuckycheese]

Petcock

I'm a proud owner of a '80 GS750L. Those petcocks are awful and I fear that the problem you are experiencing will be the first of many. I wouldn't spend a nickel on it...I'd get a Pingel and be done with it for a long time. I think you will hear other similar comments....8-[

[Poot]

so, if you suck on the vacuum line gas should come out of the fuel line? or is it blowing in the vacuum line?

[J_C]

Sucking (Constant pressure). Make sure the fuel end is in a bucket or bottle and not your lap