1150 Petcock Rebuild??

[Guest]

1985 GS1150ES. I think my petcock is leaking into the crankcase. I removed it and bought a rebuild kit. I removed the 4 screws and diaphram. Also the switch knob held on with 2 metal tabs. It looks like there is an O ring in the front and one in the back along with a diaphram. Is that all that needs to be disassembled and replaced? Also, do i need special washers to hold the petcock to tank? Thanks.

[dorkburger]

Petcock rebuild kits are said to have a high failure rate.

No personal experience though.

[journeyquest]

There is really nothing to them. 2 O rings and a diaphram. Ive used one on my GSXR with no problems. But it used a different kind of petcock. Not sure about this one?

[Plinius10]

Petcock rebuild kits are said to have a high failure rate.

I sadly can confirm this. just rebuid the petcock on my gs650 and now it doesn't flow fast enough at higher that idle revs...

[Steve]

1985 GS1150ES. I think my petcock is leaking into the crankcase. I removed it and bought a rebuild kit. I removed the 4 screws and diaphram. Also the switch knob held on with 2 metal tabs. It looks like there is an O ring in the front and one in the back along with a diaphram. Is that all that needs to be disassembled and replaced? Also, do i need special washers to hold the petcock to tank? Thanks.

Yes, that is about all you need to disassemble and replace. Yes, there are special washers. They have rubber inserts to seal the fuel.

And yes, I can agree with both sides of the argument presented so far. Overall, the success rate on a petcock rebuild seems to run about 10-15%.

I have no idea why what seems to be such a simple process has such a low rate, but I have attempted a rebuild on four petcocks myself, only one worked properly.

By the way, there are TWO ways the petcock can leak into the crankcase. One is down the vacuum hose, which leads straight to the intake tract on #2 cylinder. The other is if it does not close off properly AND one or more of the float valves in the carbs also leaks. Yes, that requires TWO "failures", but it's not unheard of.

.

[David450]

Hi I just serviced the petcock on my GS450 as it wasn't shutting off the gas. when I opened it up, the spring behind the diaphragm was missing. I installed a spare spring and it now works fine. If the float bowls are empty you need to suck on the vacuum hose to start the gas flowing til the bowls fill up for the first time, after that the carb vacuum does the job.
I have no Idea if the same works for the 1150 but noticed you didn't mention any spring in your list of parts

[hugo151]

Dont know this model but if it has a prime screw, there may be an o ring on it which didnt come with the kit for my gsx250. I had to measure & buy a viton one seperately which worked. If the prime setting fails it will fill the crankcases.

[Nessism]

One of the big challenges with rebuilding petcocks is that Suzuki doesn't sell parts for them. That means you need to use junky aftermarket parts like those from K&L or worse, and I've never seen a rebuild kit that had the proper parts inside.

FWIW, I rebuilt the petcock on my KZ750 and it turned out beautifully. Kawasaki sells the parts though.

[journeyquest]

I finished rebuilding it. The front lever is held on with tabs and there is a small spring and o ring inside. The back has the vacuum diaphram, o ring, spring and gasket. I emptied the crankcase and had a half qrt of gas in the oil. Afraid to run the bike until i know whats up. If the prime is left on, will that flood the crankcase with fuel? Thanks.

[tom203]

" If the prime is left on, will that flood the crankcase with fuel? Thanks."
most likely.... Just get new petcock and use old one as windchime. Why worry?

[Dave8338]

I'm anoher that uses my rebuilt petcock as a paperweight.

Junk kits and the replacments (on both bikes) have worked flawless for several years.