Leaking petcock

[Guest]

I have bought a rebuild kit for the original petcock and it still leaked, and now a ?new? Chinese petcock that leaks. How do I stop them from leaking. I have a 78 gs 1000. I don?t want to spend 200.for a Pringle.
ideas thanks

 

[Nessism]

The 750 petcock fits and is less than $100. The angle of the ports is different but at least some members here report success using it on their 1000's.

 

[steve murdoch]

Chuck has been using the '77 GS750 petcock.
https://www.thegsresources.com/_for...0-Tank-Petcock-ID&highlight=gs750+and+petcock

 

[cowboyup3371]

Where is it leaking from? If from the mounting holes, did you reuse the washers that were on your old screws or get new ones? If you didn't use any at all you'll need to get them as they are specially designed to seal against the tank

 

[Boriqua]

Where is it leaking from? If from the mounting holes, did you reuse the washers that were on your old screws or get new ones? If you didn't use any at all you'll need to get them as they are specially designed to seal against the tank

Yes that is what I was going to suggest as well. Did you install sealing washers. The ones you remove, if they have been there a good amount of time, are not happy about coming out and didnt in my instance ever seal proper again. That is your likely culprit.

I used some I bought at one of the big box stores and while not as elegant as the factory washers they worked. I can check the shed to see if I have others and send you a couple if you would like.

 

[superawesome]

I agree, would be best to know where it is leaking. Vacuum pipe, fuel pipe, mounting holes,...

Mine (same model and year) was leaking from the fuel pipe and I fixed it with a Tourmax rebuild kit and its been working since then. Hope it lasts.
Culprit was the 5-hole gasket that was shrunk in 40 years of usage. I stretched the spring slightly and made sure all the little holes are aligned.

 

[habsdoc]

They are called dowty washers are they not???

 

[chuck hahn]

Starting with post 133 here you can see how I used the elbow from my bad 1000 petcock and added it to the new 750 petcock so the feed was the same as the 1000.

https://www.thegsresources.com/_for...e-78-1000C-project/page4&highlight=blue+1000C

 

[Guest]

On my 78 Gs1000 I was having random issues with carb jetting. When the fuel tap started leaking, I replaced it with the Pringle parts, end of carb issues. For me, it was money well spent!

 

[aclaytonb]

Tried using a K&L on mine - garbage. Ended up with an OEM replacement. Costs about $100 but fixed the issue.

 

[Admiral Beez]

I just got my 1982 GS650G back from my local mechanic. Sent in the bike due to a leaky petcock, and they installed a petcock rebuild kit. But it still leaks. When the motor is running there is no leak, the petcock is dry, but when the bike cools down, there is fuel sweating behind the petcock handle. The mechanic says my petcock must be worn out, so I need to replace the whole thing.

Thoughts? Do these things really wear out beyond their gaskets failing? What replacement should I buy?

I never thought I’d miss the old fuel switch on my 1969 Triumph, where off was OFF!

 

[bwringer]

The petcock rebuild kits are pointless garbage, so that's not a surprise.

The petcock hard parts don't really wear out unless they corrode internally, but you simply can't get decent quality replacement rubber bits. So your best option is an OEM replacement.

There are some imitations out there, but the success rate with these is also mixed.


No petcock lasts forever, not even the one in your olde Triumph. I've never figured out why so many people here expect 40 year old petcocks to function flawlessly. There's nothing at all wrong with the design, and the fact that they're automatic is a huge plus -- it's saved many riders and engines.

I would understand the frustration if it were 1985 and your 1982 bike's petcock failed. But here in 2018, I don't really understand why it's so vexing or surprising that rubber bits failed after 36 years.


Pingel (Pringle sells crappy imitation potato chips, not petcocks) petcocks don't last forever, either, plus you've added expense and another component with a very high rate of failure, a squishy wet mass of goo known as your brain.

The floats, needles, and needle seats in GS carbs are not designed to nor are they capable of holding back a tank of gas while the bike is not running. Perfect, new components can and will leak tiny amounts over time, so it's VERY important that the petcock gets shut off when the engine isn't running, each and every time

The vacuum petcock is a great solution -- it's dead simple and reliable for at least two decades.

 

[tom203]

"The vacuum petcock is a great solution -- it's dead simple and reliable for at least two decades."

I agree...i bought one from this guy 7 years ago and it's still working correctly. Whatever you do, note that you need two special rubber bonded washers under the petcock mounting bolts or it will still leak!

http://www.georgefixs.com/brand-new...s550-gs650-gs750-gs850-gs1000-gs1100-petcock/


​

 

[Big T]

From you description, you need a new mechanic.
Petcocks don't wear out, the rubber bits go bad, or the vacuum diaphragm goes bad.

You probably spent the better part of the cost of a new petcock having someone badly rebuild yours
Time for a new one.

 

[Admiral Beez]

Perfect, new components can and will leak tiny amounts over time, so it's VERY important that the petcock gets shut off when the engine isn't running, each and every time.

My petcock has no shut off.

 

[tom203]

My petcock has no shut off.

Yes, it does or at least it did when it was working correctly
the vacuum petcock automatically shuts off when there is no engine vacuum - it's like magic!

 

[Admiral Beez]

From you description, you need a new mechanic.
Petcocks don't wear out, the rubber bits go bad, or the vacuum diaphragm goes bad.

You probably spent the better part of the cost of a new petcock having someone badly rebuild yours
Time for a new one.

You might be right. As best I can tell, the fuel is leaking from above the petcock, where it matches with the tank underside. I?ll be asking the mech who did the original work to recheck everything on Tuesday before install the NOS replacement petcock.

 

[bwringer]

You might be right. As best I can tell, the fuel is leaking from above the petcock, where it matches with the tank underside. I’ll be asking the mech who did the original work to recheck everything on Tuesday before install the NOS replacement petcock.

it sounds like the surface was dirty or messed up somehow, the o-ring wasn't correct or was damaged, and/or the sealing washers weren't replaced on the mounting bolts.

 

[Admiral Beez]

it sounds like the surface was dirty or messed up somehow, the o-ring wasn't correct or was damaged, and/or the sealing washers weren't replaced on the mounting bolts.

The NOS petcock is now installed and totally dry. Total cost new petcock installed $160. I have the old petcock and may take it apart for my own learning.

This winter I'll be taking off the tank entirely as I'm shipping out the sending unit for a rebuild.