Leak at the petcock

[Riffraff123]

Hello, just when we thought we had everything done...bad gas smell in garage and looking closely, have leak at petcock. No leak from carbs, so float valves are working. I did a rebuild kit, that did not replace the spring or plunger o-ring. It did have a really big o-ring in the kit that wasn't anywhere on mine. Tightened clamps on lines. The valve seems very simple and the only thing that would make it leak externally is a crack which i can't see, or a bad seal. Functionally it works well, tested prime reserve and on, flows well with vacuum applied. 1997 750. Did search and found nada or incomplete threads on this. Almost all "leaky petcock" threads were for valves that won't shut off. Any common issues? Or something I missed?

[92xjunker]

Take it apart again and check for pinched o-rings or seal.

[shpielers]

Dried gas can leave behind a varnish that might prevent the orings from getting a good seal, might want to make sure the surfaces that the orings are contacting are clean.

[Riffraff123]

O ring on the plunger? Or in the knob assembly? Or both? This things making me nuts! Thanks for replies!

[RobertTravis]

http://katriders.com/wiki/index.php?title=Petcock

[Kreylyn]

I'd need to know where it's actually leaking to know what to tell you.

Krey

[Riffraff123]

I'd need to know where it's actually leaking to know what to tell you.

Krey

Hi, it's really hard to tell. Even looking close with a flashlight I can't see exactly. It drips off the lowest point on the back part that has the hose attachments. I'm just going to take it apart again.... clean everything up, again.... and be super OCD about putting it back together. Anyone know of a quick source for replacement part if it's cracked? Or if there is an alternate petcock to buy (kinda cheaply)? I am Harley guy and I replaced mine with a Pingel, but I only have one hose out to carb and not even close to same mount to tank.

[92xjunker]

That in the diaphragm assembly, there is a slot that will drip if it is worn or assembled incorrectly.

[Riffraff123]

Robert, thanks for the diagram....helpful. I did check the wiki and found good info, but nothing specifically on my type of leak. I will add it once I figure it out.

[dnelli]

Hello, just when we thought we had everything done...bad gas smell in garage and looking closely, have leak at petcock. No leak from carbs, so float valves are working. I did a rebuild kit, that did not replace the spring or plunger o-ring. It did have a really big o-ring in the kit that wasn't anywhere on mine. Tightened clamps on lines. The valve seems very simple and the only thing that would make it leak externally is a crack which i can't see, or a bad seal. Functionally it works well, tested prime reserve and on, flows well with vacuum applied. 1997 750. Did search and found nada or incomplete threads on this. Almost all "leaky petcock" threads were for valves that won't shut off. Any common issues? Or something I missed?

The large oring is for the fuel tap flange that bolts to the underside of the tank.