1976 XS500 Leaky Petcocks

[corlon]

i have a 1976 xs500 with 2 leaky petcocks. i just completely rebuilt both petcocks with new parts and they both still leak. they leak from the main body gasket, drain screw and from the front of the on/off/res valve body. any suggestions? can i use a gasket sealer?

[ramblerdrver]

Main body gasket...the "paper" gasket on the backside? Make sure all old gasket has been removed and that the backing plate hasn't gotten bent and that the screws aren't bottoming out (they have small lock washers, that, if missing, may allow screws to bottom out). Or do you mean the o-ring between the valve and tank. If that, be sure the o-ring has stayed in it's grrove AND that the attaching screws have fiber washers to seal them off to the valve body.

Drain screw...there's a fiber washer there to seal it off to the valve boddy.

Front off/on/res lever...it's kind of easy to not get this seated fully. Also, I think there is a front & back side to the rubber valve washer. The side that goes to the lever has a ridge around each hole, which acts as the sealing point.

Gasket sealer...probably not a good idea, as it would need to be gasolene proof, not mearly gasolene resistant...and that might be hard to find.

[Speedshop]

My 650 ones did this, in answer to your question no you can't use a gasket sealer. The rubber washers under the taps will have chunks missing so will need replacing. The remaining seals will want looking at to why they should b leaking, but you shouldn't need goop to keep the fuel leaking out.

[HoughMade]

You said "any suggestions"- and when it comes to old vacuum petcocks, I only have one suggestions: ditch them.

I;ve heard too many stories about the rebuilt petcocks leaking...or starting to leak again in short order. If you can get them to work right, they sure are convenient, but they're not for me.