Petcock fix with JB Weld

nustar1 · #1 03-01-2010, 09:05 AM

Ok, I rebuilt the petcock with the RetroBikes But either the petcock body was damaged before or more than likely I broke it by tightening it to much. It leaks pretty bad around where it seals to the tank. The aluminum has some minor cracks in it and the tank doesn't seem flat and true. I was thining of using some JB weld to adhere it to the tank. Anybody try that yet?

I was thinking of removing the rubber O-ring and use the JB Weld Stick to roll out a string like you would with play-doh. Then place the string in the O-ring's grove.

Any opinoins on this idea?

The parts replaced with the Retro Bikes kit seem top notch. I had to drill out the cork holes a little because they were a little to small to push in right. And I used a socket which helped also. Not selling it but I don't want people to get the idea it's their fault. What would the correct torque specs be on replacing this thing anyway?

mk2davis · #2 03-01-2010, 01:45 PM

have you thought about making your own gasket out of thicker material, using the Retrobikes as a template. Seems like a better option than JBW.

Although I am a big fan.

Spokes · #3 03-01-2010, 02:21 PM

Check the condition of the cross spring before making any decisions. The cross spring, if weak or broken will cause the petcock to leak. The retro bikes kit works well, even though the little 3 hole gasket that is sandwiched between the adjuster needs attention.

It also helps if the mating surface between the tank and the "o" ring is flat.

Finally, cracks in the housing is not a good sign.

If all is good, try a slightly larger "o" ring before going to JB. Get an "o" ring made from Viton. Viton withstands exposure to gas real well.

nustar1 · #4 03-01-2010, 08:40 PM

I tried using some gasket in a tube that works with fuel. It didn't work the first time. The second. I don't think I let it dry enough. The x spring seems OK in that it's not broken and seems to maintain its shape. not sure what else to look for. A larger O ring might be a good idea but i'm sick of failure. as the tank may be warped or at least the petcock frame. I figured the larger and more fuel stable the gasket (jbweld) the better my chances. But I do appreciate other ideas. I'll think more about the larger o ring

Spokes · #5 03-01-2010, 09:03 PM

I have rebuilt these petcocks with success. I would love to see it up close. If you want, you can pm me and perhaps send it to me before doing the JB on it. I have a gasket specialty shop that can supply an "O" ring.

I would do the analysis just for shipping charges only, it's a hobby for me.

srq68 · #6 09-11-2010, 04:20 AM

Spokes,
would the JBW hold up to gas if it is used to plug a hole in the lower cup of the petcock?

Spokes · #7 09-11-2010, 06:20 AM

I am not too sure of the JB Weld holding up under the constant volume of fuel like at the bottom of the fuel bowl. Maybe it is OK for a temp fix, but I would replace the bowl for the long term.

Smithers · #8 09-11-2010, 04:55 PM

I have JB weld holding up on a plastic fuel tank on my Aprilia! It's been holding for a couple years but it's near the top not the bottom. I can't believe how well it's working. I would definitely love to try using it on a hold in a fuel bowl to test it even further. I seriously think as long as the hole isn't huge and you prep the area very well that it would hold.

You should seriously think of the safety aspect of doing such a repair though. I really don't want to hear about how someone would try something like this and have fuel run all over their engine and ignite into flames so please be careful. I don't think this would happen but there is always a chance.

As for the o-ring seal between tank and petcock it's hit and miss depending on how well the tank surface is. You can always have it brazed by someone and make the surface completely flat. I was going to do this if my seal didn't hold. Make sure you get that sucker super clean!

srq68 · #9 09-20-2010, 05:46 AM

I did some research on gas-resistant epoxy and found one called Red Epoxy, which is heat-cured and seems to be promising for gasoline-related problems with bikes.
I ordered one kit to assemble an aluminum petcock bung to an alu adapter plate for my tank. We'll see how it goes....

Martskin · #10 06-12-2012, 06:10 AM

Hey all,

I bought a rebuild kit for my petcock because I wanted to use the stock petcock but when I inspected the previous owners mod closer I realized the screws had been sealed over. Is this JB Weld? Now I'm wondering if I should just leave it since it works but it's not pretty. :/

Smithers · #11 06-12-2012, 07:13 AM

I don't think it would be worth the time and effort to fix that tank seeing how it's all gummed up like that. Looks like you would have to grind all of that away. You could try vise grips on those screws to break them free but that custom plate looks like it might be sealed on the tank surface with the same JB Weld looking stuff. That's too bad.

Puzzleparadise · #12 06-12-2012, 07:38 AM

Quote:

Originally Posted by Martskin

Hey all,

I bought a rebuild kit for my petcock because I wanted to use the stock petcock but when I inspected the previous owners mod closer I realized the screws had been sealed over. Is this JB Weld? Now I'm wondering if I should just leave it since it works but it's not pretty. :/

I had a similar scenario with my previous tank that had a workable aftermarket petcock but managed to locate another tank with an original petcock that I refurbished with a RetoBike kit and it works flawlessly now...they do come up on eBay now and again...I now have that tank (with the aftermarket petcock) in case anyone is interested in it, but probably not worth the shipping cost unless you're in Canada...I'd be happy to check on shipping costs in any event in case someone is in need...it's the least I can do for all the help I've received from the generous members on the forum..

Martskin · #13 06-12-2012, 08:22 AM

Thanks guys. It works the way it is so I suppose I should leave well enough alone. Although my mind keeps going back to it. I guess we'll just keep an eye out for a replacement tank without a petcock.

Larzfromarz · #14 06-14-2012, 01:19 PM

For the life of me I wish one of you Audi owners would break into your pile of cash and have a bunch of new billet petcocks made for everybody.Shesh...

Smithers · #15 06-14-2012, 10:06 PM

How about gold? Everyone hates the original ones for obvious reasons... then everyone hates the aftermarket ones because they don't look near as pretty as the originals.