petcock leak

[rcalaga]

Just yesterday, gas started to leak from the washers of the 2 screws on the petcock that go onto the fuel tank. I went to hardware store and got a couple of neoprene washers but the leak doesn't want to stop. Has anyone had a problem like this ?? Where can find the new washers and the o-ring.
thanks...

[Lucky]

if you replaced the & it still leaks, then you need to carefully re-examine the petcock for cracks & serious corrosion.

if you didn't replace the o-ring, you can try some fuel proof sealer schmered on the old o-ring, or play match up at the hardware store.

i don't know if the keyster kit has those seals or not... (82 only)

--Lucky

[rcalaga]

Lucky, I was able to find an o-ring from the home depot that fit perfectly but the fuel seems be creeping thro' the screws. The petcock base looks in decent condition, no cracks.
I am going to see if I can find some washers from the motorcycle store tomorrow - they seem to be made of some cloth or some other material. I hope this fixes it, else I am not sure what else to do.

[Rupert]

I've had a similar problem before because I was trying to do preventative maintenance!

Get some rubber, cut it into 2 squares, fold over in half diagonally cut a small hole in the centre. This will make a 'square' type rubber washer, and now you can trim the outer edges if you want it to look round.

I did this as I had to replace the factory screws, I installed some stainless cap screws with washers, easy to install and remove.

:)

[rcalaga]

Rupert, What kind of rubber material did you use??
I got these neoprene washers from home depot, but they are thick and very soft and compress a lot when I tighten the screws. The fuel still seems to leak thro' the screw with the new washers.

[Rupert]

Just used some rubber that came with bicycle light clamps, about 1.5mm thick, left over stuff.
Perhaps try a gasket making place or two and they could give/sell cheap some wee offcuts of gasket rubber.

[rcalaga]

After several washers and some careful inspection, it looks like the leak is coming from between the petcock and the fuel tank. I tried putting a new o-ring but didn't help much. Should I try to get a new petcock ??

[Rupert]

To be more precise, do you mean that fuel is leaking between the o-ring mating surface of the petcock assembly and the gas tank?

If yes, is your replacement o-ring the proper rounded rectangle type or just a round one made to fit the shape?

Also, you could try cap screws instead of the philips head type screws so you can tighten down the assembly to the bike a bit firmer.

Not sure about trying a new petcock though..

[louthepou]

Sometimes, the surface of the tank where the petcock should sit isn't that flat and nice anymore, thus allowing a leak. Make sure it's clean and flat. Like Rupert says, the stock Yamaha gasket, new, is the one to use.

We'll get there!

Louis

[rcalaga]

Rupert, Yes the leak seems to be coming from surface between the tank and the petcock, and the new o-ring I have is just a round rubber 0-ring that fits almost perfectly into the groove. I figured this would do the trick but maybe as you say I have to probably get the real part.
Both surfaces look pretty flat to the eye. I will try a hex screw to tighten it bit more. thanks!