Leaking Petcock

I did a search on this and did not find an answer.....my '99 WR is leaking gas at the Petcock. I have an IMS tank so therefore I have the Petcock mounted on the header side so the valve is towards the engine. It was leaking pretty good when I started the bike ....luckily I didn't have to call the :D

I took the petcock apart and cleaned it up and put it back on....still leaking :) It's not leaking as bad as it was but leaking nonetheless. Will replacing the little O-ring solve my problem? :)

Do you have the special gasket that is required for the IMS tank? I'm just learning about this now, as I bought an IMS tank from somebody on EBay and now I can't mount it until I get the special gasket it requires. The brass inserts on the IMS tank stick out too far to use the OEM seal, so it requires an additional seal. Some people on here have had good luck filing down the inserts smooth. I took a fellow TT'ers advice and contacted IMS, they are sending me a gasket for nothing. I was really impressed with the service. If it takes too long to come, I'm going to try to make one out of some gasket stock or something.

I am going to presume that I have this gasket.....I've had this tank on my bike since new and have never had a problem. I should have mentioned in my original post the fact that I drained the tank last fall. I'm guessing the o-rings dried out with no gas.

You can rebuild the petcock with new seals from Yamaha. The mount gasket is also factory. I rebuilt mine and I use a IMS tank.



This may sound weird, but if it's leaking where the petcock sits against the tank you can use the gasket out of a garden hose to place between the tank and petcock. This has worked for me 2 times on 2 different bikes...

I'm sure you need another gasket. If you do a search on the YZ4xx forum, you'll find some info about this problem.

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