Fixes for a leaky gas cap.


XS400 Member
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Ontario, Canada
I have a 1983 Yamaha XS400 SECA.

I don't ever overfill the tank. But I noticed that when leaning the bike on tighter turns gas would dribble through the tank gas cap and run down the side of my tank.

Now, I wasn't surprised by this. It's a 40 year old bike so I can only assume that some of its components are in need of replacement. I replaced the O-Ring in the gas cap and also carved another spacing ring out of cork to replace the chewed up remains of the original spacer inside the cap.

(I know that "spacer" probably isn't the right term, I'm a layman when it comes to this stuff).

I had hoped that this would fix my leaking issues. Unfortunately my hopes were dashed when the problem persisted.

Has anyone determined a way to stop the gas from dribbling out? Or is this something I'll have to live with?
The bad news on the gas cap is there doesn't appear to be replaceable parts listed anywhere like for the SOHC bikes. But the good news is that a lot of bikes used the very same cap you have, including the TW200 which is still around. So new caps are readily available.

The Yamaha part number for a replacement is 11H-24602-10-00. If you use that as a search term, you can also find non-Yamaha replacements for less money (but you might get what you pay for). The issue with any replacement cap is that your keys won't fit. If it were me, I would probably get a new cap and then disassemble the old and new and either swap the old lock tumbler into the new cap or use the new cap parts to rebuild the old cap.