Gas cap seeping.....any fix?

I finally began riding my 82 650 after extensive refurbishing. I filled the tank today (not too high, but pretty full). It is leaking a little bit of gas as I ride. Barely enough to create a small run down the side. I am not really concerned about safety, but I don't want it to leak at all. Can the cap gasket be replaced? Is it available from Yamamama? If not, then what do I do :?:

 

The gasket is replaceable but they reproduce them every few years and your hosed if you need one in the time between. I had to wait 3 years for my replacement. There is only one other method I can think of an that would involve using some small rubber coaming glued into place around the original disk. Best I can think of right now. Anyone else got a bright idea?

 

My good man I had the same problem last summer and ordered a replacement gas cap gasket at http://yamaha-factoryparts.com/ for $12.95. Works like a charm and they are made by Yamaha to boot. Hope this helps.

 

if you run to menards with your old rubber gasket, or really any farm implement store you can get a rubber washer about the same size but... you have to cut out the inside to fit....worked for me, cost about a buck USD, good luck!

 

Thanks all,
After taking the cap apart, it is obvious why it seeps. The rubber is old and cracking. This is actually a pretty complex part with a metal center and a spring wrapped top that seals to the cap. Now I see why it is more expensive than just a rubber washer. CTsommers, I appreciate the lead, but for shipping one item it is not cost effective. $12.95 for the part, plus $10 for shipping. My local stealer is about $18, so I will order it locally. Hey, at least you can still get parts!!

 

If you shop around, you might find free shipping from some places. I know BikeBandit charges a flat rate of $7 no matter how much I've ordered (from $20-$500 so far).