Here's the dealio, I just bought a new tank off ebay for my yz400f, IMS dry break. Installed the screw cap conversion and everything. Put it on the bike, filled it up with gas, and it started spewing around the petcock pretty substantially. Apparently there's a special gasket that is supposed to come with IMS tanks... didn't recieve it in the bargain. I went all over town looking for somebody who might have something that would work, and didn't find anything. Liquid gasket seems out of the question, cuz gasoline eats that stuff up. Finally found a dealer in town that gave me (for free!) a piece of gasket material... I trimmed it down to fit the petcock and punched holes in it for the screws and filters, and installed it. Works like almost a dream. I'm still having a very slight leak, maybe a teaspoon every few days, and I'd like to make it freaking seal up permanently. My question is, where can I buy IMS specific gaskets, and would JB Weld work?