I recently bought a Scorpa trials bike. It's a great bike but it was made in 2001, back before most gas had ethanol added to it. The tank was made of some sort of plastic or fiberglass that was dissolved by the ethanol and would gum up the carburetor. I was warned by the PO about this, and was told that if I ran regular gas I would need to drain the tank every time I used it. Annoying, but tolerable. After riding it a while, I discovered that the problem was worse than that- the carb would gum up before I could even finish a tank of gas. My options were: Buy race gas. At $65 for 5 gallons, not going to happen. Buy non-ethanol gas. I don't want to drive around to marinas to find gas, and the last place I went to that sold non-eth was 150 miles away and wanted an extra $1 per gallon. No thanks. Fix the tank. This is what I did. After a bit of on-line research, I ordered this kit from Caswell Plating. http://www.caswellplating.com/aids/epoxygas.htm It was about $50 with shipping. A bit spendy for a tub of glue, but it's about the difference in price between 5 gallons of race gas and regular gas, or the cost of two trips to a marina. In other words, it's a bargain. I had no proof that the epoxy would stick to the plastic of the tank but I figured that since paint stuck to the outside it would work. Here's the start: I also used electrical tape and plastic food wrap. I did not use the scale. I would not recommend using the foam brushes- use a paint stirrer instead. The instructions are good. Read them. Repeatedly. First get the old gas out using acetone, I used the whole pint. It's a really good idea to wear gloves. Latex is impervious to acetone, not all rubber gloves are. Then wash the tank out with detergent and hot water and let it dry. Next wrap the tank in plastic and electrical tape to keep the epoxy off the outside. The idea is that you're going to fill the tank with epoxy, seal up the openings, rotate the tank to get the epoxy on all the surfaces, then open the top and drain out the excess. After the epoxy starts to cure it'll get rubbery. Uncover the petcock hole and cut the excess epoxy away with a knife so that the petcock will fit in. If you fold some of the tape back on itself to make a tab, it's easier to remove. I don't have a picture of how I covered the top of the tank, but it's pretty easy. Just use a rubber band and some plastic. I didn't have a rubber band, so I cut the wrist of one of the latex gloves. Mix the epoxy. If you're doing several tanks at once or one big one, just dump it all in. I mixed half of each container. If you do mix half, it's important to get the ratio correct, or the epoxy won't cure properly. Unfortunately, I have no idea how close the ratio has to be. I was a bit busy to take pictures of the next part. After mixing the epoxy, pour it in the tank, cover the top, and shake it around, rotating the tank in every direction you can for a few minutes. Then take the cover off the filler cap and set the tank so the epoxy will drain out. Hot tip: figure out how you're going to set the tank to drain before you start messing around with the epoxy, not after. After about an hour, remove the tape that's over the petcock hole and trim up the excess epoxy. Let the epoxy cure for a few days. After it's done, clean up the filler neck. This is how it looked before cleaning it up. Finally, assemble and ride! I did this about a month ago, and it's worked really well. I have used regular E10 gas, never drained the tank, and have had no carb troubles at all.