What should I use to clean my gold ring chain with without damiging it? My GYTR muflers welded seam on the side split in half should I send it to yamaha fix it or what? Is bakfiring and poping (is it the same thing) just a litle ajustment or is it timing? Can you port and polish a 4 stroke ? if so who will do it? what is the best performance part I can do to my 03 450?