Quote Originally Posted by Yamaha3wheeler View Post
Most of the mess you see is the gasket in there and the rust left from the steel header. I haven't pulled it yet as I just got the exhaust header off last night. I think I can clean it up decent. If not, I'll take your advice and look for another head.
That's tough, but not impossible. Since your down tube is in the way I would pull the motor and get under some good light on a bench. As suggested, sand/file the bolts down smooth to get a clean, straight bolt face. Then get a really sharp punch, place dead Nutz center and create your pilot dimple. Creating this dimple also "shocks" the bolt (I usually do this twice). Then, start drilling with tiny bits and work your way up drilling at very low speeds with plenty of oil until there is about 1/16th or more metal from the outside of the bolt. Then, just spend the money now for a quality extractor set (check out the link onformula1 posted). Take your time with the extractor and it should come right out.