im working on a cylinder head off a utv, it belongs to a friend of mine otherwise i wouldnt touch one of the things , dont know much about them, and since it doesnt say "harley" on it im not much interested in learning lol, but besides a bent valve it has 2 bolts a little smaller than 1/4 inch broken off in the head, below the surface, im wanting to get them out as they hold the exhaust manifold on and it probably needs them, these things have obviously been broke off for awhile and im planing on trying to drill a pilot hole thru the bolts,and try a eze out first, im plenty bothered though first this engine is water cooled and i dont know where the passages are relative to where the bolt is in the head , then the bolts are so small im afraid a small eze out will just break off then i really have problems, also im leary of heating the aluminum with a torch to help the bolts come free, the brand is hisun, which is an odd ball over here although my son who is stationed in japan with the navy says the brand is everywhere over there, one of the most popular ones , any advise will be appreciated for this