I have a JP X12, when I took the engine apart I noticed that the bore thru the crank is the same size all the way thru it except for the end right where the counter weight is. It looks to be something in the casting of the crankshaft. The hole that the fuel comes thru gets smaller by about 1mm. Does this sound normal? If not can I smooth it out with a dremel? Anyone have any thoughts on this one?