Basically it was an air leak between the case halves. The gasket surface between the cases was way out of flat due to a previous re-build. Aslo, an ear was broken off by the stud. Some one had used a screw driver in the slot by the clutch and had broken the case. We welded the pieces back in, then stoned all the major gasket surfaces flat. Also put a new power valve in it.
Now if I could just get Jay to use the Rotax jetting! :loony: