Hi Suitcase, What was the problem that you had with the Y.S.? My winter project this winter is putting a Y.S. 120 in a Cermark 120 Pitts S2B. I got the engine NIB about 4 years old. I hope I dont run into your problems with mine. Was it the top end or the low end that you had trouble with? Looking forward to how yours turns out. wayne M.