Nonstoprc,
I just mounted my 50 to the plane and ran a tank at home on mid throttle then took it to the field and am now in the 3rd gallon of break-in gas. I agree with all who say the cooling is better. It got a bit warm on the first few runs and I was glad it got as much cooling as it could. I also agree that in the early time just sport/imac stuff is perfect for break-in. I really like this engine. !~)

Joe