My 120 AX Special is behaving better, but this is certainly a different engine. Today, I went to the field with a 16x10 prop and no cowl. Engine started immediately, checked the needle setting, seemed rich enough, rpm was 8250. Engine stopped after 7 min of flight. This has been a recurring issue. After cooling and refueling, started the engine and richened needle to 8040 rpm. Flew 2 flights at this setting and was rewarded with 2 landings under power. That's the good news. The bad news is that at that power setting, the engine is not much better than a well worn stock 120. This is a rich power setting. The unburned fuel trail was very prominent. I assume the thinner head gasket is a major contributor to the overheating problems of this engine. Also seems to me, OS should treat this as a different engine and publish an addendum to their manual. The engine has 28 flights and a lot of ground run time... about 2 gal fuel, maybe more. Unless it gets significantly better with more running, I don't suppose I'll get more performance until fall or maybe winter. I might be underestimating the mount of break in required and the effect of operating in 100 degree temps, but so far it is falling way short on my expectations.

John