Sarge: I have the Four Star 40 and have used three engines on it so far: the Evolution 40, worked out ok, lacked power, then switched to the OS46FX, ran just fine but I wanted a little more in the vertical, so I switched over to the OS50SX which flys just great. Keep in mind that prop selection will also make a difference in how it will perform with various engines.

I have an OS52 Surpass that I was going to put in that plane but at 1.1 bhp it just didn't seem to have th umph I was looking for. Besides, the throttle is on the other side and to the rear on the 4C which would have made for some fun with the servo re-locate or at least the relocate of the servo linkage to the carb.

DS.