I bought one of these and installed it in my Magic Extra (3D plane) which was previously powered by a Norvel 40. The engine is not yet completely broke in. I'm using an OS F plug, Power Master 15% and an APC 12/6 prop. Up front I should say the engine is a very nice runner with performance as advertised and good throttle response plus good running reliability. Idle is reliable down to 2200 rpm and peak adjusted for flight is 9500 rpm. It has poor compression when turned over by hand and will not hand start but lights immediately when touched by a starter. But as I said it's not completely broke in. It has about 20 flights.

However I did have initial problems. The engine would quit on easy inside or outside loops and violent maneuvers. The tank was a bubbless so I switched to a standard. No help. I then began to realize that the engine was reaching max rpm well before full throttle (not really unusual I realize). However I noticed when the throttle was full open the engine ran slightly rough even though it maintained rpm. This occurred with lean or rich settings. I first verified that the throttle barrel was not going past full open and it wasn't. So I limited the throttle travel to just slightly more than that which provided max rpm. This is about 1 to 1.5 mm of throttle barrel.

This completely fixed the problem. The engine no longer even hesitates in any kind of maneuver or 3D exercises.

Any comments? Can you think of anything I might be doing or have wrong?

Denis Lyon