I just picked up an ACE 4-60 (out of production) Biplane at a great price with 5 servos in really clean condition. This will be my first biplane and was told it is a real gentle flyer. I have an older OS61 4-stoke I was thinking about using on this. The owner had a 61 2-stroke that he took off and used on another airplane. My question is will the 61-4S be enough power for this machine or do I need a 90-4S? For a Bipe it's size, it's pretty light weight. DG