I have a Giant Aeromaster that I have been flying for years with a "Quadra," 42. It fly's OK, (no reserve power) and I would definitely like to have more power. Mine was built from a "Ki,t" and is pretty heavy. About 21 lb. If you have one of the new ARF'S, I'm sure it's much lighter. I think an engine in the caliber of 50cc would serve you well. Maybe even a Zenoah, G62. Good luck with your Aeromaster.........You'll love it. Bob