I converted an 18cc Poulan Featherlite for a buddy of mine. It is on a balsa USA Eindecker with an 80" wing span and weighs 14 lbs. The Poulan is turning a 16 x 8 APC at 5800 RPM. with the stock exhaust. There were no modifications done to this engine other than the conversion. This engine is flying the plane in a very scale like mannner.