I built a fun fly 51 and put a thunder tiger pro 40 eingine I built the plane a lttle heavy because I epoxied my fuselage and for a prop I use a 12.25/3.75 with a 6 oz tank it balances perfectly the plane takes off within 10 ft and will do about any trick you want as a sports plane I can't hover but that's me when you're 60 you do one thing at a time I've got over 80 flights with it enjoy the plane it's well named