Tom, it is powered by a PAW .40 Diesel mounted inverted. I had to dis-assemble the engine to get it in there, then re-assemble it in place. The prop is a 10x7 three blade that it turns at 9,000 rpm. I used to run a 12x6 three blade that it turned at 8,300 but it flew slugginsh with the tail kinda hangin low. Now it jumps into the air and flies with some spirit.