Ok another question I have a horizontal inline 2 cylinder, 2-stroke engine that i purchased. it was originally on a snowmobile, it's a 488cc that produces approximately 55hp at the output shaft. I'm not sure on the torque of the engine but if I had to guess it would be above 30ft/lbs, the engine can turn upward of 5500 rpm's , my main questions are if anyone has any idea what size prop I should start with. It will be a longtail build and I'm going to shoot for an all aluminum frame since the motor itself only weighs 85 lbs without the frame.

my bet is you will end up with somthin like one of those thi motors. speed with no low end power. i woulnt mind using that type motor on a sd, with lots of gearing.