Bo, you are correct, the 120 is not the answer. The plane was originally set up with the O.S. 55AX and it looks as if that is going to be the largest engine that will fit into the plane without drastically modifying the nose area, but I think the plane will be somewhat underpowered at the 8-8.5 weight range.

The 60 size engines are all wider at the mounting flanges and will require substantial removal of wood to accommodate the engine mount, this also rules out the .91 Jamie referenced in his response.

I could probably get something like a Jett 50 or other hi-power 2 stroke to fit but will probably go with the 55AX due to cost considerations,

Thank you guys for your response,

Larry