Thanks guys for all the suggestions. I went ahead and bought a $99.00 Homelite "bandit" chainsaw at Home Depot. It looks like this will be the easies engine to convert since the stock carb is of the right size. I've also read that it is about as powerful as the Zenoah G38.

I'm going to build the Ultra Spad Stick to train with before taking up the Cub. This will be my first Giant Scale plane, so I want to fly for a while with an expendable giant scale first.

-- Acer
http://speedwing.net