I have a BalsaUSA Eindecker 80" and am using a bone stock Weedeater(brand) featherlite leafblower 25cc. Stock muffler, carb, etc etc. The only thing I had to do to this was trim off the plastic, put on a prop spacer and fly it. It flies my Eindecker with authority, very scale but enough power to pull myself out. Here are a couple of pictures from a Warbirds event a couple of weeks ago. Had a great time, and had many compliments on the planes flight. You dont have to spend alot of money on these planes or engines. Mine cost me 37.50 (poulan factory store) and an easy to make prop spacer (just a spacer, dont need threading etc) I havent ground down the flywheel or anything. I love those cheap little motors. By the way, I had the cowl mounted crooked, forgot to check it when I put it back together, didnt notice until I saw that picture of it in flight.