I have the same plane and mine is powered with the 25cc Homelite with the big bore carb from www.carrprecision.com. It fly's great!!! This plane/arf is a really nice kit, nice flyer and good looker. I wouldn't hesitate a second to buy another if I ever auger this one in. I had the same problem with the flywheel being to close to the cowl. What I did was use white foam and extended the fuselage about an inch and thus moved the cowl mounting blocks out an inch which gave the clearance I needed. I covered the foam with yellow ultracoat and painted the cowl to match. It's so fun to bring this plane in for a perfect main wheels only landing. Have fun.