Ditto the last response. I have a Patty Extra and I put a ZDZ40 in it. The best choice I ever made. The engine with a NX 20x8 prop pulls the plane around with a lot of authority. Plenty of speed and vertical performance. The gas is cheap compared to the amount of glow fuel a big 4 or 2 stroke would use. An added benefit is practically no clean up on a gasser. Go for the gas you won't regret it.