I'm flying mine for a Saito FG14 (gas, 14cc, 4 stroke, equivalent to a .82 4 stroke or about a .60 2 stroke). Performance isn't out of this world, but it is solid and will do everything the plane is designed for. The Saito swings a big prop and the acceleration from idle to WOT is good. I don't think the plane can go quick (too much drag), so going above the recommended motor size probably won't add too much to this plane (apart from the vertical performance).