Of the 50 class engines I own, all run well but are quite different from each other. I wouldn't exchange them between the airplanes they are currently in. I've preached a long time the importance of matching an engine to its application rather than just picking an engine because its the best performer in its class or because its carb is mounted where some people think it shouldn't be. Some people think a piston port, side carb induction engine can't perform up there with a rear intake engine .... they are missing the enjoyment many engines could offer them. This is probably going where it shouldn't so I'll quit now.