RE: Running without prop
I smacked one inverted one time. The plane popped back up. The prop went from a 11x6 to a 2x6. The engine turned about 50,000 for about 1/10 of a second. I could not tell you if it died from overheat or no flywheel or what. I really thought it had thrown a rod or something. Once I fixed the plane it ran fine.
David