RE: Skyraider Mach 1 and FS52AR engine?
If you were getting 11k on the ground that will damage your engine. 4 strokes will get into a condition called valve float where the valves stay open past the peak of the camshaft and then slam closed. That's really rough on your springs first, so the rpm where valve float will happen goes down into the normal operating speed of the engine. Eventually your valve will break and usually will destroy your piston and score up your cylinder.