From reading this thread, it seems to me that some of the misconception leftover from running glow engines is seeping in here. What you should want is the best performance from your engine running at the lowest possible RPMs pulling and braking like you need it to (propped properly).

RPM's don't matter worth a hill of beans so long as they are high enough for the engine to be running optimally (full advance). Let's be careful (talking to myself here too because I'm guilty too sometimes even though I know better) about thinking that we want our gas engines turning > 10k RPMs just because our glow engines do. RPMs don't equate to power directly. I guess that's what I'm really trying to say.