That is my point Creampuff, if both mags are off, grounded, the engine stops.
C'mon Eddie, stop evading the point of the question you're purporting to answer.
What type of engines fitted to what aircraft, precisely, stop rotating in flight when the mags are switched off or the fuel runs out? I'm yet to find any aircraft piston engine that can be stopped rotating in flight, other than by switching off the mags or fuel and stalling the aircraft.
This thread is about a Cessna 210. This "discussion" arose out of speculation about the cause of the forced landing of a Cessna 210 and, consequently, fuel management on a Cessna 210.
If you are talking about toys or those devilish contraptions, helicopters, just say so please.