thats not neccisary at all... its just a bonus to a run-in motor. the best and safest way is with an electric starter.

also, what was failed to be mentioned, is to make sure you get the brass o ring off the head before you hit it with the starter, or it will be gone forever.

also, i put blue loctite on the shaft and crank the hell out of the nut when i put them on. never had a problem ever. except when i was first learning, i kept kicking the prop off.