Bolar quote: "I would figure with out the fly wheel effect of the prop you could blow/burn up the engine pretty easy."

It will spin really fast and revs quick. The main thing affected is the bottom end. Won't run much below 4000 rpm without the flywheel effect of the prop. It is also easy to pull down the rpms when you load it by pressuring the polishing cloth. I won't run it for an extended time due to the loss of air flow for cooling.