I am sure the very large producers of flywheel mags for most engine could easy do so. But the reason they do not is because they want /need enough weight in a flywheel to make it possible to start most engines. The flywheel once put into motion keeps the spinning motion long enough to keep the engine going smooth enough to start. Also a certain amout of flywheel ...makes for a smoother Idle.

Take your lawn mower blade off your recoil start lawn mower & try to start it...you will know what I am talking about............................................. ......Capt,n