Converted a husky 57cc chain saw engine (partner). I used the original mag flywheel. I cut it down and added a machined prop adapter fastened with three axial bolts. This the scary part, on the first run I was reving the engine (23x8 prop) and suddenly a loud bang. The original mag wheel had disintegrated. Found the mag wheel had a steel center with about 1/4" of aluminum on the outside. The three holes I had drilled and tapped (6/32) were half in the steel and half in the aluminum. Looks like the fastener holes weakend the mag wheel aluminum to steel hub join. Fortunately, no one was hurt. I always insist observers stay behind the prop. Good luck, red