I'm kinda new at this conversion game myself. Correct me if I am wrong, but if the engine ran smooth in it's original configuration ( i.e. in the weedeater or chainsaw ), shouldn't the original balance be kept after machining the fins off whether it was heavy on one side or neutral ? I thought some were heavy on one side of the flywheel to help counteract the weight of the rotating mass of the crankshaft of the single cylinder engine.