With both of my motors, I asked that, if possible, they would add weight, rather than remove it from the crankshafts. The Lambda ended up with weights added to the flywheel and fanbelt pulley, but the Augusta had weight added to the pulley, but a small amount removed from the periphery of the flywheel. With more modern, presumably stronger crankshafts, it would probably be OK to remove some weight from the crankshaft itself, if necessary. It's important to have the oil pump working, by the way, to enable the crankshaft to be kept full of oil, the weight of which would have an effect on the engine's balance. My Lambda pistons are a bit too much of a sloppy fit in the bores! Unfortunatley, not just "slightly worn".
Regards, John
