[thenrie]

If your engine needs an overhaul I would take the crank to a machinist and have it repaired. Otherwise, looking at the picture it really doesn't look too bad. I would try replacing the pulley and see if it is snug enough and doesn't rattle on the shaft. As long as the keyway is snug and the set screw is tight, you should be fine. Sometimes when this happens the crank keyway is damaged pretty badly and may need repair, but normally only the pulley's keyway is really bad. The pulley is softer than the crank steel, so it gets most of the damage. Always try the cheapest thing first. You're going to have to replace the pulley, anyway, so start there.