Don't run the engine again until it's fixed. Once you've got the old balancer off, inspect the inside of the hub and the crankshaft snout. If the wobble is coming from the crank/balancer junction and not the outer ring, there might be some wear on the crankshaft snout that will require replacing the crank. If the wear is minor, you might get by with using red LocTite on the crank/hub interface and the center bolt. Good luck!
Jerry