Never been so confused. Was going to go with Dubcchs weld on option. Four or sex. Then talked to some local shops and they don't recommend it. Problems with the ceramic coating being welded on and other problems. They recommend TY Davis's cure. Complete fly wheels. The shop recommended a 10 oz which according to Dr. D's people is way to much. With Tys system you can easily change the weight. Dr. D according to his people runs a 4 oz. but then he probably has new tires all the time and is on nicely groomed tracks, not the blue groove thacks of Lake Elsinore. Anyone have any info. Never had a stalling problem, just the bike has so much power and wheel spin, that it doesn't hook up like the Honda CR450 does. But I still would only ride a Yamaha YZ450. Hopefully the 10 oz will allow the bike to hook up.