You can rebuild them as many times as you want unless the linkage & shafts get worn out, which isn't very often on that carb. Those are so simple. You can take the top off & check the needle & seat & float. Any time a carb floods over too much fuel is getting by the needle & seat. It is usually a piece of dirt in it but can be a bad float or too much pressure like #43 says. The 60 up carbs had the fuel line going in the side & a different air filter mount.
