Then the cam isn't causing the problems because the O/L of that cam isn't much at all. I'd be looking into the carb-related problems that may be causing it that I listed above. There's a reasonably good to very good chance that a rebuild will cure it. Add a float if there's any question as to the condition of the old one and you should be A-OK.
Might be worth it to check the pressure on the carb side of your regulator to be sure it's working as it should.