Yep sounds like it. With a worn throttle shaft you have a major air leak. It sounds like a new carb is in the future as parts will cost about 2/3 what a new one would and you still have a worn throttle shaft. Are you sure the choke is not closing on you? Governor no problem most of us remove them. Yes polarity does make a difference on the pulser blue wire to A terminal an red to B from the igniter.
LOU