If you push on the gov arm with it running, does it resist? Or just move easily, with the only tension being from the spring from the throttle? The gov basically pulls back against spring tension to hold back the throttle plate as speed comes up, settling at a point of equilibrium (advancing the throttle puts on more spring tension, causing the gov to balance at a higher rpm. If the speed slows, the gov holds back less, the throttle plate opens, and it comes back up to speed and so forth). If the gov has failed internally, it can't hold back, and the tendency will be to overspeed. Changing a gov is not that bad, but will require opening the engine case if needed.
