Hello all I have a 99 motorguide 43lb thrust 12 volt motor. When i put it on #5 and #4 speed it goes for a couple of secs and then kicks off. If i let off of the throttle switch for a couple secs it will work for a little bit then kick off again. I think the rotary speed control is going out but am not for sure how to prove it. any help or other ideas of what to look at would be greatly appreciated.