Did you ever find a solution to this? My Motorguide Varimax does the exact same thing. Today, the motor just stopped on me, again. Has not happened in weeks. No junk around the prop shaft. It will just stop working. Then, it takes 7 - 10 minutes and it starts working again. Happened three...
I have a Motorguide Varimax 55lb thrust wired with handle control. Has worked well for many years. This year, on 3 or 4 occasions, it will simply stop turning. Turning it off/on or unplugging it has no affect.
It seems to reset itself after about 7 or 8 minutes and then it starts...