Well, all us exspurts (drip under pressure) have suggestions and you are probably now ready for "the funny farm". Anyway, it sounds like you have to look to the motor hook-up to solve the problem. OK, on the 20amp great plains ESC, sometimes they are undersized so just wanted to confirm that. The Great Planes ESC I have used a Schottky diode so that may be possibility, and a FMA ESC I just bought has one also. So, if you do reverse the leads to the motor you also need to swap diode around to put the band end on the positive (+) lead of the motor. Oops, another post came in while I was typing this one. (same answer). From my experience, the more you get into this hobby, the dumber you become and if you continue you will become infantile, but don't give up.