Hi there Colin, I went racing this sunday and i also had the same problem someone above talks about
. The motor (new EA monster stock) cut out after just 3 laps almost like a sticking brush. I droped out of the heat and looked over the motor and nothing looked wrong so i took the brushes out and there wasnt any burning and diss colour on the com or brushes. So i just com sticked the brush faces and cleaned the com and poped it back together. It ran fine after. Maybe the brushes or com have a coating to protect them in transit and storage.
Nothing wrong with the motors, I think there great but i think people should maybe just pop abit of motor cleaner on the com and brushes before u run for the first time.