I'm trying to get a Rimfire to run but it won't. I have the Bl-8 speed control and 640 3-cell Lipo. Servos work and speed control has been programmed, several times, but when I give the motor throttle, it turns very slowly, maybe 1 revolution in 3 seconds and makes an awful grinding noise. I have adjusted transmiiter settings, timing, and everything else I can think of but it still does the same thing. I have eliminated a bad lead by disconnecting the motor leads one at a time and with any one lead disconnected, the motor just quivers a little. Bad Motor?