Does the motor have factory installed capacitors? If not install some (someone can explain how...basically 1 from + to ground, 1 - to ground & 1 from + to -). Try twisting your motor wires and even all wires to the Rx. Try to mount your Rx as far from your motor as you can. Are you running near power lines? That's all I can think of right now. Hope that helps at least a little.