Is your throttle control on your radio not set correctly? Maybe when you have it turned on the brakes are engaged and that's why you have to give it a push? In short turn the little knob on your radio that says "Th Trim" to the point where the car sits still while ideling but not too much so it'll still roll freely with out the brakes being engaged. I'm not sure if that's your problem or not but it could be a possibility.