Hey, i was just out running my car in the street, i got a hpi sprint, and the engine just stopped working.... when i hit the gas, the little pinion on the engine doesnt even attempt to turn, just stays still... I changed batteries and still had the problem. I checked to see if a rock was blocking the drive train, nothing there but a small piece of a leave... I rmoved that and still did it... i dont know what to do!! Plz help!