Check your belt and make sure you do not have it too tight. If it does not skip a couple of teeth on braking it is too tight. Make sure the motor cooling hole in the body is open. If you are using the old body and not the newer aurora body you will need make a cooling hole. Also, I think that 18 is alittle undergeared for this car. Did you follow the chart in the manual? I would think something like a 19 or 20 would be better. I ran an 19/92 with an orion 11T V2 and the motor ran reasonably cool.