Are you sure your esc is plugged in the propper rx channel, or in the right polarity? One thing you can try(with caution) is to swap the steering and the throttle into each other(make sense?) so that when you give it throttle the it will give you steering, and when you give it steering it will give you throttle. This will allow you to see if the rx is working properly. If it the steering is working(ie throttle), but the throttle is not(i.e. steering), then you remote isnt working properly i.e. the potentiomiter of the throttle. Does this make sense?