ok, it looks like some people here are confused so here is a pic of what i did.
i used a RED ZIP ZAP MOTOR. just solder leads onto it and put it in. you will either have to drill a hole or cut the pcb cover so the motor will fit because the motor is longer. Don't forget to change the pinnion gears too, make sure you put the pinnion gear that is on the stock motor onto the new motor.
colin