A noise control apparatus for a motorcycle exhaust system. The apparatus includes at least one exhaust pipe assembly having a direct pass-through mode and an indirect mode wherein exhaust gases are optionally directed through noise attenuating means. The apparatus includes at least one valve for controlling exhaust gas flow, a motor, a switch controlling said motor, a wire carrier, a wire connected between the carrier and the valve(s), and a rotary threaded drive shaft driven by the motor for moving the positioner. The threaded drive shaft includes radially extending and circumferentially facing stop means on both sides of said wire carrier. The valve is positioned under the control of the switch.