The 2-way exhaust system is used for the main muffler to enhance engine output while ensuring quietness. A control valve is used inside the main muffler to open the exhaust gas passage using the exhaust gas pressure. The control valve is closed by the return spring when the engine is idling or running at low speeds.
The No. 1, No. 2 and No. 3 chambers are used as expansion chambers when the engine speed is low, and the No. 2 and No. 3 chambers are used as resonating chambers when the engine speed is high, ensuring both quietness and high engine output.
|*a||No. 1 Chamber||*b||No. 2 Chamber|
|*c||No. 3 Chamber||*d||Control Valve Closed|
|*e||Control Valve Open||*f||These illustrations are examples.|
|Exhaust Flow (When Control Valve is Closed)||Exhaust Flow (When Control Valve is Open)|