Idle exhaust for marine propulsion systems

摘要

A marine propulsion device comprising a propulsion unit including an internal combustion engine including an exhaust gas outlet, and a lower unit connected to the engine and including a rotatably supported propeller intended to be at least partially submerged in water, an exhaust gas discharge outlet intended to be submerged in water when the engine is operating at low speed, an exhaust gas duct extending from the engine exhaust gas outlet to the discharge outlet, an exhaust relief outlet communicating with the atmosphere, and an exhaust relief passageway extending from the engine exhaust gas outlet to the exhaust relief outlet.