Exhaust treatment for outboard motor

摘要

An exhaust system for a marine propulsion outboard drive wherein the exhaust gases are normally discharged to the atmosphere at a point below the level of the body of water in which the watercraft is operating. A catalyst bed is provided in the exhaust system and the catalyst bed is protected from damage by pumping water from the exhaust conduit in response to certain conditions. These conditions may be either rapid deceleration of the engine or watercraft, stopping of the engine, or any of a combination of sensed factors. The water is pumped by a water pump which is positioned either in the outboard drive or in the hull of the associated watercraft. The pumping of water is initiated for only a predetermined time or until the sensed condition no longer is existent.