Patent ID: 8113893

Claim:
An exhaust device for an outboard motor engine including a plurality of cylinders, the exhaust device comprising: an exhaust passage having a first end connected to the engine, and a second end; an exhaust chamber connected to the second end of the exhaust passage and to a main exhaust passage positioned below the engine; wherein the exhaust passage includes: a plurality of upstream portions each provided for a respective one of the plurality of cylinders and having inlet ends connected to exhaust gas outlets of the plurality of cylinders whose exhaust valve opening periods are different; a collecting portion arranged to connect outlet ends of the plurality of upstream portions to each other; and a plurality of downstream portions which are branched from the collecting portion and connected commonly to the exhaust chamber; a plurality of catalysts arranged such that one of the plurality of catalysts is provided in each of the plurality of downstream portions; and nozzles disposed on upstream sides of the catalysts in the downstream portions of the exhaust passage, wherein each of the nozzles has a narrowing portion at which a cross-section area of an exhaust path is gradually reduced toward a downstream side thereof, and an expanding portion at which the cross-section area of the exhaust path gradually increases toward the downstream side between the narrowing portion and the catalyst; wherein the nozzles are supersonic nozzles.