Patent ID: 7556548

Claim:
An exhaust device for an outboard motor, comprising: an engine having a plurality of cylinders; a first expansion chamber case configured to collect therein exhaust from a first part of the plurality of cylinders; a second expansion chamber case configured to collect therein exhaust from a second part of the plurality of cylinders; and first and second exhaust passages extending individually from the first and second expansion chamber cases, respectively, each of the first and second exhaust passages having a downstream end opening communicating with water, wherein the outboard motor includes a case extending generally vertically and supported on a hull such that a lower part of the case is submerged in water, and a propeller supported at a lower end of the case, the downstream end openings of the first and second exhaust passages being formed in a longitudinal midway part of the case below a surface of the water, the exhaust device further comprising a partition extending in a longitudinal direction of the hull and separating the propeller and the downstream end openings, the partition being supported by the case.