Patent ID: 7704111
Filing Date: 2010-04-27
Classification: B63H,F01N

Abstract:
1. An exhaust system of an outboard motor which includes a multi-cylinder engine in which cylinders are disposed in a cylinder block in a longitudinally oriented and vertically parallel manner, a cylinder head is arranged at a rearward position of the cylinder block, and a crankcase is arranged at a position in front of the cylinder block, the cylinder head having an outlet of an exhaust port at one side thereof, the exhaust system for the outboard motor comprising: an exhaust manifold which communicates the outlet of the exhaust port with an exhaust discharge opening, the exhaust manifold including a first exhaust gas passage extending in a vertical direction for gathering exhaust discharged from the outlet of each exhaust port and a second exhaust gas passage extending in a vertical direction adjacently to the first exhaust passage; and a catalyst unit provided on a way of the second exhaust passage, wherein the first exhaust gas passage and the second exhaust gas passage are communicated with each other through a communication passage provided at a central portion of the first exhaust passage in the vertical direction, and the second exhaust gas passage is arranged below the communication passage.