Patent ID: 9664100
Date: 2017-05-30
CPC Classifications: B63H,F01N

Claim:
1. An outboard motor comprising: a four-cycle engine having a cylinder block provided with a plurality of cylinders extending backward in a travel direction and vertically arranged side by side, and a cylinder head being arranged in a rear end portion and combined with the cylinders of the cylinder block to form each combustion chamber and provided with exhaust ports connected to the combustion chambers; an engine holder that supports the four-cycle engine and connects the four-cycle engine to a lower unit; an exhaust manifold having a plurality of first openings connected to a plurality of the exhaust ports to form a first passage vertically extending; and an exhaust passage having a second passage extending upward along the exhaust manifold, a third passage that is connected to an upper end portion of the second passage and passes above the exhaust manifold, and a fourth passage that is connected to the third passage, turns over downward, and then extends downward along the exhaust manifold, so that a lower end portion thereof communicates with a fifth passage provided in the engine holder, the second, third, and fourth passages being arranged in one side of a left-right direction of the cylinder block, wherein an exhaust gas cleaning catalyst is installed in a middle portion of the second passage, and wherein the exhaust manifold that forms the first passage is interposed between the second and fourth passages, so that the second passage is arranged in a front side of the exhaust manifold in the travel direction, and the fourth passage is arranged in a rear side of the exhaust manifold in the travel direction.