| 摘要 |
PURPOSE:To enhance the assembling property and the cooling performance of catalyst by communicating the exhaust ports of respective cylinders with one another using a collecting exhaust passage, and thereby disposing integrated catalyst at the middle section of a place communicated with the exhaust ports of two cylinders. CONSTITUTION:An engine 12 having a plurality of cylinders 15 is disposed at the upper section of the casing of an outboard motor 1 to be mounted on a hull 2. The exhaust ports 20 of the cylinders 15 are communicated with one another at one side of the engine by a collecting exhaust passage 21. The aforesaid collecting exhaust passage 21 is formed by the outer surface 19a of a cylinder wall and a cover 22 plugging an opening faced to the outer surface 19a of the cylinder wall. The collecting exhaust passage 21 is communicated with an underwater exhaust port 48 by way of an exhaust passage A within the casing. Moreover, integrated catalyst 38 is disposed at a middle section of a place communicated with the exhaust ports 20 of at least, two cylinders 15 within the collecting exhaust passage 21. Thus the aforesaid catalyst can be simply assembled/disassembled, so that the assembling property of catalyst can thereby be enhanced. |
