| 摘要 |
PROBLEM TO BE SOLVED: To form an expansion chamber with the low cost by forming the expansion chamber, formed on the way of an exhaust path for idling by an upwardly extending wall integrally formed on an inner bottom of a bottom cowling covering a lower part of an engine, and a plate-shaped cover fixed to an upper edge of the wall. SOLUTION: An exhaust system of an outboard motor 1 comprises a main exhaust path 11, formed in an upper casing 3 and an exhaust path for idling 12 connected to an upper rear side of this path 11. The exhaust path for idling 12 consists of an exhaust duct 13, an expansion chamber 14 connected to its upper edge, and an exhaust pipe 16 for communicating the inside of the expansion chamber 14 and an exhaust port 15 of an apron 9. Here, the expansion chamber 14 is defined by a wall 18 upwardly extended at a central part in the lateral direction of an inner bottom of a bottom cowling 8, and a cover 20 fixed to an upper edge of the wall 18 by a means of a bolt 19. The exhaust duct 13 is connected to a front side and the exhaust pipe 16 is connected to the rear side, with respect to the outboard motor of the expansion chamber 14. |
