| 摘要 |
PROBLEM TO BE SOLVED: To provide an outboard motor exhaust passage reducing exhaust resistance and preventing bending in the exhaust passage to the utmost. SOLUTION: This outboard motor 1 is provided with an engine holder 3 attached to a hull 2 via a bracket 3, an engine 6 set up on top of this engine holder 4, and a drive shaft housing 8 set up beneath a lower this engine holder 4, and it is also equipped with an exhaust passage 45 extending in the underwater by way of this drive shaft housing 8 from the engine 6. In this constitution, both first and second exhaust expansion chambers 34 and 35 are installed in the points midway in the exhaust passage 45, and the second exhaust expansion chamber 35 at the downstream side is set up on top of the engine holder 4. On the other hand, an exhaust tube 41 is set up at the upstream side of an exhaust channel 42 so as to make the upstream side opening part 41a become upside, and in this case a position of this opening part 41a should be set to such a line of height where sea water 50 or the like is not penetrated into the second exhaust expansion chamber 35 even if the draft level goes up so much. |
