| 摘要 |
PURPOSE:To prevent an oil pan from being heated by exhaust effectively by isolating the wall surface of an exhaust passage from that of the oil pan, and also isolating exhaust reaching an exhaust port from the exhaust passage so as not to be in contact with the wall surface of the oil pan. CONSTITUTION:An engine 10 placed on the upper casing 12 of a propulsion unit is covered with a cowling 14. An oil pan 34 is enclosed at an upper part in the upper casing 12, and an exhaust pipe 35 from the engine 10 passes in the vicinity of the oil pan and is extended downward so as to be communicated with an exhaust expansion chamber 38. The expansion chamber 38 passes a lower casing 16 and is communicated with an exhaust port 40 formed at the boss part of a propeller 22. In this case, the wall surface of the exhaust pipe 36 is isolated by the specified distance from the wall surface of the oil pan 34, and an air layer is formed between both of them. The lower end part of the exhaust pipe 36 is supported on the way in the liquid-tight state by a seal member provided between a lid body and the exhaust pipe 36. |
