| 摘要 |
<p>A marine propulsion device (10) comprises a water cooled internal combustion engine (16, Fig. 1) and a gimbal housing (18) mounted on a boat transom (14). The gimbal housing (18) has at its front end, an exhaust opening (74), and adjacent thereto first and second exhaust relief openings (76, 78). An exhaust conduit (82) communicates between the exhaust opening (74) and an exhaust outlet (80), and first and second exhaust relief passages (84, 86) communicate between the first and second exhaust relief openings (76, 78) and the atmosphere. An exhaust system (66) communicates between the engine (16) and the openings (74, 76, 78) for conducting exhaust gases and coolant water away from the engine 16, the conduits (70) being so shaped that the water flows along a central passage (88) (in communication with opening (74)) due to gravity and centrifugal force while exhaust gas can be conducted away through passages (102, 104) which communicate with openings (76, 78) whereby back pressure on the engine (16) is reduced. <IMAGE></p> |
