PURPOSE: To prevent ambient water from entering into an engine when a stern is sunk by providing an exhaust side ridge for preventing cooling water flowing through a muffler exit to the inside from entering into a muffler entrance, which has a release port isolated from the entrance and exit to the perpendicular direction.
CONSTITUTION: An expansion chamber 130 having an expansion chamber exit 134 at the upper end 132 is isolated from a muffler exit 128 to the perpendicular direction with the height or perpendicular length of the expansion chamber 130. The expansion chamber exit 134 defines the upper end of an exhaust side ridge 135 isolated from the exit 128 to the perpendicular direction to define a protection zone between the expansion chamber exit 134 and the muffler exit 128. Additionally, the expansion chamber exit 134 is isolated from the muffler exit 126 to the axial direction. As a result, when a hull and a jet unit are under a water level, ambient water entering from an exhaust port to an exhaust device 72 is prohibited from moving through the muffler entrance 126 to a power unit by the exhaust side ridge 135.
CHIYAARUZU BII HOORU
EDOWAADO KEI RAMU
DEYUEIN II ROJIYAASU
