PURPOSE: To prevent rush of splash into a cowling by providing an intake port on a position adjacent to an intake device on the side surface of a cowling main body and opening that intake port in the direction other than the front side of a propelling direction.

CONSTITUTION: The left and right intake ports 19 of a cowling 18 through which the air for combustion of an internal combustion engine 13 is taken in are arranged on the left and right side surfaces of a cowling main body 18A and in positions adjacent to the left and right air intake ports 17 of an intake box 15. At this time, respective intake ports 19 are opened nearly rearward in a propelling direction. Thus, rush of splash in to the cowling can be prevented and the air for combustion with a constant oxygen density can be also supplied in the engine intake device in the cowling smoothly.