Patent ID: 6196888
Filing Date: 2001-03-06
Classification: B63H,F01N,F02B

Abstract:
An outboard motor for a watercraft, comprising:an internal combustion engine having a crankshaft;a drive shaft extending generally vertically;a propeller shaft extending generally horizontally and carrying a propeller at its one end, the propeller shaft operatively connected to a lower end of the drive shaft;a clutch system disposed between the crankshaft and the drive shaft for drivingly connecting the crankshaft to the drive shaft only when crankshaft rotation speed is higher than a prescribed rotation speed;an exhaust pipe having one end connected to an exhaust port of the internal combustion engine and extending generally vertically so that the other end thereof is submerged under water in an operable state of the outboard motor, the exhaust pipe provided with an exhaust vent which is positioned above a water level in an operable state of the outboard motor so that atmospheric air can enter the exhaust pipe through the exhaust vent when a pressure in the exhaust pipe becomes negative;a stern bracket to attach the outboard motor to a transom of the watercraft; andan engine cowling for covering the internal combustion engine, wherein the exhaust vent is positioned inside the engine cowling and above a surface of the stem bracket contacting an upper end of the watercraft transom in a state that the outboard motor is attached to the watercraft transom.