Vent assembly for marine propulsion devices

摘要

The outboard motor includes a powerhead housing defining an engine compartment for an internal combustion engine and a vent assembly for ventilating the engine compartment to the atmosphere. The vent assembly includes a tubular member mounted in an aperture in the housing bottom wall and having an inlet port communicating with the interior of the engine compartment, an outlet communicating with the atmosphere and an interior wall defining a bulbous passage between the inlet and outlet ports. Under normal operating conditions, a buoyant ball valve movably disposed in the bulbous passage is held in an open position by gravity to afford free air flow into and out of the engine compartment. In the event the water rises to a level above the housing bottom wall, the ball valve floats on the water entering through the vent assembly outlet and sealingly engages a valve seating surface to prevent entry of water into the engine compartment.