Patent ID: 8721377

Claim:
An outboard motor having an engine and an engine cover adapted to cover the engine, the engine having an air intake passage that opens at the engine cover, wherein the air intake passage includes: an entrance passage that communicates with exterior of the engine cover through a plurality of air inlets that are connected to the engine through the air intake passage; a down-flow passage that is connected to the entrance passage and makes intake air sucked from the air inlets and the entrance passage flow downward in a vertical direction; a reversing passage that is connected to a lower end of the down-flow passage and reverses a flowing direction of the air flowing from the down-flow passage; an intake air silencer connected to the reversing passage; and an intake manifold connected to the intake air silencer through a throttle body, wherein the intake air silencer has two air intake ports whose openings face diagonally backward and connected to an outlet side of the reversing passage; and an exhaust port installed between the two air intake ports and connected to an inlet side of the throttle body, wherein the improvement comprises: a secondary air passage having an inlet disposed at an internal space of the engine cover and an outlet connected to the air intake passage at a position downstream of a throttle valve of the engine.