Intake passage device for an internal combustion engine

摘要

An intake passage device is provided for an internal combustion engine having carburettor (4) communicated with connecting projection (12A3) of an intake port (12A1) of a cylinder of the engine, wherein the diameter of the connecting projection (12A3) becomes smaller toward the inside of the intake port (12A1). A connecting pipe (120) is provided for communicating the carburettor (4) with the intake port (12A1). An inner end of the connecting pipe (120) is engaged in the connecting projection (12A3). A communication passage (121) is formed in the connecting pipe (120) for communicating an inside of the connecting pipe (120) with a space between an inside wall of the connecting projection (12A3) and an outside wall of the connecting pipe (120).