Exhaust timing control device for a two-cycle engine

摘要

An exhaust timing control device for a two-cycle internal combustion engine, in which a valve member functioning as the upper edge of an exhaust port that opens into the inner circumference of a cylinder is disposed in the upper wall of an exhaust passage from said exhaust port. A valve hole having an elongated cross-section is opened in the wall of the exhaust passage in the vicinity of the exhaust port, and is formed at an inclination with respect to the axis of said cylinder. The valve member is arranged slidably in said valve hole so that it can be retracted into said valve hole until the leading end portion thereof becomes substantially coextensive with the inner wall surface of said exhaust passage.