Exhaust arrangement for a 2-cycle engine

摘要

An exhaust port is formed in the wall of a cylinder of a 2-cycle engine. At least one of the portions of the cylinder wall which define two vertically opposing edges of the exhaust port is projected at the circumferentially mid portion towards the opposing edge so as to provide a piston guide surface which conforms with the inner peripheral surface of the cylinder and which extends in such a manner as to reduce the axial height of the exhaust port. The piston guide surface serves to suppress vibration and noise caused when an upwardly moving piston falls into the exhaust port.