Two-stroke cycle gasoline engine

摘要

A two-stroke cycle gasoline engine including at least one two-stroke cycle power cylinder-piston assembly having two horizontally opposed pistons and incorporating uniflow scavenging, a reciprocating type scavenging pump means including at least one pump cylinder-piston assembly of the reciprocating type driven by the power cylinder-piston assembly in synchronization therewith, wherein the carburetor incorporates, in addition to a normal throttle valve, a control valve which automatically increases its opening as the rotational speed of the engine increases, so that, when it is set to provide its maximum opening at the maximum rotational speed of the engine, it provides gradually reduced opening as the rotational speed of the engine lowers.