Small engine for power tools

摘要

A small engine for outdoor power equipment wherein fuel is pumped to the engine's combustion chamber by a reciprocating piston. A desired rate of reciprocation is determined with the engine under load, e.g., with a grass trimmer cutting grass. Avoidance of undesired engine racing is accomplished by restricting airflow to the carburetor which prevents significant increased reciprocation over that desired when cutting. A choke mechanism is provided with a pair of end portions, one of which closes air to the carburetor for starting and the other provides a spaced barrier for inhibiting blow-back. The one end portion includes an inset that seats in the opening through which air enters the carburetor for providing rigidity and to insure closing.