2-Cycle (2-Stroke) Engine
An internal combustion engine that completes a power cycle with two strokes of the piston during only one crankshaft revolution. Requires a mixture of oil and gas.
Small Engine Glossary
Understand your equipment. Browse our comprehensive dictionary of small engine terminology, components, and concepts.
4-Cycle (4-Stroke) Engine
An engine that uses four distinct piston strokes (intake, compression, power, and exhaust) to complete one operating cycle. Uses straight gasoline with oil contained separately in a crankcase.
Carburetor
A device that blends air and fuel for an internal combustion engine in the proper ratio for combustion.
Choke
A valve in the carburetor that restricts airflow, creating a richer fuel mixture needed to start a cold engine.
Governor
A mechanical or pneumatic system designed to maintain a relatively constant engine speed regardless of the load applied to the engine.
Recoil Starter
The pull-cord mechanism used to manually crank and start small engines. Contains a spring that recoils the rope after pulling.
Spark Arrestor
A screen or device located in the muffler designed to prevent flammable debris or sparks from exiting the exhaust system. Often gets clogged with carbon in 2-cycle engines.
Top Dead Center (TDC)
The position of a piston in which it is furthest from the crankshaft. Used as a reference point for setting engine timing and valve clearances.