An internal combustion engine design where intake, compression, combustion, and exhaust occur in a single crankshaft revolution. Because it fires on every downward stroke, it offers a high power-to-weight ratio. These engines typically use ports in the cylinder wall instead of poppet valves and often require oil mixed into the fuel for lubrication.
Heard on the job
The portable generator uses a two-stroke motor, so don't forget to mix the oil into the gas can.
Also heard as
- two-cycle
Related terms
Piston
A sliding cylinder that moves back and forth inside a hollow tube to compress fluid or transmit force.
Poppet valve
A directional valve consisting of a flat disk on a stem that lifts away from its seat to permit flow.
Trunk piston
A long, hollow piston that connects directly to the connecting rod.