A single-cylinder motorcycle can have either a two-stroke or a four-stroke engine. The number of strokes refers to the movement of the piston within the engine's cylinder during a complete combustion cycle. Here's a breakdown of the strokes for each type of engine:
- Two-Stroke Engine: A single-cylinder two-stroke engine completes a combustion cycle in just two strokes of the piston:
Upward Stroke: During this stroke, the piston moves upward, compressing the fuel-air mixture.
Downward Stroke: In this stroke, the piston moves downward, ignited by the spark plug, and the resulting explosion forces the piston downward. This stroke completes the power and exhaust phases of the combustion cycle simultaneously.
- Four-Stroke Engine: A single-cylinder four-stroke engine completes a combustion cycle in four strokes:
Intake Stroke: The piston moves downward, and the intake valve opens, allowing a fuel-air mixture to enter the cylinder.
Compression Stroke: The piston moves upward, compressing the fuel-air mixture, which increases its pressure and temperature.
Power Stroke: Once the fuel-air mixture is compressed, it is ignited by a spark plug. The resulting explosion forces the piston downward, generating power.
Exhaust Stroke: The piston moves upward again, pushing out the burned gases through the open exhaust valve.
In summary, a single-cylinder motorcycle engine can have either a two-stroke or a four-stroke design, each completing the combustion cycle in a different number of strokes.