Here's why:
* Four-stroke engine: This refers to the engine's cycle, which has four distinct strokes: intake, compression, power, and exhaust.
* Single-cylinder: This means the engine has only one cylinder, where combustion takes place.
* Spark plug: The spark plug is responsible for igniting the air-fuel mixture inside the cylinder, initiating combustion.
Therefore, a four-stroke, single-cylinder engine needs one spark plug to ignite the fuel in its single cylinder.
