The Four-Stroke Cycle Explained

An internal combustion engine converts fuel into motion. First is the intake stroke.

The intake valve opens and the piston moves down, drawing in a

mixture of air and fuel. Next comes the compression stroke. Both valves close

and the piston moves upward, compressing the mixture. Then, the spark plug

ignites the fuel, creating an explosion that forces the piston downward. This is the

power stroke. Finally, the exhaust valve opens and the piston

pushes the burned gases out of the cylinder. This four-stroke cycle repeats continuously to

produce power.