How do 4-cycle engines work?

4 cycles consist of:

Intake cycle

Compression cycle

Ignition cycle

Exhaust cycle

Intake cycle - piston in lowest position intake valve open allown atomized fuel to enter combustion chamber

Compression cycle - piston in upward stroke compressing atomized fuel mixture All valves closed

Ignition cycle- Spark is introduced to combustion chambeer blowing piston back down in chamber valves closed

Exhaust cycle- exhaust valve open piston rises in chamber to expel spent gasses.