The Engine

Hello, It's Andrew! Today I will tell you how an engine works. The main part of an engine is the PISTON. there are different models and sizes of engines so a piston generally looks like this:

The piston is cased in a CYLINDER The cylinder looks like this:

This is upside down.

Gas is regulated into an engine by a CARBURETOR. It looks like this:

In the cylinder, gas is let in through VALVES. the gas is ignited by a SPARK PLUG It looks like this:

When you pull the string on a lawn mower, it turns the engine, swing with the piston(s) are 4 magnets. 2 are spinning on a wheel and 2 are stationary. This is called a MAGNETO. When the magnets go past each other, it creates electricity, this electricity travels through a wire to the spark plug. This spark ignites the gas creating an explosion, shoving the piston down in the cylinder. This force  brings it back up and when the magnets fly past each other, the cycle starts again.  

At the bottom of the page is a more detailed video of  how a 4 stroke and 2 stroke engine works.