It's called a two-stoke engine because there is a compression stroke and then a combustion stroke.

The second thing you'll notice is how one combustion stroke is ending right when the next combustion stroke is ready to fire.

Moreover, this always leaves a one-piston gap between the piston on its combustion stroke and the piston on compression.

This results in a less efficient combustion stroke, especially at lower RPM.

Then the exhaust valve would open right as the piston bottoms out at the end of the combustion stroke and would close as the piston completes the exhaust stroke.

But remember, the output shaft spins three times for every complete revolution of the rotor, which means that there is one combustion stroke for each revolution of the output shaft.

The flywheels store energy on the combustion stroke and supply the stored energy to the mechanical load on the other three strokes of the piston.

Inserted into the fuel line was a check valve which kept the fuel from running back to the tank between combustion strokes.

Something on the order of 10 milligrams of gasoline per combustion stroke is all it takes!

There are many different parts of an engine's design that control the amount of power you can extract from each combustion stroke.