2stroke

2 strokes of a petrol 2 stroke engine

A stroke refers to the full travel of the piston from Top Dead Center to Bottom Dead Center

The 2-stroke engine completes its cycle with one revolution of the crankshaft

stroke 1- up

            Intake

            The air/fuel/oil mixture is drawn into the crankcase from the vacuum created by the piston traveling to TDC The piston is blocking the exhaust and the transfer ports and the intake port is open

            Compression

            The air/fuel mixture that is transferred to the combustion chamber from the pervious stroke is compressed

Stroke 2- down

            Power

            At the top of the stroke the compressed air/fuel mixture is ignited by the spark from the spark plug, the burning fuel expands forcing the piston down the cylinder bore

Exhaust

As the piston travels down it opens the exhaust port and the transfer port and closes the intake port. The fuel/air mixture enters the combustion chamber pushing the burnt gases out