Two- and four- stroke engines

This engine differs from the four-stroke engine in having … during each complete revolution of the crank-shaft.

During … of the piston a port leading to the crankcase is uncovered and the explosive mixture of air and fuel is drawn into the crankcase.

The internal combustion … is a machine that develops power from the combustion of fuel within a cylinder.

Just before the piston reaches …, a valve, usually of the “poppet” type, is opened

On its outward stroke, the piston draws into the cylinder an … of air and fuel vapour.

Shortly before the piston reaches the …, the inlet valve is closed and the compression stroke begins. 

During this stroke, the whole of the gas in the cylinder … into the free space at the head of the cylinder. 

When the compression stroke is almost complete, the explosive mixture is ignited by an … or by other suitable means. 

The gases reach their … almost immediately, and work is done until the piston has again reached a position just before the outer dead-centre, when a second exhaust valve is opened.

The burnt gases … out in front of the piston and on its return until the inlet valve again opens, when the cycle is repeated.