What is two stroke?

Answer 1

A two stroke engine means that the piston makes two strokes to complete a firing cycle. Air and fuel is introduced into the cylinder through intake ports in the cylinder wall. Exhaust gasses are expelled through other ports in the cylinder wall. These ports are opened and closed by the piston moving up and down. When the spark fires the fuel it forces the piston down. On the way down the exhaust port is opened and exhaust gasses leave the cylinder. As the piston continues down it opens the intake port and allows fresh air and fuel in. On the way back up the piston closes off the ports and compresses the new air and fuel charge and the cycle starts over again. One down stroke and one up stroke = two strokes. For a better answer see commercial website howstuffworks, they also have an animation which clarifies beyond doubt what it is and how the two stroke technology is different from a four stroke technology