Using this Unique Cutaway (Cut in half) Chainsaw, I Explain how A 2-stroke chainsaw engine is an amazing combination of power and simplicity that is ideal for heavy-duty cutting jobs and tree felling. 2-stroke engines are small and light, completing a power cycle in just two piston strokes, in contrast to their 4-stroke counterparts. Once you blend fuel and oil in a precise ratio—usually 50:1—and pour it into the fuel tank, the magic begins. The engine roars to life the moment you pull the starter cord.

The compression and ignition strokes start the process inside the engine. The fuel-air mixture in the cylinder is compressed as the piston rises. This mixture is subsequently ignited by a spark plug, producing a flaming explosion that exerts tremendous force on the piston. The chainsaw gets its power from this downward action. Precision cutting of wood is made possible by the crankshaft being turned by the piston's descent.

The 2-stroke engine doesn't spend a stroke on venting burnt gases, though, which is the twist. Rather, the exhaust stroke is the upward motion of the piston, which forces the exhausted gases out of the cylinder through ports near the top. The entering fuel-air mixture is drawn into the crankcase concurrently. The cycle is repeated when the piston rises again and compresses this new mixture. Chainsaws are an essential tool for both outdoor lovers and lumberjacks because of their clever design, which produces raw power despite being less fuel-efficient and more polluting than 4-stroke engines.