A two-stroke engine is a type of internal combustion engine that completes a power cycle in just two strokes of the piston. These engines are widely used in small vehicles like motorcycles, chainsaws, and boat engines due to their simplicity and high power-to-weight ratio.
Here's a simplified breakdown of how a two-stroke engine works:
Intake Stroke: As the piston moves upward, it creates a vacuum, which opens the intake port. This allows a mixture of fuel (usually a pre-mixed fuel and oil blend) and air to enter the combustion chamber.
Compression Stroke: As the piston moves downward, it compresses the fuel-air mixture, closing the intake port. This compression increases the pressure and temperature of the mixture, preparing it for combustion.
Combustion and Power Stroke: When the piston reaches the bottom of the stroke, a spark plug ignites the compressed fuel-air mixture. This ignition causes a rapid expansion of gases, pushing the piston back up with considerable force. This upward movement is what generates power in the engine.
Exhaust Stroke: As the piston reaches the top of its stroke, it opens the exhaust port, allowing the burned gases to be expelled from the combustion chamber. Simultaneously, the piston uncovers the intake port, preparing for the next cycle.
It's important to note that in a two-stroke engine, the intake, compression, power, and exhaust strokes occur in a single revolution of the crankshaft, unlike in a four-stroke engine, which requires two revolutions.
Two-stroke engines are known for their lightweight design and higher power output compared to their four-stroke counterparts. However, they tend to be less fuel-efficient and produce more exhaust emissions due to the nature of their combustion process.
