How Things Work

Published on July 20th, 2016 | by Brandon


How 2-Stroke Engines Work

What is a 2-Stroke Engine?

The primary difference between 2-stroke and 4-stroke engines is that 4-stroke engines have four cycles for moving burned/unburned mixtures rather than only two. 2-stroke engines are typically very simple and light weight. Because of this, they are commonly used instead of 4-stroke engines in handheld power equipment. 2-stroke engines have very few working parts and require very little maintenance because of this. They are much cheaper to manufacture than 4-stroke engines. They do not have valves or specified lubrication systems.

Main Components:

  • Piston
  • Spark Plug
  • Combustion Chamber
  • Crankshaft
  • Connecting Rod
  • Intake Valve
  • Exhaust Valve
  • Cylinder Head

How it Works:

  • A precise mixture of fuel and air is created in the carburetor
  • The fuel and air mixture is brought into the main cylinder and compressed (compression stroke)
  • The spark plug fires at maximum compression which causes an explosion that drives the piston downwards (power stroke)
  • When the piston is nearing the end of its stroke, the exhaust port is uncovered (power stroke)
  • The pressure in the cylinder drives most of the exhaust gasses out of the cylinder through the exhaust port (power stroke)
  • As the piston hits the bottom, the intake port is uncovered and more fuel and air and pulled into the main cylinder to repeat the process (compression stroke)

Maintenance Tips:

Featured Parts:


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One Response to How 2-Stroke Engines Work

  1. Tamera Mayta says:

    I appreciate your website, sir. Easy reading I just wish their was a cartoon or an illustration for “my need to know” nus. I am sure it will be learning made easy, from what I have seen.
    Thank you

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