How Does 2 Cycle Motor Oil Work?

Most weed trimmers have two-cycle engines.

In weed trimmers and other small engines, two-cycle engines require different oil and different procedures than the four-cycle engines used in cars and lawn tractors. A mixture of a specially blended oil is blended with regular unleaded gasoline to create an enriched mixture that does more than just fuel the engine.

Oil and Gas Mixture

Gasoline is mixed with two-cycle oil at a certain ratio. The common ratios are 40 parts of gasoline to one part oil and 50 parts of gasoline to one part oil. This new fuel is thicker than gas, which allows the motor to do more things at once.

Lubrication

Two-cycle oil lubricates the engine while it also provides the fuel. Smaller engines can be made with two-cycle motors because they require fewer chambers to do the same job.

Fuel Moving into the Crank

As the oil and gas mixture enters the crankcase from the carburetor, it pushes the piston up, causing a spark.

Sparking the Fuel

The spark ignites the fuel, sending the piston downward. This creates power in a two-cycle engine. Four-cycle engines need more rotations to do the same job.

Smaller Engines

With the oil and gas already mixed, the engine does not need multiple storage tanks to house each liquid. This allows the motors to be smaller, which is perfect for lawn and garden equipment like chainsaws that need small engines to be usable.

References

• Steve's Old Engine Shed: Basic 2 Cycle Theory

Resources

• Southern Skies: A Running Two Stroke Engine