How a Lawn Mower Works – 2024 Review

Cutting grass or keeping the yard neat and tidy are tasks that seem to be uncomfortable and boring for people who are not gardening enthusiasts. However, like them or not, these are tasks that have to be done. Fortunately, in these present times gardening or mowing the lawn does not involve the use of knives and scissors. There is complex machinery available for carrying out all gardening tasks. However, even with the use of lawn mowing machinery, the procedure takes a considerable amount of time. So, you can make this time entertaining by having an idea of the different scientific aspects of how a lawn mower works from within.

How a Lawn Mower Works

Despite the fact that there are different varieties of lawn mowers. A vast majority of these machines share a common engine mechanism and this is called a 4 cylinder engine. Below, you will find an explanation of the internal process of mower engines which will further help you in understanding how a lawn mower works.

The Work Procedure of a Mower Engine

How a Lawn Mower Works

For starting a mower engine, the brake bar of the machine should be held simultaneously while pulling the start cord. The brake bar can be found parallel to the mower handle. Pulling the start cord will start the flywheel. When the flywheel starts spinning, the crankshaft automatically starts moving. Here, it is important to note that the crankshaft is duly connected to the piston within the mower engine. This means that when the start cord is pulled, several important parts of the engine are set in motion.

The spark plug is yet another vital part of the mower engine. This part is specifically designed for lighting gas within the engine which further results in combustion. There are two magnets that power the spark plug and these are fastened to the flywheel. With the flywheel spinning, the agents are carried past the ignition cable at every rotation. The entire procedure creates a magnetic field that is used for powering the engine spark plug.

The 4 Stroke Procedure

Now that you have an idea about the exterior functioning of the mower cylinder. It is time to have a detailed idea of the interior work procedure of a lawn mower. Within the mower, there is the piston that completes the 4 stroke procedure. 

  • The first stroke of this 4 stroke procedure is Intake Stroke. With the piston moving to the cylinder bottom, there is the release of the intake valve which further allows a blend of air and gas to flow into the carburetor. 
  • Post this, the piston gets back to the top of the cylinder and the intake valve closes. Thus, the blend of air and gas gets trapped and compressed into a very small space. It is called Compression Stroke and it is the second stroke of the procedure.
  • The third stroke of the procedure is called Power Stroke and it is at this step that the spark plug fires by making use of the electricity that is generated with the rotation of magnets past the ignition cable. The firing of the spark plug combusts compressed air and gas blend resulting in a small explosion that is enough for pushing the piston to the cylinder bottom. 
  • The last stroke of the 4 stroke procedure is the Exhaust Stroke that takes place mainly when the engine piston gets back to the top of the cylinder by making use of the movement of the spinning flywheel. This is when the exhaust valve completely opens making way for the exhaust that is left after combustion to air and gas mixture to go out of the machine by way of the muffler. This completes the final step of the essential 4 stroke procedure.

4 stroke procedure

With the piston rotating back and forth, there is the stabilization of the crankshaft. The mower blades that carry out the important task of cutting grass are connected to the crankshaft. Thus, when the crankshaft spins, the blades spin as well and the piston remains steady. The blades spin underneath the mower and offer great grass cutting and mowing results. It is important to note that the engine continues the 4 stroke procedure until the user applies the brake. Once the brake is applied, the 4 stroke procedure is interrupted which further prevents the engine to work. Once the brake bar is released by the user, there is a grounding circuit created which further stops the flywheel thus stopping the entire chain reaction that helped the mower engine to function uninterruptedly.

The 4 stroke procedure is a very simple and elegant procedure that completely relies on the different parts of the lawn mower working in tandem to keep the machine working.

Work Procedure of Push Mowers

How a Lawn Mower Works

Almost all the different varieties of lawn mowers work on a similar principle and that is hitting the grass blades at high velocity. However, different varieties of these machines carry out this task in varied ways. Push lawn mowers are the most affordable varieties of these machines available in the market and they are also the simplest. Their basic structure showcases a cylinder enclosing several rotary blades. Human effort is needed for operating these mowers and therefore there is no additional energy required. On pushing the mower, there is the force exerted on the crankshaft and this turns the mower wheels. As the wheels turn, the blades start moving in circles offering the cleanest cuts.


At present, there are robotic mowers available in the market, which work in the form of highly advanced gadgets. These mowers work on rechargeable batteries and do not require any kind of supervision. These machines simply need to be set for mowing a certain part of the lawn and the entire work gets completed in a matter of seconds. The use of advanced technology has helped homeowners and business owners to maintain the beauty and the aesthetics of their properties without putting in a lot of effort.