How to Fix Your Lawn Mower If It Is Not Running at Full Power

Lawn mover

Lawn mowers have always allowed homeowners to cut grass efficiently without wasting much time in the process. These outdoor machines, however, tend to have some lag in speed after longer periods of inactivity. This could be explained by many reasons. But, do you know how to fix a mower that is not running at full power?

Depending on the reason for it slowly running, you may have numerous solutions to this issue. First, you can replace the plug or carburetor of the machine to see if it solves the problem. Otherwise, you could also thoroughly clean the blade or get rid of clogs in various components of the machine to restore its speed.

Before we move on to possible solutions, knowing the exact cause of the slow-down will help you do things properly. This post aims to help you understand the common causes of a mover not running at full power, besides suggesting convenient solutions for the problem.


What Causes a Lawn Mower to Run Slow?

Several things can affect the performance of a lawn mower, and many small parts of the engine could be the reason why yours runs slow. Below are some of the most common reasons for lawn mowers not running at full power.



One of the main causes behind the poor performance of many lawn mowers is blockage or clogging. A typical lawn mower gets its power from the liquid fuel that can ultimately cause you trouble. The combustion engine solely depends on the liquid fuel to generate the energy required to do the job. As a result, you will see blockades in many parts of the engine.

As already mentioned, lawn mowers’ engines consist of many small parts. A trivial clogging in any of them and can alter the engine’s performance in many ways. However, you can check the following three areas to determine if clogging is the cause for your computer’s lag:

  • Petrol line
  • Carburetor
  • Air filter


Before making any decision, you must examine these parts thoroughly. You can follow the suggestions mentioned below to get the job done if clogging is an issue.

First of all, you need to analyze the condition of these parts to see if they need replacement. For instance, gas caps should be replaced if they are in bad shape. Instead of wasting time cleaning those, you can buy a new one at a cheaper rate. However, this does not apply to every part.

It is common for air filters to absorb lots of dust due to high-end usage. You cannot replace them on every use. That is why you should try cleaning them thoroughly to prevent any blockage and inefficiency. If the filter is too clogged with dirt, compressed air may be a better option. Additionally, you can also clean the foam inside the filter with the help of water and any cleaning agent.

However, we advise you never to forget to disconnect the spark plug before you start cleaning or doing maintenance.

Poor Blade Maintenance

Another thing that can affect the operational efficiency of a lawn mower is the poor maintenance of the blade. Yes, you read that right! Blades are one of the most essential components of mowing devices, after the engine. Without a properly functioning blade, you can do nothing with the grass.

Regardless of the power and efficiency of the engine used on the device, you may end up heating the entire system if the blades are jammed. There are several possible reasons behind the jamming of the blade, such as exposure to dirt, mud, and trivial grass clippings, which can reduce the efficiency of the edges.

The only thing that you can do in this regard is clean the blades thoroughly after completing a task. Doing so will keep the edges sharp and prevent jamming. Thus, blades will not burden the engine since they will require less power to spin.


Low Power Output

One of the most common causes of mowers not running at full power is low power output, which means the plug of your device encounters problems. As the plug is the sole element that produces electric current for ignition, a faulty plug may not provide a constant supply of current. Therefore, you may experience low power output or even no power output at all. The best thing to can do in this regard is clean the plug thoroughly to see if it solves the problem of output. You can also replace the plug if cleaning it fails to yield results.



A carburetor is another part that can affect the performance of any high-quality lawn mower. It is the carburetor that mixes the air and fuel to power the combustion engine. The most common problem with these carburetors is clogging. Due to excessive fuel movement, it is indeed frequent for these elements to show some signs of blockage.

You can do several things to solve this issue. However, try cleaning the carburetor yourself before calling a technician.



Although it seems strange, gasoline can also slow down your lawn mower. Indeed, different gasoline suppliers employ multiple mixing formulas to achieve the final product. As a result, fuel from numerous gas stations may contain different percentages of ethanol, benzene, methanol, and other substances.

The combustion engines commonly used on lawn mowers cannot sustain every type of fuel. That is why we recommend our readers properly read the instruction manual to see if it contains any information on the type of fuel you can fill your lawn mower with. Using the manufacturer’s suggested gas type can help you prevent any speed issues.

However, you can also follow another simple hack associated with petrol to overcome many potential problems. It is never a good idea to leave petrol in a lawn mower for an extended period. Since petrol tends to thicken over time, it eventually clogs and blocks many small engine parts.



Humanity has benefited from the advancement of technology in many ways. The use of battery-powered lawn mowers is not a novel idea. People across the globe are using them to prevent carbon footprint. Despite this, batteries tend to wear out over time. As a result, they may fail to generate an optimum level of output for the machine.

If a battery-powered lawn mower isn’t operating at full power, a new battery could fix the issue. However, you should check for other problems before buying a new battery to replace the existing one.


How to Fix a Lawn Mower Not Running at Full Power?

The optimal solution depends on what is causing the problem. The primary reasons that can slow down the performance of any lawn mower are outlined above. Below are some interesting hacks that can help you solve this problem without contacting a professional.


Replacing the Plug

Before replacing the plug, you can try cleaning it thoroughly to see if it solves the problem. However, if it is completely damaged and shows no signs of revival, replacement is the only option.

As far as cleaning is concerned, you can use compressed air to clean the plug thoroughly. Using compressed air, you can remove all the gunk from the plug, restoring it to its original form. Try to reinstall the plug on the machine after it has dried out.


Dumping the Existing Gas

Old gas stored in the container of a lawn mower can result in the clogging of many components. As a result, it is common for the engine to slow down due to the excessive energy utilized in the process. Before wasting petrol, you can check its quality to assess whether or not it is still usable.

However, you should not forget to remove the spark plug before the removal of the existing gasoline. This precautionary step can save you from the further deterioration of the problem.


Reviving the Blades

Regardless of the model of lawn mower you used, the blades consume a significant amount of power. The regular cleaning of blades ensures that the device runs efficiently. Consequently, they do not require a lot of energy from the engine.

The machine may run slow if the blades are not appropriately maintained. That is why you can try to restore the device’s edges to their original shapes if you want your machine to run more smoothly.


Avoiding Excessive Abuse

Lawn mowers feature exceptional build quality. Yet, if you continually abuse them, they will not function smoothly. Because of this, you should not overload your device. Make sure to clean and maintain it regularly to ensure its flawless functioning over the years.


Replacing the Battery

Battery replacement is the final option for electric grass mowers users. Battery power output slowly decreases over time, which can reduce the speed of your machine. That is why you can try replacing the machine’s battery if all the options mentioned above fail to yield results.



Fixing a slow lawn mower is easier than you think. You only have to diagnose the problem-causing area to resolve the issue quickly. Cleaning and maintaining the machine regularly can also prolong its service life. You can follow the solutions mentioned above to get the job done in no time.

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