Dull lawn mower blades are a common problem we all face at some point in our lives. It is either because you have been using the blades for too long without sharpening them, or you have yet to check its oil and filter, or due to other reasons.

Dull Lawn Mower Blade

If you need to know which of these reasons applies to your dull blades, our experts are here to help you.

Read on as we inspect each of these causes separately and help you resolve the crisis once and for all.

What Are The Reasons You Have Dull Lawn Mower Blades?

The reasons why you have dull lawn mower blades are they may not be sharp enough, or because you have not turned it on for a while. It can also be that the blades are not rotating properly, or that the blades are bent. 

There are so many reasons for worn-out blades that it is sometimes difficult to pinpoint the exact reason, but from the given, you should definitely be able to tell the reason correctly.

Sometimes the reasons are so simple that even you can identify them with the most basic lawn care knowledge without getting from a professional. You just need the right knowledge and tools to fix the blade and guide you with the right lawn care.

– Blades Are Not Sharp

Most gardeners are so concerned about lawn care that they immediately notice if something is a bit unusual. If you run your fingers gently along the sides of the blades and notice how you would feel a certain gouge, it is a clear indication that the blades are not sharp enough, and that is why the blade is dull; it has lost its sharpness. 

The most common reason is that you have yet to sharpen them, or that due to multiple uses, they wore out and need better sharpening. Most of the users would only sharpen the blades briefly as the blade does its job, or even if they know the time has come to sharpen the blades, we put it on hold until much later.

Reasons of Dull Lawn Mower Blades

Such worn-out blade rips and tears the grass blades, leading to uneven tips, and a messy structure. Moreover, a dull blade causes stress to the grass, and as a result, you get yellow, damaged grass tips. If your mower is set to the lowest level, it is likely to have a greater impact on the objects, increasing the need to sharpen the blades.

– You Have Not Tuned It On for a While

Machines are often burdened not only in terms of work but also when it comes to the rise in temperature. Even in some cases, this would happen when your mower gets overworked, and it is very likely for the blades to get dull in the process. 

As a result, we often tend to neglect that our machines also need to be turned on once in a while, so that they wouldn’t become dull and weak in their functionality. Although the blades trim your grass normally, they are still light and can maintain their sharpness in the near future.

– The Blades Are Not Rotating

If you have gone through all the possible reasons but have yet to conclude, another common reason for dull blades is that they are not rotating or rotating at a very slow speed; hence they would become much duller in their structure. 

Basically, this would happen when you have turned on the engine, but there is little to no action under the deck, due to the slower pace you have set. What happens, in this case, is the common phenomenon when your mower’s belt has jammed or seized a bearing.

– The Blades Are Bent

If you have a large or rocky lawn, it is common for the blades to hit something hard and bend. When they get bent the sharpness would be lost easily because of the crooked texture that it rolled over, and the blades lose their strength of functionality. 

People often need to pay more attention to this, thinking the blade would be fine, but that is where they need to be corrected. A bent blade is not as sharp as the rest of the blades.

What Are Solutions?

Solutions to fix dull lawn mower blades are sharpening your blades and changing the oil and filter of the machine for a smoother maneuver. On another note, you should also try to fix the belt that has been damaged, and lastly, fix the bent blades. 

– Sharpen Your Blade

You need to make your blades sharp and crisp at the beginning of every new season at least, especially if your lawn is rocky or large. A mower blade does not need to be as sharp as a knife, but the blade’s edge must be denting and groove-free so that it would get the job done pretty well. 

What you can do is create your own lawn mower blade sharpening kit for a unique experience. Moreover, try to examine the blade by tilting your push mower to the side so that the carburetor is facing upwards to prevent any gas spill.

But how to sharpen lawn mower blades, could be a worrying question, as you can easily sharpen your dull mower blades with a bench grinder. Before you get into the process, make sure that you wear your protective gear, like goggles and gloves. 

Start grinding the blade’s edges on the spinning wheel, have in mind that it is loud, and sparks fly everywhere, but it is nothing to worry about as it does not take more than two minutes to sharpen a mower blade. As you have done so, the result will be sharp blades that make mowing very easy, and you will have a neat lawn.

– Change the Oil and Then the Filter

Changing the oil and the filter of the machine is a task that you should make a habit of doing so, and tuning your mower every spring. A simple tune-up has many benefits, like extending the lifespan of the mower’s engine, reducing repair costs, and decreasing emissions by half of what they otherwise are. 

Dull Lawn Mower Blade Solutions

The three main things that you need to touch are the oil, filter, and plug. First, you must start running the engine for a while until the oil has warmed up. This is a necessary step that helps to drain oil later. 

Once the engine has been running for a while, and the oil has warmed up, turn off the engine and drain the heated oil. Make sure to replace your drain plug and add oil when you can see it through the hole.

Replace the spark plug next. You can use a penetrating lubricant if the plug is tight because of rust. Leave the lubricant for about ten minutes before you open it again. Take off the spark plug with the help of a wrench and replace it with a new one. Fix the new plug into its place by turning it with your hand. Your lawnmower blades will work fine now.

– Fixing the Belt Damage

Since the dullness can also harm the belt, this means that the first step towards fixing the belt damage is disconnecting your mower from any power supply. Next up, ensure that the mower is in the correct position for repair, so there are fewer chances of you getting hurt by the blades.

Now that your mower is resting remove the belt guards basically, now you can easily access the belt area, and to have a better look at the belt, remove it entirely. You also need to check for any damage caused by taking off the belt because then you have to replace it, but if it is snapped, the only option left is to replace it. Place the new belt following the previous layout and make sure that the blade is locked in its place correctly, and that it is placed neatly and not in an uneven way.

But if the belt is fine and there is no evidence that the blades are dull or not rotating because of it, the next step is to look for a seized bearing. Now, carefully remove the belt and then remove the defective pulley. These pulleys are mostly fastened to the structure with the help of three to four bolts. 

Remember to remove the pulley and replace it with a new one with the help of a wrench or a ratchet set. After replacing the pulley, check if you need to grease it and then secure it back to its place.

– Fix Your Bent Blade

To increase the sharpness of your dull, you need to straighten it first. Tilt your mower so that it is facing upwards so that the fuel, petrol, or oil does not enter the air filter. After you have turned your mower, remove the bent blade with the help of your tools. 

You need strong support to brace the blade, and once you have successfully removed the blade, take an anvil and gently bend the blade backward. You can always use something equally heavy if you do not have an anvil; if you don’t have one, that is fine. After bending the blade backward, you need a hammer to straighten it.

Now that you have straightened the blade, it is time to sharpen it well. This means, taking one of your filers or a lawn mower blade sharpener to make the edges of your blade sharp, and just make sure that the strokes go away from the blade’s edge. You can even put it on your finger to check the blade balance, but if you are an amateur, we recommend you sharpen mower blades in the presence of a professional.

Recovery Tips for Dull Blades


Understanding why your mower blades are dull and how crucial it is to sharpen them for your lawn care now that you have read our article and have even learned how to solve the issue!

Here is a quick recap;

  • You can avoid dull and worn-out blades if you regularly check the oil and filter.
  • Make sure you do not have rocks or similar hard-shelled objects in your lawn to remove any chances of the blade getting bent and losing its sharpness.
  • If reasons like a bent blade do not justify the blade being dull, your next immediate thought should go towards belt damage and seized bearing.

After reading our advice here, you can now certainly go a long way in fixing the worn-out blades and take the necessary steps timely to avoid any inconveniences in the future!



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