A lawn mower blade spinning but not cutting issue can occur because of several varying reasons. Either the problem lies directly in the blade, which is broken or incorrectly installed, or the engine needs to provide it with energy to spin properly.

Lawn Mower Blade Spinning but Not Cutting

We have compiled here every possible reason that might be causing this problem, as well as some tried and tested solutions. Go through this well-researched guide and learn all the reasons and their simple solutions.

What Are the Possible Causes of Lawnmower Blade Spinning but Not Cutting?

The possible causes of a lawn mower blade spinning but not cutting grass include a damaged or wrongly installed blade, a dull blade, or damaged lawnmower tires. Other possible reasons can be improper tire pressure, a clogged deck, or a broken mower belt.

– The Blade Might Be Damaged

Even though mower blades are quite sturdy, they easily get damaged when used improperly. Hitting a particularly hard object like a rock while mowing will bend the blade, making it unfit to mow properly.

Use a straightedge to determine if the blade has been bent anywhere along its length. Just hold the straightedge against the blade, and you will see where the blade is bent or broken.

Smaller damages like cracks and dents can easily go unnoticed unless you clean the blade and examine it thoroughly. It’s best to remove the blade from the mower for a closer inspection from all sides. This way, you can hold the blade at various angles under proper light and not miss even the smallest nicks or kinks. 

– Incorrectly Installed Blade

Lawnmower blades have one smooth side and one cutting side. The cutting side always needs to face down toward the grass, while the smooth side should be toward the mower deck.

If the blade is installed the wrong way by accident, then it will only spin but not be able to cut grass. Refrain from installing the blade upside down, as this is a common mistake for beginners and is easily corrected. 

– The Tire Pressure Is Not Right

When the pressure within the lawn mower tires is unequal, a disbalance will be created in the mower. When that happens, the lawnmower blade will naturally be tilted and not cut the grass properly. It usually keeps spinning without cutting through the grass unless the balance is restored. 

If you fill the tires with air, it is possible to fill each tire differently. Another possibility is that the tires have been set at different heights by mistake. Again, the lawn mower and its cutting blade are tilted towards one side.

Reasons Lawn Mower Blade Not Cutting

– The Blade Is Not Adequately Sharp

It is common for lawn mower blades to become dull over time due to frequent use. This happens fairly often and is usually why the mower cannot cut grass properly despite spinning at its usual speed.

Cutting grass blades that are coarse in texture also dulls mower blades faster compared to finer grass varieties. Mowing grass is more difficult using a dull blade, and the lawn also looks far worse than using sharp blades to cut.

– Lawn Mower Tires Are Damaged

If one or more tires of the push type or riding lawn mower are damaged, the balance of the whole mower gets tilted. Either the cutting blade spins without cutting or cuts the grass blades unevenly. You may face difficulty moving the push-type mower forward, and the engine of the riding mower will have to do double the work moving it forward. 

– Dirty Mower Deck Prevents Cutting

The entire purpose of a lawn mower deck is to protect both you and the mower’s engines from the flowing grass debris.

Over time, each mower’s deck gets filled with more and more debris and eventually becomes clogged. This occurrence is more common when people cut wet grass, which is prone to get clumped together.

What happens is that a clogged deck reduces the airflow that is responsible for lifting grass straight up before cutting. When this airflow is decreased, the grass does not stand straight and gets cut unevenly. The blade is spinning but not cutting grass as it should be.

– The Mower Engine Is Not Fast Enough

Often there is something wrong with the lawn mower’s engine, and it becomes unable to provide the appropriate level of energy to the blade. As a result, the blade spins but is not fast enough to cut grass.

This also happens when you keep the mower’s speed when cutting through rough, thick, or tall patches of grass. The engine cannot provide the spinning blade with the extra energy needed to cut through tall grass while carrying ahead at the same speed.

– Broken Mower Deck Belt

The lawn mower deck can wear out with time, especially if the machine is too old and used frequently. This would prevent the mower from cutting grass despite everything being in good condition.

Give the deck belt a thorough manual check-up yourself for signs of wear such as tears, cracks, or frayed edges. A broken belt also produces further tension on the rest of the mower parts, thereby causing damage to other mower parts. 


How To Fix Lawn Mower Blade Spinning but Not Cutting

To fix a lawn mower blade spinning but not cutting, give your lawn mower a thorough check-up and correctly diagnose why the problem might be occurring. You should then correct that particular problem by fixing or replacing the damaged blade and cleaning the lawn mower deck. 

– Replace the Blade if It Is Damaged

If the blade has been damaged, it is impossible to use it again. No matter how much you try to fix a bent or broken blade, it will not work the same way again. Here is a guide on how to replace your lawnmower blade safely.

  1. Turn the mower’s engine off and take the key off, whereas you should take the battery out when using an electric mower.
  2. Check the carburetor, fuel tank, and oil compartment to ensure no spillage as you tilt the mower over on its side. 
  3. Once the mower is safely tilted to its side in a well-balanced manner, remove the bolts attaching the blade to the mower using a socket wrench.
  4. Remove the old blade and replace it with a new one that you can easily purchase from the hardware store. 
  5. Before securing the bolts back, double-check that the blade is placed properly with the grass side facing down.Fix Lawn Mower Blade Not Cutting

– Install Blade the Right Way

It is easy to determine when the blade has been installed incorrectly. Most newly manufactured blades have both sides marked on one corner. Then you can inspect the blade edges to determine which side goes where because the short side is always towards the ground. 

The upcoming steps are similar to replacing a damaged blade. To avoid getting hurt accidentally, disengage the spark plug and turn the mower on its side. Unscrew the bolts holding the blade up and then flip it over. This time, ensure that the short side faces the ground before fixing the nuts and bolts.

– Fix the Tire Pressure of the Mower

Stop the mower, park it to one side and check that all of its tires are on the same level. If one of the tires seems higher or lower than the rest, adjust it so it is the same level as all. Next, it’s time to check the air pressure within all the tires and ensure they are equal.

Most lawn mower manuals specify the required air pressure that should be present within the tires. This is where a tire gauge comes in handy and allows you to determine the exact air pressure levels within the tires. If there is a discrepancy, fix it accordingly and see how the blade starts cutting grass smoothly afterward. 

– Fix Your Blade by Sharpening It

Sharpening the blades constitutes a regular part of lawn mower maintenance and is quite easy to do. 

  1. Take safety precautions by wearing thick rubber gloves and turning the mower engine off completely. As an extra precaution, it also helps to disengage the spark plug.
  2. Remove the blades by unscrewing the screws and attaching them to the mower. It is also possible to sharpen a blade while it is attached to the machine.
  3. You can use either sharpening stones or an electric angle machine to carry out the sharpening.
  4. Put the angle or the stone at approximately 45 degrees to the blade’s cutting edge to sharpen it. Be careful that both edges of the blade are cut equally to keep it balanced.
  5. Once you are done sharpening, clean dirt and grit from the blade using soap and water. Dry it with a paper towel afterwards. 

– Fix Damaged Tires 

It is not uncommon for the tires of a mower to get damaged while working. Before taking the mower out for work, you must remove hard objects such as rocks, stones, and other debris from the lawn. It is also inevitable that tires get damaged from use over time. 

Tires will, of course, need to be replaced by a professional. Many beginners attach tires unevenly, leading to poor cutting by the blade. A professional mechanic will always give you a good discount on new tires in exchange for old ones. 

– Clean the Mower Deck Regularly

It would help if you kept debris from accumulating within the mower’s deck. The one responsibility you can take to save it is regularly cleaning the deck to stop it from clogging over. Before accessing the deck for cleaning, double-check that the mower has been turned off and the spark plug disengaged.

Make a DIY cleaning solution using water and a good-quality liquid dishwashing soap. Use a long-handled brush with this solution to clean all the build-up debris from the deck behind the blade.

For further preventative measures, you should strictly avoid mowing wet grass because it will stick to the deck more. Applying a Teflon-based silicone spray to the mower deck also helps prevent the grass from sticking to it.

– Tighten the Mower Belt

Sometimes, a lawn mower belt needs a little tightening because it has loosened over time. This can be accomplished using either a screwdriver or a wrench only. Adjust the belt on the pulley properly and then tighten it gradually until you feel it is enough. 

Take care not to overtighten the belt over the pulley, or it will end up tearing. It’s best to leave the pulley and the belt system alone if you need help with it; ask someone with experience for help instead. 

– Replace Mower Belt if Needed

If the mower belt is loose, it can be tightened to fix the mower. However, if the belt has been damaged, then there is no option but to replace it. We must warn you that this is a delicate task that requires a certain skill with machines. Call your trusted mechanic because removing a damaged belt is complicated.

treatment of Lawn Mower Blade Not Cutting

If you want to do this yourself, start by loosening the tension from the belt using a tension adjustor. Tension can also be relieved by removing the springs attached to the mower.

When the old belt has been removed, put the new one in, adjust it on the pulley system, and then tighten it. Again, this sounds straightforward but is much more complicated in practice. 


A lawn mower is essential to keeping a well-maintained lawn, and sometimes it stops cutting grass despite the blade spinning.

Here is a recap of all the possible reasons why the blade might not be cutting grass.

  • The blade often gets damaged either from use over a long time or by striking hard objects during mowing. A damaged or wrongly installed mower blade will only spin but not cut grass.
  • This problem also occurs when there is a problem with the lawn mower belt and pulley system.
  • Wet grass and debris clog the mower’s deck over time, eventually preventing the spinning blade from cutting more grass.
  • Some solutions you can try when faced with this problem include replacing the blade, fixing the tire pressure of the mower, tightening the mower belt, or sharpening the blade.

It is common to find that your mower cannot cut grass despite the engine running smoothly and the blades spinning. With the help of this comprehensive guide, you will be able to find the cause responsible in no time and then solve them as well. 

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