What causes a riding lawn mower to cut uneven?


We use a riding lawnmower to cut our grass so that the result looks beautiful and attractive. To make a lawn look good, an even cut is needed. If the grass is cut unevenly, it will look a bit untidy. For that reason, it is important that your lawnmower cut grass evenly. But what about a lawnmower that does not cut evenly? There can be various reasons why this is happening. This blog will look into the different causes and how to fix them.

What causes a riding lawnmower to cut unevenly?

If a lawnmower does not cut evenly, the most probable cause is mower deck damage and misadjustment, resulting in an uneven cut. To fix the problem, several things need to be checked:

  1. The Tire Pressure.
  2. Is the mower deck leveled?
  3. Is the deck clogged?
  4. Mowing to fast can results in unsightly stripes.
  5. A Dull and damaged blade will give an uneven cut.
  6. Unbalanced blades.
  7. Worn deck pulleys cause the blades to vibrate.
  8. Overlapping row mistakes can result in uneven cut grass.
What causes a riding lawn mower to cut uneven? 1
(CC BY-SA 2.0) by Chuckcars

Steps to fix the Riding Lawn Mower to cut uneven:

The lawnmower cutting uneven grass may have some issues, and it can be fixed quite easily. This may be because of the operating system, cutting blades, and uneven weight distribution. Following are the leading causes of cutting uneven grass and the troubleshooting steps to resolve the respective issues.

● Step 1. Tire Pressure may cause this issue.

Under inflating and over-inflating can bring plenty of wrongs in steering and mowing. It makes the mowing deck sit unevenly. If the mowing deck is uneven, then the grass cutting will also be rough.

– Solution:

To avoid this, check the inflation of all the four tires of the riding lawn mower before starting because over and under inflating tires may cause the grass to cut unevenly.

● Step 2. If the mower deck is not leveled, then it will cut uneven grass.

While riding a mower, sometimes, it hits the bumps and debris that make the desk height misadjusted. However, sometimes while changing blades, the desk level is also disturbed. If the desk is not leveled, then you may face this issue.

– Solution:

Leveling the deck under the mower is very important to cut the grass more precisely. It would help if you dropped the mower deck to avoid uneven cutting. You should check the heights of the desk before and after changing the blades to remain adjusted.

● Step 3. The clogged deck may also cause this issue.

Simultaneously, cutting the grass and debris build under the deck, especially when it is wet. This causes to cut the grass uneven.

– Solution:

If the mower deck is clogged, you should clean it at once as it causes hindrance in the blade, so it should be adequately cleaned. It would be best if you cleaned the grass clippings from the desks and then start moving again.

● Step 4. Fast mowing results in unsightly stripes.

We all want to save time, which is why we try to finish tasks as soon as possible. This often applies to mowing as well, and we try to mow at the highest speed. Depending on the power of your riding lawnmower and the height of your grass, this is sometimes possible. But when the amount of grass that needs to be cut is too much, the speed can hurt the cutting, resulting in an uneven cut lawn. The solution is easy. When you notice uneven or rough cut grass, lower your mowing speed.

– Solution:

Take your time in mowing the grass and never rush while riding a lawnmower. In this case, you should cut the grass steadily and correctly to get good results.

● Step 5. Dull and damaged blades cut the surface uneven.

The primary source of cutting the grass is the blades used in the lawnmower. If the edges are dull and damaged, then obviously, they will not miss the grass properly. If the blades are damaged, they can be sharpened by you or a professional. If the edges are not sharpened, then they will cut the grass unevenly. 

– Solution:

It would help if you used sharp and straight blades. If the edges are damaged, you should replace them with new ones.

● Step 6. Unbalanced blades are not suitable for cutting the grass.

If the edges are not parallel, they won’t catch the grass falling in the maximum clearance area between them very well and cause uneven cutting.

– Solution:

You should check the blade balance as well and make them synchronized if they are cutting rough grass. Balance the unbalanced blades by using the angles specified in the manufacturer’s manual.  

● Step 7. Worn deck pulleys cause the blades to vibrate.

The vibration of blades causes unevenness.

– Solution:

To avoid vibration, replace unbalanced blades and worn pulleys.

● Step 8. Overlapping row mistakes can result in uneven cut grass.

If the person operating the lawnmower is not experienced and is not overlapping the rows enough, this may happen. The shapes of the blades are made in such a way that they pull the grass upward. On the other hand, while mowing, the machine pushes it downwards. If the person overlaps the row into the previously overlapped row, then the under do not get a chance to be cut. Blades do not reach the very edge of the mowing deck.

– Solution:

Overlapping every row for several inches is necessary while cutting the grass. Overlapping is necessary. Overlap your passes so that they do not cause any unevenness.

For a hands-on demonstration of how to fix this issue, you should watch this video:

Safety Precautions:

Always take care of the safety precautions before starting repairing. You should turn the unit off and remove the keys before starting. Use hard leather gloves while changing, balancing, or repairing the sharp blades. Do not leave the guards or deflectors off when you are done. Always take care of safety precautions and keep yourself safe from any incident. It is now up to you to implement the various suggestions to cut it more precisely with the best safety measures you should avail.

Frequently asked questions

1. The blades are balanced still it’s not working, what to do?

The balancing of blades is essential to cut the grass precisely. If you have already checked and balanced your edges and still face cutting the grass right, there might be some other issues. The blades are not sharpened. Better sharp you blades or if they are damaged replace them with the new one. These blades are the primary source of cutting the grass. If these are not in good condition, then they won’t work correctly.

2. How to adjust the desk alignment?

Leveling the deck height is very important to cut the grass more precisely. Uneven deck causes the blades to scalp the lawn by mowing too close. To balance the desk, first park it on a flat surface. Stabilize the mower and ensure the blades and moving parts have stopped.  After that, check the tires’ pressure and then measure the height of blades from the edge to the ground. If the difference between the peaks is more remarkable, then adjust it by lifting the link lock. Turn in clockwise to raise the mower and in an anti-clockwise direction to lower it. Adjust until the blade height difference is within 1/8 inches. Use a measuring tape to measure the heights. If the front blade tips are 1/8 inch to ½ inch lower than the rear blade tips, this is acceptable.

3. How much overlapping is needed while mowing?

An estimate of about 7 to 10 centimeters would be considered as a good overlap. Correct overlapping will ensure that your grass is being cut evenly. 

4. Do mower blades overlap?

Yes, the mower blades can overlap, but they do not overlap much. That’s why they are in a triangular pattern instead of in a straight line.

5. Should a mower deck be leveled?

For the most effective results, a lawnmower desk should be leveled. The height difference between the front and rear blades tip must be between 1/8 inch to ½ inch. It depends on the model of your lawnmower as well.

Final Remarks:

To conclude, we can say that everyone needs their lawnmower to work correctly and cut the grass evenly to make their back yards look more beautiful.  If the lawnmower is not cutting the grass evenly, then it can be frustrating. In this article, we have briefly explained the causes of the mower’s uneven cutting. If you face the same issues, and your mower is not cutting the grass more precisely, don’t get annoyed; go through the causes and follow the most comfortable solutions mentioned above. These tips and guidelines will help you fix your common mowing problems to keep your lawn looking the way you want it. Before servicing or repairing any power equipment, you must take good care of the safety precautions. Hopefully, these guidelines and tips will work correctly for you to solve your common mowing problems.

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