6 Reasons Why Is My 3 Blade Mower Cutting Unevenly? (How to Fix)

3 Blade mower features higher speed & broader cutting area to deliver faster even cuts.

But what if your 3 blade mower cutting uneven?

Since various reasons can drive you to experience this, start the investigation by checking the current condition of the front & rear tires, deck, and blades to diagnose & find out the main culprit. Take the necessary actions.

However, the entire process is relatively convenient and easy, so continue reading this article to learn how to do that.

6 Reasons Why Your 3 Blade Mower Cutting Uneven?

The most common reasons are:

  1. Insufficient or improperly Inflated Tires
  2. Incorrect leveling of the Deck
  3. Built-up Junk underneath the Mower Deck
  4. Too Fast/Slow Ground Speed
  5. Any issues with the Blades
  6. Misjudged Overlapping

How to Diagnose & Fix Your 3 Blade Mower? (6 Easy Ways)

Here are the top 6 things that you should immediately check on and perform required fixing techniques to prevent your mower from delivering uneven cuts.

1. Insufficient or Improperly Inflated Tires: 

Deflated front & rear mower tires will reduce the traction as well as restrict the deck and blades from floating evenly.

Such a situation can eventually shorten the tire’s life.

Therefore, check and make sure you have at least 12-13 lbs. of air pressure in each tire of your 3-blade mower.


Bring a standard pressure gauge and check on any of the tire’s sidewall to find out the correct recommended tire pressure for your mower.

Then locate the tire valve on one of your mower tires.

If you see that the cap is missing/damaged, add a new one after ensuring that both tires have proper air pressure.

Place the pressure gauge on that valve and press down so that it can release some air. Similarly, check the air pressure rate on the other tire.

If the pressure gauge monitor shows results below the recommended PSI on any or both tires, refill the tires until you get the recommended pressure on both tires.

2. Incorrect Leveling of the Deck:

If the 3-blade deck on your mower is not leveled or balanced accurately, you will surely witness rough and uneven cuts on your lawn.

So, check the leveling condition of your mower deck and if necessary, level the deck once again.

Things You Will Need:

A Wrench Set
A Ruler
Tire Pressure Gauge
Air Supply


Park your mower on a level surface and set the brake on the parking. Raise the deck to its highest position and disengage the cutting blades.

Shut off the engine and take the ignition key off.

Inflate the front & rear tires to their recommended pressure.

Be sure that both tires have equal pressure on them.

Ensure that the blades are parallel with the mower before measuring the distance from the front tip of the blade to the ground.

Similarly, measure the distance from the back tip of the blade to the ground.

If the measurement does not show that the front tip is a quarter of an inch or a 3/8 an inch lower than the back tip, you need to perform the adjustment.

Adjust the height by adjusting the middle lock nut accordingly.

Then, measure the non-suit side, and if the measurement is not within 1/8 to ½ of an inch and so level the deck from side to side.

3. Built-up Junk Underneath the Mower Deck:

When an excess amount of debris or impacted clippings is built up underneath the mower deck, it can restrict the airflow and internal operations leading your 3 blade mower cutting uneven.

Mowing very wet or high grass mainly causes impacted clippings to built-up like that.

So, inspect and clean the inside of your regularly used mower deck frequently to avoid such a commotion.


Go underneath your mower deck and check whether it’s too dirty or covered with junk.

If it is, you should take a wooden stir, window scrapers putty knife, or a flathead screwdriver and clean the inside of your deck.

4. Too Fast/Slow Ground Speed: 

Your mower will fail to deliver expected even cuts if the ground speed is too high because, in that case, your mower won’t get enough time to trim effectively and make all the grass look evenly cut.

Even too slow ground speed will damage the grass during mowing since the blades won’t have enough power to run faster to trim them smoothly.


If the ground speed is set too fast or high, use the transmission of your mower and select a slower ground speed to experiment until you find the optimal speed needed to get even cuts.

Note: Remember, your mower blades should run at full throttle to have enough power to deliver smooth even cuts.

Similarly, if the ground speed seems too slow, adjust the RPM to the required RPM and make sure that the blades are spinning at least 3000 RPM.

But for a better result set your mower engine to 3400-3600 RPM.

Related Post: Can You Put a Bigger Deck on Your Mower? (What Experts Say?)

5. Any Issues with the Blades: 

If mower blades are not fastened securely and when one or more blades come loose from their connection, your mower won’t cut smoothly and will eventually damage the grass of your lawn.

A similar situation can also occur if the blades become too dirty or have turned bent due to hitting a rock.


Tilt the mower to get access to the blades to check whether there’s any loose connection or the blades have turned dirty.

If blades are covered with built-up dirt, clean the blades.

If you notice a loose connection, grab the blade and position the socket over the securing bolt.

Take a screwdriver or torque wrench and tighten the bolt until you hear a click.

Repeat the process on the other side of the mower.

Take the deck off to check whether one or multiple blades by spinning the mower blades one by one.

If they look parallel, that means they are good to go.

But if any of them looks slightly bent, use a hammer to fix the bent side of that blade or replace the damaged blade.

Related Post: 52 Vs 60 Inch Deck: Which Is Better for Lawn or Yard Care?

6. Misjudged Overlapping: 

Often beginners misjudge their overlapping, which causes uneven cuts in between rows during mowing.

If you miss any of the rows while passing, it will result in uneven or incomplete mowing.


If you are new to these mowers, check the manual thoroughly to know how to calculate all the passes and mow the grass in perfect sync.

Another way is to get off your mower in between a few passes to ensure you are not missing any rows in between and confirm that your mower is cutting them evenly.

Frequently Asked Questions (FAQs):

Which mower blade do most professionals use?

Most professionals prefer & use Gator blades for mowing.

How often should I clean the blades on my 3 blade mower? 

At least twice a week.

Which pattern should I follow to mow my lawn with a 3 Blade mower?

The easiest way is to finish mowing the edges properly and then, take passes with your mower in a circular pattern until you reach the middle.

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