12 Causes of a Rough or Stuttering Kubota Lawnmower

Inevitably, the motor on your riding mower or zero-turn mower will start to splutter and lose power.

When the engine isn’t getting enough air, fuel, or spark, as could happen if the air filter is blocked, the throttle is jammed, the fuel line is clogged, the fuel filter is clogged, the carburetor is dirty, the gas cap isn’t sealing properly, or the spark plug is dirty on a Kubota lawn mower.

Causes include operating at too high of a ground speed, too low of an engine speed, a clogged mower deck, or dull mower blades.

Wait until the engine has cooled and all the moving parts have stopped before attempting any maintenance on the lawn mower. The spark plug wire must be disconnected before any maintenance may be performed, and all other safety measures outlined in the Kubota manual must be observed.

12 Causes of a Rough or Stuttering Kubota Lawnmower

This Is Why Your Kubota Lawnmower Is So Rough and Slow

A Kubota Lawnmower With a Clogged Air Filter

The purpose of an air filter is to prevent damaging debris from entering the engine’s air intake system. It’s vital that you keep it tidy and in good shape at all times.

If you don’t clean or replace the filter on a regular basis, it might get clogged with dirt and debris, preventing enough air from reaching the engine.

The engine may overheat or perform poorly as a result of this.

The air filter should be changed annually and cleaned multiple times during the mowing season. When operating the Kubota in extremely dusty conditions, or if you use your mower more frequently than the typical homeowner, you may need to cleanse or substitute the filter more frequently.

SOLUTION: If the air filter appears to be slightly soiled, clean it. An air filter should be swapped out when it becomes too dirty, is damaged, or fails to properly seal off the air intake. To clean the air filter you have, please refer to the guidelines below.

How to clean the paper air filter in a Kubota lawn mower:

  • Take off the air filter and put it in a separate container.
  • Clean up any lingering grime within the case. Avoid getting any dust or dirt in the air filter.
  • Strike the filter against something substantial. The goal is to loosen and dislodge as much dirt from the filter as possible.
  • Make that the air filter can still allow light to pass through by holding it up to a bright light. If the air filter is in good condition, you can reuse it. If you can’t fix it, then it’s time to replace it.
  • Simply replace the air filter and snap on the housing cover again.
  • If your air purifier has a foam pre-filter, you can clean it with little water and a light detergent. Simply rinse and hang to dry. The pre-filter should not be oiled.

A Kubota Lawnmower With a Stuck Choke or an Incorrectly Set Choke

To lessen the volume of air added to the mixture during combustion, the choke can be used. Restricting airflow by moving the choke lever into the choke position makes it more challenging to start a cold engine.

The choke lever must be switched to the “off” position once the engine has been started and warmed up so that it may receive the additional air it requires to continue running.

If the choke is in the wrong position, or if it gets stuck in the open or closed position, the engine may start running coarsely and finally bog down.

Before trying to start the engine from cold, make sure the choke lever is all the way closed. If you want to start and run the engine while it’s warm, you need to make sure the choke lever is in the open position.

When adjusting the choke lever, double-check that the choke plate opens and shuts smoothly. If you’re having trouble breathing, doing this is a good idea even if the choke lever is set properly.

If the choke is stuck, use carburetor cleaner to free it, and if the choke cable is old and no longer functional, replace it.

The Use of Outdated Fuel in a Kubota Lawnmower

A month after purchasing, gas already begins to degrade. Nowadays, most gasoline on the market has ethanol added to it. This is a renewable energy source refined from plants.

Over time, ethanol and the water it absorbs settle to the bottom of the fuel tank, where they are no longer mixed with the gas. Not only does this mixture leave behind sticky deposits, but it is also very corrosive and can harm fuel components.

As a result of these fuel constraints, the engine will not receive the fuel it needs to operate efficiently.

SOLUTION: Drain and substitute the fuel in the tank. To get rid of the muck and grime that the old gas left behind, put in some new gasoline and a fuel system cleaning and stabilizer like Sea Foam Motor Treatment.

Fuel with an octane rating of 87 or above and no more than 10% ethanol should be used. The finest gas is one without ethanol. Check read This Is the Gas Used by Kubota Lawn Mowers for more details on fueling your mower.

Kubota Lawnmower Fuel Line Plugged

Debris from the fuel system might clog the fuel line and cause the engine to sputter. A clogged fuel line can be located by temporarily halting gasoline flow through the line using the fuel shut-off valve or hose crimp pliers and then restarting it.

Check the fuel flow when collecting petrol in a container. This storage unit must be situated below the gas tank. Without a gasoline pump, fuel will not flow uphill.

The answer is to disconnect the clogged fuel line and turn off the gasoline supply. Use carburetor cleaning to spray into the pipe in an effort to break up the clog.

The next step is to try to clear the blockage by blowing compressed air into the line. Carburetor cleaning and compressed air should be used repeatedly until the obstruction is removed.

In the event that you are not able to remove the fuel restriction or if you discover fractures in the fuel line, you should replace it with one of the same length and diameter.

A Kubota Lawnmower’s Fuel Filter Is Clogged

The mower’s fuel system and engine are protected by an inline fuel filter in the event of a fuel contamination. The fuel filter, like the air filter, needs to be regularly replaced to ensure the fuel is clean.

When the gasoline filter gets clogged with grime, the fuel flow is restricted. If fuel isn’t getting to the carburetor, the engine may sputter and stumble.

When the fuel filter becomes clogged or broken, it should be changed more frequently than once a year.

The problem can be fixed by replacing the old, clogged filter with a new in-line filter. Make sure the new filter’s arrow points in the direction of gasoline flow by checking for it and installing it accordingly.

A Kubota Lawn Mower with a Filthy Carburetor

The carburetor is the part of the engine that combines fuel and air to produce combustion. The engine may have a rough idle or operate poorly if the carburetor is not delivering the proper gas and air mixture.

First, verify that fuel is reaching the carburetor before diagnosing it as the source of the problem. If you aren’t, perhaps your gasoline line is clogged, your fuel filter is dirty, or your fuel pump is broken.

Get the air filter out of its housing next. Just spray some carburetor cleaning into the air intake and start the mower up.

If your engine performs fine at first, but then starts to sputter, it’s probably time to clean the carburetor.

A Kubota Lawnmower with a Leaking Gas Cap

There must be a way for air to enter and exit the gasoline tank. The gas cap on a Kubota lawnmower doubles as an exhaust port for the machine’s fuel tank.

A vacuum will build preventing fuel from escaping the tank if the gas cap vent is blocked.

If your engine is stuttering for no apparent reason, try releasing some air from the fuel cap. One possible cause of an improved engine’s performance is a faulty gas cap that is no longer venting.

To verify the issue, try running the mower again with a freshly tightened gas cap. When it slows down, have a listen with the cap off. Once again, the gas cap is probably the culprit if the vehicle no longer has the same rough and sluggish performance after being started with the cap loosened.

Get a new gas cap for your Kubota and put it on.

A Kubota Lawnmower with a Dirty Spark Plug

If the spark plug in your Kubota mower is unclean, you may suffer erratic ignition. This can cause the car to have a shaky engine. Intermittent spark problems can also be caused by an electrode gap that isn’t properly set or a spark plug wire that isn’t securely fastened.

Take out the spark plug and check it out. You should get a replacement one if you see that it has turned a very dark color, has a burnt electrode, or is otherwise damaged.

Make that the space between the spark plug’s electrodes is as specified by the engine’s manufacturer. After any necessary repairs are done, the spark plug wire should be reattached securely.

The Ground Speed of a Kubota Lawnmower Is Too High

How fast you should mow is determined by the weather and the terrain. When mowing a lawn, it’s important to go slower if the grass is particularly thick, tall, or wet than if it’s dry and not particularly tall or thick.

If you’re mowing in conditions when a slower ground speed would be more appropriate, you’re putting unnecessary stress on the mower’s motor. Also, you can expect a subpar cut from using it.

ANSWER: Take a look at the lawn and see how fast you’re going and slow down if necessary. When you notice that your car’s engine is losing power, it’s time to slow down.

Mowing tall grass requires numerous passes. Cutting will be more effective, but the process will take much longer because the engine won’t be stressed as much.

You can accomplish this by increasing the cutting height of your mower for the initial cut and then decreasing it for subsequent cuts.

The Engine Speed on a Kubota Lawn Mower is Way Too Slow

Operating a Kubota mower and mowing deck requires a sizable engine. If the mower starts to operate roughly, increase the engine speed to its maximum before engaging the blades.

The ANSWER is to raise the accelerator pedal to its highest setting. Some mowers include a bunny symbol to indicate this.

Kubota Lawnmower Deck Won’t Unplug

If the mower deck is clogged with dead grass and other debris, the engine will have to work harder to spin the blades.

The engine will struggle to turn the blades through all of this extra weight, and as a result, performance will suffer.

To solve this problem, you can use a deck scraper or wire brush to regularly clean the mower deck. It’s best to wait until the grass is dry before cutting it. This type of grass is more likely to form clumps and stay adhered to the patio.

The application of a deck spray may be useful in preventing debris from clinging to the surface. In spite of its usefulness, it is not a foolproof method of preventing grass from permanently adhering to the deck.

Kubota Lawnmower with Dull Blades

Maintaining razor-sharp mower blades is essential for producing clean cuts. Mowing with dull blades can shred the grass, causing the tips to darken a few days later as a result of trauma.

Dull mower blades not only make for an unsightly cut, but can also make it more difficult to unclog the deck of a lawn mower. Because it takes more power to spin dull blades through a deck full of grass, this will exacerbate the problem.

The problem can be fixed by taking the mower’s blades off the deck. Follow the steps outlined in Change & Sharpen Your Kubota Mower Blades to restore the blade’s cutting edge and balance.

Still having issues with your Kubota lawnmower?

When you’ve had a lawnmower for a while, it’s bound to develop some sort of trouble, whether it won’t start, won’t stay running, smokes, leaks gas, cuts poorly, vibrates, or something else entirely.

Save yourself some time and money by using this tutorial the next time your Kubota mower gives you difficulties.

Fixing your Kubota lawnmower is easy with this information, which you can find at Common Kubota Lawn Mower Problems & Solutions.

Hire a professional to fix your Kubota lawnmower if you don’t feel confident diagnosing and fixing it yourself.

You’ll save yourself from harm and the mower from further destruction by doing this. If you are having trouble with your lawn mower, head on over to the nearest Kubota dealer or lawn mower repair business.