The Cub Cadet lawnmower is sputtering or running poorly

When the engine of a Cub Cadet lawn mower isn’t receiving enough air, fuel, or spark owing to a plugged air filter, jammed choke, obstructed fuel line, and obstructed fuel filter, filthy carburetor, defective gas cap, or dirty spark plug, the mower starts to run rough.

Additionally, a rapid ground speed, a low engine speed, a clogged mower deck, or worn mower blades may cause the engine to work too hard.

hile you wait for the engine to cool each moving component to cease moving before working on your lawn mower. Prior to making repairs, remove the spark plug wire and take the safety measures indicated in the Cub Cadet operator’s manual.


outdoor-cubPrior to diagnosing, repairing, or operating your equipment, make sure to follow all safety guidelines contained in the operator’s manual. If you don’t have the expertise, the abilities, or the health to safely complete the repair, consult a professional.

12 Reasons a Cub Cadet Lawn Mower Runs Rough & Bogs Down

Cub Cadet lawn mower with a plugged air filter

The air filter can become so clogged with dirt if you don’t periodically clean or substitute it to maintain its condition, making it impossible for enough air passing through.

A Cub Cadet engine with n obstructed air filter not only operate poorly, but it may also overheat.

The purpose of the air filter is to prevent dirt from being drawn into the air intake, which would otherwise cause engine wear. Make sure your mower is always running with an air filter installed, and include inspecting the filter in your pre-mowing check routine.

I advise cleaning the air filter frequently throughout the mowing season and changing it once a year. When operating the Cub Cadet in extremely dusty conditions, you might need to maintain or change the filter frequently.

Check the air filter’s condition and clean it if it’s a little dusty. Replace the filter with a new one if it is too unclean, broken, or no longer effectively seals the air intake. For your specific type of air filter, follow these cleaning instructions.

Cleaning the paper air filter on a Cub Cadet lawn mower

  • From the housing, remove the air filter.
  • Clear the housing of any leftover dirt. Don’t allow any dirt get into the air intake, please.
  • Tap the filter against something sturdy. The goal is to remove as much dirt from the filter as is likely to become loose and dislodge.
  • Check to check if ight is still visible pass by the use of paper of your air filter by holding it up to a source of light. Reusing your air filter is recommended whenever possible. It’s It’s time to replace it if you can’t.
  • our air filter housing cover to the housing after reinstalling the air filter.
  • Wash the filter with mild detergent and water if your air filter also employs a foam pre-filter. Rinse, then let the hair air dry. The pre-filter MUST NOT BE APPLIED WITH OIL.

Cleaning the foam air filter on a Cub Cadet lawn mower

  • From the housing, remove the air filter.
  • Clean out the filter housing of any debris. Make sure that no dirt gets into the air intake.
  • Check the filter. Replace your filter with a new one if you discover any black patches, tears, or if it is dry and brittle. Continue cleaning it If it seems to be in decent shape shape.
  • Use water and a mild detergent to clean your foam filter. Rinse the filter to get the soap out.
  • Dry by laying flat. Your filter will dry more quickly if you place it in the sun.
  • Apply foam air filter oil to the filter when it has completely dried. You want it to be completely covered in oil, but not dripping with it. If you accidentally get too much oil on the filter, ring it out or absorb it with a paper towel. (NOTE: Saturate a first-stage foam filter with oil. A foam pre-filter when paired with a paper air filter should never be oiled.
  • our air filter housing cover to the housing after reinstalling the air filter.

On a Cub Cadet lawn mower, a stuck or incorrect choke setting

ow much air is included into the mixture of air create engine combustion occurs here is limited by the usage of the choke. The amount of airflow required to fire up a frigid engine will decrease if the choke lever is in the choke position.

There must be a choke lever turned to the off settingonce the engine has started and warmed up in order to allow for the more air needed to keep the engine running.

The engine may start to run rough and bog down when the choke is set incorrectly or becomes either open or closed and stuck.

FIX: Make sure The choke lever is pulled all the way closed for cold starts and the open position for warm starts and running.

Check the choke plate to make sure hen the lever is adjusted, it opens and closes if the choke lever is in the proper position and you still experience airflow issues.

Replace a worn-out or dysfunctional choke cable and use a carburetor cleaning to release a stuck choke.

Old Gas in a Cub Cadet Lawn Mower

An old gas tank is frequently a blame for a Cub Cadet’s slow performance. This is due to the fact that gas starts to lose its effectiveness 30 days after purchasing.

Most gasoline is ethanol-based. Another plant-based fuel that draws moisture into the fuel system is this one. When he combination of ethanol and water evaporates, varnish and sticky residue are left behind.

imits on fuel and component problems may result from these clingy compounds.

Replace the old fuel in the fuel tank as a solution. To assist remove residue and moisture left behind by old gas, Include a fuel system and new gas cleaning and stabilizer like Sea Foam Motor Treatment.

Use gas with an octane rating of at least 87 and a maximum of 10% ethanol. The ideal gas is one without ethanol. Visit for further details on selecting the appropriate gas. The Cub Cadet lawn mowers use this kind of gas.

On a Cub Cadet lawn mower, the fuel line is clogged

Sticky buildup in the fuel system might get stuck in the fuel line and obstruct the flow of fuel. To stop and start, use the fuel shut-off valve or hose crimping pliers the flow of fuel while you inspect the stream leaving a line in order to locate a clogged fuel line.

As you monitor the fuel flow, gather fuel in a container. The fuel tank must be higher than this container. The usage of a gasoline pump is required for fuel to move uphill.

FIX: Cut off the fuel source and cut off the clogged fuel line. njecting line with carburetor cleaner might help to clear the obstruction.

After that, try to remove the blockage by blowing air pressure into the line until it is gone. ntil the obstruction is removed, keep applying compressed air and carburetor cleaner.

If ou can’t get rid of the gasoline restriction or notice that the fuel line is exhibiting signs of cracking, replace it with a fuel line that is the same length and diameter.

Cub Cadet lawn mower with a clogged fuel filter

In order to prevent dirt and debris from entering the fuel system, the majority of Cub Cadet lawn mowers have an inline fuel filter that is positioned in the middle of the fuel lines and strains the petrol as it leaves the fuel tank.

A good flow of fuel can’t pass through the fuel filter if it is clogged with dirt. The engine can bog down and run rough because the carburetor won’t get the fuel it needs.

To lessen the possibility of a blocked filter, the gasoline filter should be changed annually as part of routine maintenance.

A NEW INLINE FILTER SHOULD BE INSTALLED IN ITS PLACE OF THE OLD, UNCLEAN FILTER. ake certain the filter is mounted using the arrow pointing in the direction of the fuel flow by looking for an arrow on the new filter.

Dirty Carburetor on a Cub Cadet Lawn Mower

Gas and air must be mixed in the carburetor for combustion to occur in the engine. Because it isn’t receiving the proper gas and air combination when the carburetor isn’t operating as it should, the engine may operate poorly.

nsure you are receiving gasoline to the carburetor before attempting to isolate a fuel issue to the carburetor. nspect the gasoline line or fuel filter for obstructions if you are not.

If your Cub Cadet needs a fuel pump, make sure it is delivering fuel to the carburetor.

After that, take the air filter out of the housing. Allow the lawnmower to run after spraying cleaner for the carburetor into the air intake. It’s likely that the carburetor needs to be cleaned if the engine works smoothly for a while before becoming slow once more.

THE ANSWER: Clean the carburetor by following the step-by-step instructions in How to Clean Your Cub Cadet Lawn Mower Carburetor.

Bad Gas Cap on a Cub Cadet Lawn Mower

Air must be capable enter and exit the fuel tank so that it can escape. The gasoline tank vent on a Cub Cadet lawn mower is integrated into the gas cap.

To let air into the fuel tank oosen the gasoline cap if the engine is making loud noises. If the engine starts to run more smoothly, you might have a faulty gas cap that isn’t venting correctly.

Retighten the gas cap and let the mower continue to run to verify the issue. Open the cap and listen to the engine when it starts to run slowly. Again, the gas cap is probably the issue if the vehicle no longer bogs down and runs rough after you loosen the cap.

FIX: Get a fresh gas cap for your Cub Cadet and put it on.

Spark plug on a Cub Cadet lawn mower that is dirty

When the spark plug is unclean, the Cub Cadet mower may only spark sometimes. The engine may then run rough as a result. Other factors that contribute to intermittent spark problems include an improperly adjusted electrode gap and a loose spark plug wire.

SOLUTION: Take out the spark plug and examine it. Replace it with a new one if you discover that it is extremely black in color, has a burned electrode, or is otherwise damaged.

Check to see if the spark plug is gapped according to the engine manufacturer’s requirements. Connect the spark plug wire firmly.

Ground Speed is Too Fast with a Cub Cadet Lawn Mower

The pace you should mow at depends on the conditions. Mowing must be done at a slower rate on a lawn with thick, tall, or damp grass than on a dry lawn with short, fine grass.

The engine will be put under more stress and may bog down if you mow at a ground speed that is too high for the circumstances you are mowing in. You’ll also get a subpar cut as a result.

ASSESS THE MOWING CONDITIONS, THEN CHANGE YOUR GROUND SPEED. When you see that your engine is sputtering and not running well, slow down.

The best strategy for cutting tall grass is to use several passes. Although it will take much longer, the cutting results will be superior and the engine won’t be overworked. You can accomplish this by initially setting your mower’s cutting height to its highest setting, and then lowering it for successive cuts.

Engine Speed on a Cub Cadet Lawn Mower is Too Low

A Cub Cadet mower and mower deck require a lot of engine power to operate. When engaging the blades, the engine speed should be at its highest setting to prevent the mower from running erratically.

The throttle lever should be set to the highest engine speed. This is denoted on many lawnmowers with a rabbit icon.

Plugged Mower Deck on a Cub Cadet Lawn Mower

The engine will have to work harder to turn the blades through a mower deck that is clogged with grass clippings and debris.

The engine will be strained and sluggish as a result of having to turn the blades through this extra material.

SOLUTION: To keep the mower deck clean, use a wire brush or deck scraper. Do not cut damp or wet grass. This grass has a higher propensity to cluster and adhere to the deck.

If you want to prevent debris from sticking, you might try using a deck spray. Although it does assist, it is not a foolproof method to prevent all grass from adhering to the deck.

Cub Cadet lawn mower with dull blades

A beautiful cut can be achieved using sharp mower blades. Due to bruising, dull mower blades may shred the grass, leaving it with brown tips a few days after mowing.

In addition to having a bad cut, dull mower blades can make a blocked lawn mower deck worse. As a result, the engine would bog down even more because it requires more effort to turn dull blades through a deck full of grass.

FIX: Take the mower blades out of the deck. As stated in Change & Sharpen Your Cub Cadet Mower Blades, sharpen and balance the blade.

Having Issues With Your Cub Cadet Mower Right Now?

Check out my page detailing the most typical Cub Cadet problems and their remedies if these suggestions haven’t resolved your Cub Cadet issue or if you are having another issue with your Cub Cadet: Typical Cub Cadet Issues

You can uncover the root causes of Cub Cadet problems like a mower that won’t start, a lousy cut, vibration, or smoking here. I provide answers as well as references to further reading.