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Common Cub Cadet Mower Problems & Solutions

Owning a Cub Cadet lawn mower does not come without its problems. Even though Cub Cadet is a major player in the lawn care industry providing great products for your lawn needs, their lawn mowers will eventually fail. Whenever a product includes mechanical parts, it is bound to fail even if you take good care of it.

The most common problems in a Cub Cadet lawn mower are:

  • Cub Cadet fails to start
  • Cub Cadet loses power and dies
  • Cub Cadet begins smoking
  • Cub Cadet has a weak hydrostatic transmission
  • Cub Cadet won’t drive straight or steer correctly
  • Cub Cadet won’t move
  • Cub Cadet is vibrating
  • Cub Cadet is providing a bad or uneven cut

Many of these problems have simple solutions that you are able to do at home while some should be addressed by an experience lawn mower or small engine mechanic. I have listed causes with a quick solution. For more information on any issue, just follow the links provided.

Common Cub Cadet Problems

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Follow all safety instructions provided in your equipment operator’s manual prior to diagnosing, repairing or operating. Consult a professional if you don’t have the skills, knowledge or are not in the condition to perform the repair safely.

Cub Cadet Mower Problem 1: Mower Won’t Start

A Cub Cadet may not start because of a fuel or air restrictions not allowing the engine to get the fuel and air required to run. Your starting problem may also be due to a bad spark plug or a failed electrical component.

Detailed information can be found at:
Reasons a Cub Cadet Mower Won’t Start: The Complete List

CauseReason for ProblemSolution
No gas in the fuel tankFuel tank is EmptyFill with fresh fuel
Bad or old fuelFuel breaks down overtime making your fuel less efficient and prone to clogging the fuel systemDrain the fuel tank and fill with fresh fuel. Use a fuel additive like Sea Foam to stabilize the fuel and assist with cleaning the fuel system. Use the right fuel.
Faulty or clogged fuel capThe vent in the cap can get clogged causing your tank to form a vacuum restricting fuel flowUse a thin piece of wire to try to clear the clogged vent. Replace the cap if needed.
Bad spark plugExcessively dirty or broken spark plug; bad connection; not gapped correctlyReplace with a new spark plug, secure connections and ensure it is gapped to manufacturer specifications
Plugged air filterDirt and grass can plug the air filter preventing air flowRemove the filter and clean it. Replace the filter if it is in bad condition.
Plugged fuel filterA dirty fuel filter will restrict fuel flowReplace the fuel filter
Bad fuel pumpA failed or leaking fuel pump will no longer create pressure needed to pump fuelReplace the fuel pump
Blocked fuel linesBad fuel deposits and dirt can build up and clog the fuel lines preventing the engine from getting the required fuelUse a carb cleaner and compressed air to clear the clog out of the fuel line. Replace line if necessary.
Dirty carburetorThe carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flowClean all of the components making up the Cub Cadet carburetor. Replace if needed.
Bad battery or loose & dirty terminalsA dead battery, loose cables or corroded terminals can cause starting problemsCharge your battery and replace if it won’t hold a charge. Make sure your cables are tight and clean the corrosion from terminals.
Bad safety switchSafety switches is a safety measure that exist to prevent your mower from starting in certain situations. When a switch fails, your mower may not start.Test and replace faulty safety switch
Bad ignition switch or coilYour mower will not start when either the ignition switch or coil is badTest and replace a bad switch
Broken recoilA pull start mower may have a damaged or broke recoil preventing the recoil to initiate starting your engineCheck recoil to see if it can be restrung or broke parts, like the pulley, can be replaced. Replace the recoil assembly if needed.
Bad charging systemA charging system that isn’t able to keep your mower charged and is constantly draining the battery must be repaired to prevent starting problems.Take your lawn mower to your local Cub Cadet dealer for assistance identifying which part of the charging system has failed.
Why Your Cub Cadet Lawn Mower Won’t Start

Cub Cadet Mower Problem 2: Mower Loses Power and Dies

Cub Cadet lawn mowers can experience loss of power when the fuel or air systems are compromised affecting your mower’s ability to run. This can include bad fuel, a bad air filter, dirty carburetor, and clogged fuel lines.

Detailed information can be found at:
Cub Cadet Dies While Mowing

CauseReason for ProblemSolution
Bad fuelFuel breaks down overtime making your fuel less efficient and prone to clogging the fuel system and engine damageDrain the fuel tank and fill with fresh fuel. Use a fuel additive like Sea Foam to stabilize the fuel and assist with cleaning the fuel system
Plugged air filterDirt and grass can plug the air filter preventing air flowRemove the filter and clean it. Replace the filter if it is in bad condition.
Dirty or broken cooling finsCooling fins get packed with dirt, oil and grass not allowing air to effectively cool the engine blockReplace broken fins and clean the cooling fins.
Clogged fuel linesBad fuel deposits and dirt can build up and clog the fuel lines preventing the engine from getting the required fuel.Use a carb cleaner and compressed air to clear the clog out of the fuel line
Dirty carburetorThe carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flowClean all of the components making up the carburetor. Replace if needed.
Reasons Your Cub Cadet Mower Loses Power and Dies

Cub Cadet Mower Problem 3: Lawn Mower Smokes 

A Cub Cadet will smoke when oil gets into the cylinder and begins to burn off; components begin to burn due to increased friction from low oil capacity; and additional engine failures happen internally including the piston ring, valve train, and gaskets.

Detailed information can be found at:
Why Your Cub Cadet Lawn Mower is Smoking

CauseReason for ProblemSolution
Plugged air filterDirt and grass can plug the air filter preventing air flowRemove the filter and clean it. Replace the filter if it is in bad condition.
Too much oil in the crankcaseExcessive oil can cause pressure to build in the engine allowing oil to get into the cylinder through the valve trainDrain a little engine oil until it is at the manufacturers recommended oil level.
Low engine oil levelLack of oil can increase friction in your engine causing extreme heat in the engineBring to a small engine repair shop to inspect engine damage. You can try adding oil, but it is often too late to have this fix your engine problem.
Internal problems including the piston ring, valve train or engine gasketInternal engine problems can have a detrimental effect on your mower if they are not caught soon enough and fixed.Bring your Cub Cadet to your local small engine repair shop for troubleshooting
Why Your Cub Cadet Lawn Mower is Smoking

Cub Cadet Mower Problem 4: Weak Hydrostatic Transmission 

Cub Cadets that utilize a hydrostatic transmission may experience a weak transmission when the hydraulic is old or low in capacity. It can also feel weak when the drive belt or tensioner pulley is worn or broke.

CauseReason for ProblemSolution
Bad drive beltA bad drive belt can cause your pump not to work efficientlyReplace a frayed, cracked or worn belt
Bad tensioner pulleyWhen a tensioner pulley fails, it fails to keep tension on the drive beltReplace the pulley and grease the tensioner arm
Low or old hydraulic oilLow or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weakChange your hydraulic oil at regularly intervals as recommended by Cub Cadet.
Check your hydraulic oil periodically to ensure your hydraulic fluid is full.
Why Your Cub Cadet Hydrostatic Transmission Seems Weak

Cub Cadet Mower Problem 5: Mower Won’t Drive Straight or Steer Correctly

Several items can affect your Cub Cadet mower’s steering including incorrect tire pressures, bad dampers and worn steering components. The tracking may be off on Cub Cadet zero turns causing the mower to veer off to the right of left.

CauseReason for ProblemSolution
Incorrect tire pressureUnequal tire pressure can cause your mower to pull to one side.Check tire pressures and keep them filled to the manufacturers spec. Tires on each side of your mower requires equal pressures.
Bad dampers on zero turnBad dampers will cause your mower to jerk to one side when moving forwardReplace with a new damper
Tracking adjustment needed on zero turnWhen one tire is moving faster than the other, your mower can pull to one sideAdjust speed adjustment bolt to change the rotation speed of the tire. Refer to your owner’s manual.
Worn or loose steering components in riding mowerWorn bushings, washers and gears can cause your mower to not steer one way or the otherInspect and replace the parts that failed on your steering system
Why Your Cub Cadet Won’t Drive Straight or Steer Correctly

Cub Cadet Mower Problem 6: Lawn Mower Won’t Move

A Cub Cadet mower may not move due to a bad or missing drive belt, worn tensioner pulley, missing idler spring. The transmission bypass rod and the drive release lever may be in the wrong position on your Cub Cadet hydrostatic mower.

Detailed information can be found at:
9 Reasons Your Mower Won’t Move or Go Forward

CauseReason for ProblemSolution
Drive release lever or bypass rod is in the wrong positionThe drive release lever allows hydrostatic mowers to roll freely on a zero turn. A bypass rod can be found on a riding mower.The drive release lever must be in the operating position on a zero turn. The bypass rod must be disengaged.
Drive pump belt is wornThe mower won’t move if your drive belt has fallen off. It could also not move if the belt is worn.Replace a worn or cracked belt. Make sure the belt is securely around the pulleys.
Bad tensioner pulleyThe bearing in the tensioner pulley can failReplace the tensioner pulley
Missing idler arm springIf the idler arm spring breaks or goes missing, it can no longer place tension on the drive beltReplace the broken or missing spring
Low or old hydraulic oilLow or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weakChange your hydraulic oil at regularly intervals as recommended by Cub Cadet.
Check your hydraulic oil periodically to ensure your hydraulic fluid is full.
Hot hydraulic fluidHot hydraulic fluid can be a sign of damage to your hydrostatic transmission systemLet your hydraulic oil cool. If you find your mower runs fine when it is cold, but does becomes weak when the hydraulic system gets hot, have your mower checked at your local Cub Cadet dealership.
Air in the hydraulic systemAir must be bled from the hydraulic system after changing your hydraulic fluid or the mower will not be able to move at normal speedsFollow Cub Cadets procedures for changing hydraulic fluid and bleeding air from the system in your owner’s manual.
Reasons Your Cub Cadet Lawn Mower Won’t Move

Cub Cadet Mower Problem 7: Mower is Vibrating

A Cub Cadet may be vibrating because of loose components and hardware on the mower; failing components including bearings in the clutch, pulleys and spindle housings; damaged or unbalanced blades; and debris lodged under the pulleys and other areas of your Cub Cadet.

Detailed information can be found at:
How to Stop Your Lawn Mower from Shaking & Vibration

CauseReason for ProblemSolution
Loose or missing engine mounting boltsEngine bolts are used to reduce vibration of the mower when the engine is runningSecure engine bolts and replace any missing bolts
Failing clutchWhen there is bearing failure and it falls out of the clutch it can cause vibration. A manual engagement clutch can have a bushing and linkages that can fail.Replace the clutch
Unbalanced or damaged mower bladesBlades must be balanced before installing them on the mower. Vibration can be caused by unbalanced or damaged blades.Replace any damaged blades and make sure they are balanced.
Foreign material wrapped around the blade shaftForeign materials like string or long weeds can get wrapped around your blade shaft causing vibrationRemove all debris and items wrapped around the blade shaft. Check for spindle damage.
Bad spindle housing bearingsConfirm vibration is not coming from bad bearings in the spindle housing Replace bearing in the spindle housing or replace the whole spindle housing assembly
Bad deck belt or pulleysCheck deck belt and pulleys for wear and bearing failureReplace any damaged or worn belts and pulleys
Debris lodged in mowerStones, acorns, woodchips and other small items can get lodged in your mower under the pulleys or other items on your mower. Sometimes this causes your mower to shake.Check over your mower deck and mower for any place small items can be stuck in your mower. Remove these foreign materials.
Why Your Cub Cadet Mower is Vibrating

Cub Cadet Mower Problem 8: Mower Has a Bad or Uneven Cut

There are several items that can cause a Cub Cadet to provide a bad cut. Some of these items include a worn or damaged mower blade; uneven tire pressures; unleveled mower deck; slow engine speed; and a plugged mower deck.

Detailed information can be found at:
Why Your Cub Cadet Lawn Mower Cuts Uneven

Dull or worn mower bladeTire pressures unevenEngine speed is too low
Bent mower bladeMower deck is not levelGround speed is too fast
Blade installed wrongBlade spindle is bentDeck is damaged
Deck is plugged with dirtBad mower deck belt or pulleysOperator error
Reasons for a Bad or Uneven Cut from Your Cub Cadet Mower

My top items to keep on hand to service & troubleshoot your lawn mower

Socket & Allen Wrench Set – Tool set needed to service & troubleshoot your mower problemsCarburetor Cleaner – Clean clogs & buildup in fuel system
Multimeter – To check voltage, continuity & current to identify electrical problemsFuel Stabilizer – Stabilize & clean your fuel to minimize fuel system buildup
12-Volt Battery Charger – Battery/trickle charger to start your mower & slowly charge your batteryFilter Wrench – Helps loosen your filter
Oil Drain Pan – To collect oil with spout to place in containers for disposalBattery Powered Inflator – Keep your lawn mower tires inflated to prevent uneven cutting or steering issues