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 experienced 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.
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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, or 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 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
| Cause | Reason for Problem | Solution |
|---|---|---|
| No gas in the fuel tank | Fuel tank is Empty | Fill with fresh fuel |
| Bad or old fuel | Fuel breaks down overtime making your fuel less efficient and prone to clogging the fuel system | Drain the fuel tank and fill it 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 cap | The vent in the cap can get clogged causing your tank to form a vacuum restricting fuel flow | Use a thin piece of wire to try to clear the clogged vent. Replace the cap if needed. |
| Bad spark plug | Excessively dirty or broken spark plug; bad connection; not gapped correctly | Replace with a new spark plug, secure connections, and ensure it is gapped to manufacturer specifications |
| Plugged air filter | Dirt and grass can plug the air filter preventing airflow | Remove the filter and clean it. Replace the filter if it is in bad condition. |
| Plugged fuel filter | A dirty fuel filter will restrict fuel flow | Replace the fuel filter |
| Bad fuel pump | A failed or leaking fuel pump will no longer create the pressure needed to pump fuel | Replace the fuel pump |
| Blocked fuel lines | Bad 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. Replace the line if necessary. |
| Dirty carburetor | The carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flow | Clean all of the components making up the Cub Cadet carburetor. Replace if needed. |
| Bad battery or loose & dirty terminals | A dead battery, loose cables, or corroded terminals can cause starting problems | Charge your battery and replace it if it won’t hold a charge. Make sure your cables are tight and clean the corrosion from terminals. |
| Bad safety switch | Safety switches are a safety measure that exists 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 coil | Your mower will not start when either the ignition switch or coil is bad | Test and replace a bad switch |
| Broken recoil | A pull start mower may have a damaged or broken recoil preventing the recoil to initiate starting your engine | Check the recoil to see if it can be restrung or if broken parts, like the pulley, can be replaced. Replace the recoil assembly if needed. |
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, a dirty carburetor, and clogged fuel lines.
Detailed information can be found at:
Cub Cadet Dies While Mowing
| Cause | Reason for Problem | Solution |
|---|---|---|
| Bad fuel | Fuel breaks down overtime making your fuel less efficient and prone to clogging the fuel system and engine damage | Drain the fuel tank and fill it with fresh fuel. Use a fuel additive like Sea Foam to stabilize the fuel and assist with cleaning the fuel system |
| Plugged air filter | Dirt and grass can plug the air filter preventing airflow | Remove the filter and clean it. Replace the filter if it is in bad condition. |
| Dirty or broken cooling fins | Cooling fins get packed with dirt, oil, and grass not allowing air to effectively cool the engine block | Replace broken fins and clean the cooling fins. |
| Clogged fuel lines | Bad 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 carburetor | The carburetor can become dirty and clogged due to bad fuel and ethanol deposits preventing fuel flow | Clean all of the components making up the carburetor. Replace if needed. |
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
| Cause | Reason for Problem | Solution |
|---|---|---|
| Plugged air filter | Dirt and grass can plug the air filter preventing airflow | Remove the filter and clean it. Replace the filter if it is in bad condition. |
| Too much oil in the crankcase | Excessive oil can cause pressure to build in the engine allowing oil to get into the cylinder through the valve train | Drain a little engine oil until it is at the manufacturer’s recommended oil level. |
| Low engine oil level | Lack of oil can increase friction in your engine causing extreme heat in the engine | Bring to a small engine repair shop to inspect engine damage. You can try adding oil, but it is often too late to this fix your engine problem. |
| Internal problems including the piston ring, valve train, or engine gasket | Internal 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 |
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.
| Cause | Reason for Problem | Solution |
|---|---|---|
| Bad drive belt | A bad drive belt can cause your pump not to work efficiently | Replace a frayed, cracked, or worn belt |
| Bad tensioner pulley | When a tensioner pulley fails, it fails to keep tension on the drive belt | Replace the pulley and grease the tensioner arm |
| Low or old hydraulic oil | Low or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weak | Change your hydraulic oil at regular intervals as recommended by Cub Cadet. Check your hydraulic oil periodically to ensure your hydraulic fluid is full. |
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.
| Cause | Reason for Problem | Solution |
|---|---|---|
| Incorrect tire pressure | Unequal tire pressure can cause your mower to pull to one side. | Check tire pressures and keep them filled to the manufacturer’s spec. Tires on each side of your mower require equal pressure. |
| Bad dampers on zero turn | Bad dampers will cause your mower to jerk to one side when moving forward | Replace with a new damper |
| Tracking adjustment needed on zero turn | When one tire is moving faster than the other, your mower can pull to one side | Adjust the speed adjustment bolt to change the rotation speed of the tire. Refer to your owner’s manual. |
| Worn or loose steering components in riding mower | Worn bushings, washers, and gears can cause your mower to not steer one way or the other | Inspect and replace the parts that failed on your steering system |
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, or 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:
Why Your Cub Cadet Lawn Mower Won’t Move or Go Forward
| Cause | Reason for Problem | Solution |
|---|---|---|
| Drive release lever or bypass rod is in the wrong position | The 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 worn | The 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 pulley | The bearing in the tensioner pulley can fail | Replace the tensioner pulley |
| Missing idler arm spring | If the idler arm spring breaks or goes missing, it can no longer place tension on the drive belt | Replace the broken or missing spring |
| Low or old hydraulic oil | Low or old hydraulic oil can fail to lubricate the hydraulic system causing your hydraulic system to seem weak | Change your hydraulic oil at regular intervals as recommended by Cub Cadet. Check your hydraulic oil periodically to ensure your hydraulic fluid is full. |
| Hot hydraulic fluid | Hot hydraulic fluid can be a sign of damage to your hydrostatic transmission system | Let your hydraulic oil cool. If you find your mower runs fine when it is cold, but becomes weak when the hydraulic system gets hot, have your mower checked at your local Cub Cadet dealership. |
| Air in the hydraulic system | Air must be bled from the hydraulic system after changing your hydraulic fluid or the mower will not be able to move at normal speeds | Follow Cub Cadet’s procedures for changing the hydraulic fluid and bleeding air from the system in your owner’s manual. |
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:
Reasons Your Cub Cadet Mower is Vibrating
| Cause | Reason for Problem | Solution |
|---|---|---|
| Loose or missing engine mounting bolts | Engine bolts are used to reduce the vibration of the mower when the engine is running | Secure engine bolts and replace any missing bolts |
| Failing clutch | When 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 blades | Blades 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 shaft | Foreign materials like string or long weeds can get wrapped around your blade shaft causing vibration | Remove all debris and items wrapped around the blade shaft. Check for spindle damage. |
| Bad spindle housing bearings | Confirm vibration is not coming from bad bearings in the spindle housing | Replace the bearing in the spindle housing or replace the whole spindle housing assembly |
| Bad deck belt or pulleys | Check deck belt and pulleys for wear and bearing failure | Replace any damaged or worn belts and pulleys |
| Debris lodged in mower | Stones, acorns, woodchips, and other small items can get lodged in the 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. |
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; an 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 blade | Tire pressures uneven | Engine speed is too low |
| Bent mower blade | Mower deck is not level | Ground speed is too fast |
| Blade installed wrong | Blade spindle is bent | Deck is damaged |
| Deck is plugged with dirt | Bad mower deck belt or pulleys | Operator error |