13 Cub Cadet Zero Turn Mower Troubleshooting

It’s certain that if you keep a Cub Cadet zero-turn mower for any length of time, it will develop some sort of malfunction that will require servicing. In fact, this is true for every item with a mechanical working mechanism. Sooner or later, they’re going to break down and wear out.

Preventing corrosion on a lawnmower is as simple as keeping it clean and putting it away somewhere dry. Keeping up with regular maintenance and utilizing premium gas will help keep your Cub Cadet zero-turn running well for years to come.

I have compiled this checklist to assist you in diagnosing the source of your mower’s malfunction. You can also discover links to articles that provide even more context for the information presented in the charts.

If you want to avoid getting hurt when fixing your Cub Cadet, make sure to follow all of the guidelines outlined in the owner’s manual. Whenever you need to make repairs to your lawnmower, you should always do so on a flat, level surface, with the ignition key out of the ignition and the spark plug wire disconnected.

Listed below are the 13 most frequently reported issues with Cub Cadet zero-turn mowers:

cub cadet mower


Issue 1: Mower Won’t Start

If the engine doesn’t obtain the oxygen, gasoline, and spark it needs to generate an explosion, your Cub Cadet zero-turn won’t start. It’s not just the starter that can go bad; the battery, solenoid, and switches can all play a role in preventing the engine from turning over.

Possible Reasons

Empty fuel tankFill with fresh fuel.
Outdated fuelTake the gas out of the car. Replenish the tank with new gas and a fuel system cleaner such as Sea Foam.
Bad spark plugSpark plugs should be changed whenever they become dusty or worn.
Air filter clogThe air filter needed cleaning. A broken or extremely dirty filter should be changed.
Fuel filter cloggedGet a new fuel filter.
Fuel line clogA clogged gasoline line must be removed and cleaned. If the line is broken, please replace it.
Fuel pump failureSubstitute a gasoline pump that isn’t working.
Clogged carburetorIt is necessary to take out the carburetor and clean it. If it’s broken, fix it or get a new one.
A faulty battery, frayed wires, or corroded terminalsRejuvenate a low battery. If your battery isn’t holding a charge, you should get a new one. Anchor wires and scrape away corrosion from hardware.
A faulty safety switchIf there is a faulty safety switch, please replace it.
Faulty ignition switchThe faulty ignition switch must be replaced.
Faulty starter solenoidReplace a failing solenoid starter after testing it.

Issue 2: Mower Begins the Dies

The same issues that prevent a zero-turn mower from starting are often to blame for its premature demise. Furthermore, you should examine the engine oil level, the ignition coil, and any obstructions in the mower deck.

Possible ReasonsOption
Outdated fuelEmpty out the gas tank. New gas can be stabilized, moisture can be removed, and the fuel system can be cleaned by adding a fuel additive. Increase the amount of fuel in the tank.
Plugged air filterThe air filter needed cleaning. If the filter is damaged or excessively unclean, you should replace it.
Dirty cooling finsRemove any debris from surrounding the cooling fins, and swap out any that are damaged.
Clogged fuel linePull out the gasoline line and try to clear out the obstruction. If you are unable to unblock the gasoline line, you will need to replace it.
Bad fuel pumpWhen the fuel pump stops working, you need to replace it.
Dirty carburetorIf the carburetor is clogged, you must take it apart and clean it. If the carburetor can’t be cleaned well or if internal parts are broken, you should either rebuild it or replace it.
Bad fuel cap / fuel tank ventIf the fuel tank can’t vent through the cap, you need to substitute the cap.
Wrong engine oil levelTo adjust the oil level in the engine, add or drain a small amount until the oil reaches the level specified by the engine manufacturer. If this does not resolve the issue, you should contact a mechanic. There could be serious engine damage on the zero-turn.
Plugged mower deckRemove grass from the mower’s deck. The mower’s blades need sharpening.
Bad ignition coilFix the continuity problem by getting a new ignition coil.
Dirty spark plugWhen a spark plug loses its original color, becomes damaged, or shows signs of wear and tear, it should be replaced. If they are still in decent shape but have picked up a little layer of grime, scrub them with a wire brush.

Issue 3: It Neither Goes Forward Nor Backward

Hydrostatic transmission works by pumping fluid to the wheels, which causes them to turn. As a result of the intense strain, free-rolling the zero turn will require disabling the transmission.

Verify that the gear selector levers are not in the “bypass” position. Make that the tensioners, pulleys, and belt are all in good working order. Check that the oil level is full and that it is fresh.

Possible ReasonsOption
The improper placement of the transmission’s bypass leversAdjust the transmission’s bypass levers to “run.” The drive wheels each have a lever next to them.
Belt for drive pump is wornIf the belt is frayed or not sitting flush on the pulleys, replace it.
The tensioner pulley is faulty.Simply switching out the pulley tensioner. Coat the tensioner arm in grease.
Lacking or broken idler arm springThe spring must be replaced if it is broken or missing.
Inadequate or stale hydraulic oilFollow Cub Cadet’s suggested maintenance schedule for changing the hydraulic oil.
Hydraulic fluid levels should be checked on a regular basis to ensure that there is enough oil.

Issue 4: The Lawnmower Vibrates

When mowing the lawn, even with a seat suspension system, you’ll still experience some bouncing and jolting. The shakiness and bouncing may become more severe if you get a vibration.

Examine the engine mounting bolts and the clutch for signs of wear. Verify that all of the mower’s links are in working order, and clear it of any debris. Pulleys and blades can wobble and the deck belt can come loose if the mower deck’s components break or wear out.

Mounting bolts for the engine are either loose or absent.Put the engine mount bolts in a safe place. Fix or replace any bolts that are loose or missing.
Failing clutchIt’s time to get a new electric clutch. Fix a clutch that requires human engagement by replacing its worn cable, lever, or bushings.
Mower blades that aren’t in good shapeRemoved and replaced the worn-out cutting edge. Verify that they are well-balanced.
The blade shaft has foreign objects wrapped around it.Take out the foreign object snagged on the blade’s shaft. It’s important to check the spindle and the housing for any signs of wear and tear.
Faulty bearings in the spindle housing.Spindle bearings should be inspected regularly and replaced if they show signs of wear.
Bad deck beltDeck belt replacement is required.
Bad pulleysIn the event that any of your pulleys are damaged, or if you experience any resistance when turning them by hand, or if they wobble because of a poor bearing, you should replace them immediately.
The mower was clogged with debris.Take the time to clean the mower thoroughly, including the undercarriage.

Issue 5: Overheating of Your Cub Cadet Zero-Turn Mower

The engine oil helps to maintain the engine’s temperature. Oils rich in zinc are recommended for air-cooled engines. Make sure the oil level in the car’s engine never drops below the minimum required level.

The cooling fins, the engine shroud, and the engine guard are all potential airflow obstructions that should be checked.

You should check the quality of the air filter, the mower deck, and the blades.

Possible ReasonsOption
Wrong engine oilIt’s time to change the oil in the car’s engine, so drain it and replace it. Oils with SAE30 or 10W-30 ratings should be used under most circumstances. When temperatures rise dramatically, you may need to switch to a different viscosity.
Low engine oil levelEmpty out the gas tank. Gasoline containing an additive to help clean the fuel system and keep it stable should be used to refill the tank.
Plugged engine cooling finsCleaning the carburetor requires its removal.
MIssing engine guardReplacing the missing guard. A dangling guard must be fastened securely.
Plugged air filterSubstitute a dirty air filter.
Plugged mower deckGrass clippings and other debris can be removed by scraping the mower deck.
Dull mower bladesFix mowers with dull blades by sharpening them. Blades should be replaced when they become dull.
Overworking the engine
Reduce the ground speed to a level appropriate for mowing. Wet grass should not be chopped. Mow a lawn that is too long or tall twice or even three times.

Issue 6: Cub Cadet Zero Turn Mower Is Smoking

When the air filter is clogged, the engine oil is incorrect, or a faulty engine gasket has allowed oil to seep onto a hot surface like the muffler, the Cub Cadet zero-turn mower will begin to smoke.

A damaged piston ring or a burned valve could be to blame when you can’t pinpoint the source of the smoke coming from your engine. My advice is to bring in a small engine mechanic to run diagnostics and figure out what’s going on.

Possible ReasonsOption
Plugged air filterSubstitute a plugged air filter.
Too much engine oilThe problem can be fixed by draining some of the engine oil from the crankcase. Be sure the air filter is in good shape.
Low engine oil levelGet a small engine expert to take a look at it. While a smoking engine caused by low oil can be fixed by adding oil, the harm may have already been done.
Bad engine gasketFind the leaking gasket in the engine and fix it.
Internal complications: piston ring or valve trainIf your engine keeps on smoking, you should have a small engine professional inspect it for the source of the problem.

Issue 7: Weak Hydrostatic Transmission

The transmission of a Cub Cadet zero-turn mower can weaken if the hydraulic oil in it has gone bad or if the hydraulic tank is empty.

A slow sensation is also possible if the drive belt or tensioner pulley is broken or worn.

Possible ReasonsOption
Bad drive beltSubstitute a worn pump drive belt
Bad tensioner pulleyAdjust the tension by exchanging the worn-out pulley. Apply grease to the tensioner arm.
Low or old hydraulic oilKeep up with routine oil changes for your hydraulic system. Do not let the hydraulic oil level drop below the full mark.

Issue 8: Mower Won’t Drive Straight or Steer Properly

If a zero-turn doesn’t go straight and pulls to one side, it could be because of the tire pressures or the dampers. If the mower’s tires are all in good shape, maybe all that needs to be done is a little tracking.

Possible ReasonsOption
Incorrect tire pressureCheck the tire pressure according to the manufacturer’s recommendations. Both ends of the zero-turn require identical tire pressures.
Bad dampersSubstitute with new dampers.
Tracking adjustment neededIf you want your tires to all rotate at the same pace, you may do that by adjusting the speed adjustment bolt. If you need help, check the handbook that came with your device.

Issue 9: Rough and Sputtering

Look for objects that can limit fuel flow or airflow or produce an intermittent spark if you notice that your Cub Cadet zero-turn is running rough and bogging down.

You should also check the ground speed, the obstruction of the mower deck, and the dullness of the mower blades, all of which can increase the demand on the engine. As the blades spin, the engine can bog down if the throttle isn’t at full bore.

Possible ReasonsOption
Old fuelUsed fuel should be drained. To stabilize the gas, add a fuel stabilizer when you refill.
Clogged fuel lineIt is possible to unclog a fuel line by removing the obstruction and blowing compressed air through the line. When cleaning the fuel line is unsuccessful, a new line must be installed.
Plugged fuel filterSwap out the fuel filter.
Dirty carburetorThe carburetor must be removed before cleaning. If it needs to be fixed or replaced, do so.
Bad gas capIf the gas cap is preventing the gasoline tank from venting, substitute it.
Dirty spark plugUse a wire brush to clean a clogged plug. If it is excessively dark in color, worn, or damaged, you should replace it.
Fast ground speedBe more considerate of the mowing conditions by reducing the ground speed. When mowing tall, thick, or damp grass, be cautious not to overwork the engine.
Low engine speedMower blade engagement requires the throttle lever to be in its highest position.
Plugged mower deckTo keep the mower deck clean, scrape it.
Dull mower bladesPut some sharpening on the mower’s blades.

Issue 10: Mower Blades Won’t Start

If the PTO switch is broken, the battery is dead, the safety switch has been disabled, or the clutch is worn out on a Cub Cadet zero turn mower, the blades will not spin.

When the belt is old, strained, has a defective pulley bearing, or the tensioner parts have worn out, the blades will not turn.

Possible ReasonsOption
Worn mower deck beltSubstitute any belts that are worn, cracked, or have a glazed appearance.
Belt falls off the pulleysSubstitute any worn or damaged deck pieces, such as a worn idler arm, a worn spring, or worn pulleys. Substitute a damaged mower deck belt.
Bad PTO switchSubstitute the PTO switch.
Bad clutchSwitch out the clutch. Substitute any worn clutch cable, lever, springs, or connections on a manual engagement clutch.
Weak batteryIf a battery tester shows that a 12-volt battery has less than 12.7 volts, the battery should be charged. When the battery stops holding a charge, you should get a new one.
Bad Safety switchSubstitute the safety switch
Blown fuseSwitch out the blown fuse for another fuse of the same amperage.

Issue No. 11: Mower is Gas Leaking

Finding the source of a gas leak in a Cub Cadet might be tricky if the gas has evaporated into the air and left no visible wet patches.

Carburetor and dry, cracked fuel lines are common places to look for leaks. Additionally, fuel leaks can occur from plastic fuel system components or from dried-out seals.

Possible ReasonsOption
Bad carburetor bowl gasketIt’s time to change up the gasket that seals the carburetor to the bowl.
Stuck carburetor float or float needleYou should cleanse the carburetor and substitute any worn components.
Cracked fuel lineSubstitute the fuel line.
Bad fuel tankWhen a fuel tank starts leaking at the seams, you need to substitute it.
Bad fuel shut-off valveThe fuel shutoff valve should be replaced.
Weak fuel filterChange the fuel filter.
Bad fuel pumpChange out the fuel pump.
Bad gas cap sealChanging the gas cap. Some caps’ rubber seals can be purchased separately.

Issue 12: Clicking and No Start

When the starter solenoid of your Cub Cadet zero-turn mower simply clicks, it’s time to replace it. It’s not enough to only verify the solenoid itself; you need also examine potential power-cutting components.

Batteries, wires, terminals, and the ground all fall under this category. If none of these are the problem, then it’s probably the starter.

Possible ReasonsOption
Damaged or loose battery cables & wiringRepair any damaged cables. Get rid of any corrosion that has formed on the terminals or other parts. Secure any dangling cables.
Weak or bad batteryIf a battery tester shows that a 12-volt battery has less than 12.7 volts, the battery should be charged. When the battery no longer holds a charge, replace it.
Bad groundClean the ground of rust. Check that the ground cables from the battery and the starter solenoid are making proper contact. (A three-post solenoid is self-grounding.)
Faulty starter solenoidIf the starter solenoid fails, substitute it.
Bad starter motorSubstitute a bad starter motor.

Issue 13: Mower Makes an Uneven Cut

There are numerous factors that might influence the cut quality of your Cub Cadet zero turn. The deck might not be sitting level because one tire is underinflated, so that’s the first thing to check.

Next, look at the condition of the parts that are underneath and on top of the mower deck. Repair old deck belts, sharpen dull blades, and replace components with faulty bearings.

Possible ReasonsOption
Dull or worn mower bladesPut some sharpening on the mower’s blades. Any blades that have deteriorated to the point where the sails are noticeably thinner than the blade’s center or the blade ends have worn and rounded should be replaced.
Bent mower bladeSubstitute a bent mower blade.
Blade installed wrongMake sure the right hardware is used to put the blades in place. The sails on the blades must face up toward the mower deck.
Bent blade spindleSubstitute a spindle that is bent. Check to see if the spindle housing is broken.
Bad mower deck belt or bad pulleysChange a deck belt that looks glazed, is stretched, worn, or cracked. Turn the pulleys slowly by hand. Substitute the pulleys if you feel a tight spot, hear a noise from the bearings, or see the pulley wobbling.
Mower deck is plugged with grass clippings & debrisScratch the mower deck.
Uneven tire pressureFix the pressure in the tires. Ensure that they are symmetrical on the left and right sides.
Unleveled mower deckLevel the mower deck so that it is the same height on both sides. The front of the mower deck is a little lower than the back. Check the owner’s manual for the exact instructions on how to level the deck.
Engine speed is too lowSet the throttle to the highest level before you turn on the blades.
Ground speed is too fastWhen mowing thick, wet, or tall grass, go slowly. Mowing under these conditions places an additional burden on the engine. Grass can be pushed over instead of cut if the mower is moved too quickly.
Operator errorOverlap routes properly so that no grass strips remain between passes. Use a small deck, like that of a push mower, to cut grass in ditches and other places where the ground slopes steeply.