Why are my Cub Cadet mower blades not engaging?

If the PTO clutch is not getting power, if the clutch solenoid is defective, or if the clutch is worn out , the lawn mower blades will not engage. The PTO clutch is not repairable—if the clutch is defective, you must replace it.

Why is my riding mower cutting deck not engaging?

Belt-the number one cause for your blades not to engage is that your belt is either stretched or loose causing it to slip or fall off completely . Belt could have snapped also. When you are trying to process too much grass/leaves they could pack up under your deck and push off your belt.

Why are the blades not turning on my riding mower?

If the blades are not rotating, put the ride-on mower into the service position and check for grass, branches or other debris . If the cutting deck is dirty, clean it by removing all branches, grass or debris.

How do you engage the blade on a Cub Cadet riding lawn mower?

To engage the blades, be sure that your throttle or choke is in the rabbit position. Then, push the PTO or blade engage lever forward into the on position .

Why does my cub cadet stalls when I engage the blades?

That is most likely the seat safety switch not making good connect . Very common issue. Lift up the seat and the switch will have a small wiring harness attached to it. Make sure the wiring harness is attached firmly.

Will a weak battery cause PTO not to engage?

Yes - one wire goes from the switch to the relay.

Why does my riding mower shake when I engage the blades?

If the mower vibrates when you engage the cutting blades, there might be a problem with the blade drive system. Deck vibration can be caused by an unbalanced blade, worn pulley or mandrel, bad blade belt or debris caught inside a pulley. Loose nuts or bolts on the pulleys, mandrels or blades can also cause vibration.

How does a PTO work on a riding lawn mower?

The PTO (or power take-off) belt is part of a pulley system that operates the blades on your riding lawn mower. It runs off the electric clutch system in your engine . If you hear squealing during operation or see dry rot on your PTO belt, you may need to replace it.

How do you know if your PTO clutch is bad?

The PTO clutch will not engage or disengage You'll need to disassemble and inspect the clutch to see what's wrong and replace parts as needed.

How do I know if my mower deck spindle is bad?

If you hear strange noises coming from your mower deck, it may be a sign that the spindle is damaged. A bad spindle can produce grinding, rattling, or squeaking sounds, which indicate that the bearings are worn out or the spindle is bent.

Should I angle my mower deck?

For most effective results, a lawn mower deck should have a pitch, or height difference of 1/8-inch to 1/2-inch between the front of the deck to the back of the deck . Naturally, this makes the sweet spot about 1/4-inch of pitch, depending on the mower model.

Why does my lawn mower starter spin but not engage?

If the starter motor spins but does not crank the engine, you likely have a problem with... Faulty or damaged battery . To address this issues, check the battery and charging system for problems.

How do I know if my lawn mower fuse is blown?

First, check for a blown fuse because you can usually see a blown fuse just by looking at it . The fuse on most riding mowers is connected to the small red wire that connects to the starter solenoid post. Check the fuse and replace it if it's blown.

Do Cub Cadet mulching blades work?

Product works great. No lawn clippings to clean up. Not sure why cub cadet doesn't just build the mowers with the mulching kits from the start.

8 Reasons Cub Cadet Mower Blades Won't Engage or Turn On (2024)

You have a riding mower or a zero-turn mower and your blades won’t turn on. What good is a mower when you can’t get the blades to engage?

Cub Cadet mower blades won’t engage or turn on when the deck belt is worn; the tensioner arm or spring is worn; a pulley is bad; the PTO switch is faulty; the clutch is bad; the battery is weak, or the fuse is blown.

Always follow the safety precautions found in the Cub Cadet operator’s manual before performing any repairs. Always remove the ignition key and spark plug wires.

8 Reasons Cub Cadet Mower Blades Won't Engage or Turn On (1)

This post may include affiliate links. Purchases made through these links may provide a commission for us, at no extra cost to you. As an Amazon Associate, we earn from qualifying purchases.

Follow all safety instructions provided in your equipment operator’s manual before 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.

Table of Contents show

Cub Cadet Mower Blades Won’t Engage or Turn On

Worn Deck Belt

When the mower deck belt is worn, it can slip on the pulleys and fail to turn the mower blades. Inspect the belt and check for visible signs of wearing including cracks, wearing, fraying, or a shiny appearance.

Belt Came Off the Pulleys

The belt may have come off the pulleys causing your mower to fail to turn the mower blades. I have listed a couple of common causes for this here.

Check out Why Your Cub Cadet Belt Keeps Coming Off or Breaking for additional items that cause this to happen.

Worn Idler Tensioner Arm & Spring

You will find a tensioner arm and spring that holds the idler pulley in line. The bracket typically has a pulley on one side and a spring on the other side.

The hole in the bracket where the spring is attached can become worn or the spring itself can become worn. This can cause the belt to become loose and vibrate off the pulleys.

Worn Pully Bearing

A Cub Cadet belt that is coming off your mower can be the result of bad bearings in your pulleys. Bearing failure can cause a pulley to move so it no longer sits flat and parallel to the deck.

One side of the pulley should not be sitting higher off the deck than the other. The belt can roll off a pulley that isn’t running flat. Replace a pulley where the bearing is found to be bad.

Faulty PTO Switch

The PTO switch is usually a knob installed on the mower that allows voltage from the battery to power the clutch. When the switch fails, the blades won’t turn on.

Check for continuity in the switch. Replace a switch with a break in continuity.

Bad Clutch

The PTO (Power Take Off) clutch transfers power from the engine to the blades by engaging the drive belt. A clutch that is worn or faulty must be replaced when it fails to power the blades.

For more details on clutches, check out A Look into How Lawn Mower Clutches Work.

Worn Clutch Cable on a Manual Clutch Mower

You will find a clutch lever and cable on a mower with a manual engagement clutch.

Check the condition of the clutch lever, cable, spring, bushings, and linkages to make sure the clutch is being engaged and the parts are not worn

Replace any worn parts.

Weak Battery

An electric clutch uses power from the battery. When the battery is weak, it is unable to provide sufficient power to the clutch solenoid to engage the mower blades.

Check the voltage of the battery using a multimeter. A fully charged 12-volt battery should give you a reading of about 12.7 volts.

Charge the battery when you get a reading less than this. If your battery continues to die you can find common things that are causing this in 5 Things That Are Draining the Life of Your Lawn Mower Battery.

Charge a Cub Cadet Battery: Use a battery charger to charge a battery. Before you continue, wear protective gear to protect your skin from electrical shock and protect your eyes. Follow these steps to charge your riding mower or zero turn battery with a charger:

Access the battery and terminals. You may need to use a screwdriver to uncover the battery. You will find the battery under the hood or under the seat. Do not remove the battery from the casing.
Connect the battery charger cables beginning with the positive cable first. This is the red cable or the one with the plus sign. Place the cable on the positive battery terminal.
Attach the negative cable to the negative battery terminal. This is the black cable or the one with the negative sign.
Do not touch anything that doesn’t have a rubber coating to prevent electrocution.
Set the charger’s voltage and amperage level to the desired level. The average volt level for lawn mower batteries is usually 12 volts. More amperage charges the battery faster. Start with two amps and work up to no more than 10 amps. A slow charge is best.

If you find the battery won’t hold a charge, you must replace it with a new battery. You can find 12-volt lawn mower batteries at your local hardware or automotive store. You will also find batteries at your local lawn mower dealership.

Bring the old battery with you. Most places will charge you a core fee unless you provide them with your old battery. Core fees average $20.

Bad Safety Switch

A Cub Cadet uses a safety switch in the seat as part of its operator presence system. The seat switch is installed under the seat to sense when the mower operator is in the seat.

As part of the safety system, the lawn mower blades won’t turn on without the operator in the seat.

If the seat switch fails to work, it may not properly sense the operator. The safety system will prevent the blades from engaging with a bad seat switch.

Test the seat switch using a multimeter or youcan temporarily bypass the safety switch to identify a bad switch. Do not operate a mower without the safety switch installed for your safety.

Always have safety switches installed and working on your equipment.

Blown Fuse

When you aren’t getting power from the battery to the clutch, you may have a blown fuse. The fuse is used to protect the Cub Cadet’s electrical system.

Replace a blown fuse with the same size fuse. If you continue to blow fuses, I recommend taking your mower to a Cub Cadet service dealership or a lawn mower repair shop to find the root cause of the electrical failure.

Still Having Problems with Your Cub Cadet Mower?

If these tips haven’t solved your problem or if you are experiencing a different problem with your mower, check out my guide showing the most common issues and solutions: Common Cub Cadet Problems.

Here you’ll find the causes of issues like the mower not starting, a bad cut, a vibration, or a smoking problem. I include solutions along with links to more in-depth information.