Top 15 Causes Your John Deere Mower Won’t Start

You may count on your John Deere mower to help you maintain a beautiful lawn, but if it suddenly stops working, you could be in a tough spot.

It may be weeks before you get your mower back from the repair shop now that the busy season has started, and the grass doesn’t stop growing just because your mower is broken.

How then do you restore normal operation to your John Deere mower? Fortunately, there are a few things you can try to fix yourself before calling a technician.

Common problems and their solutions are outlined here, ranging from faulty safety switches to spark plugs.

John Deere Mower

Gasoline System Problems

Most engine malfunctions can be traced to faults with the fuel system. They can put an abrupt end to your mowing efforts and leave you wondering what to do next.

Every piece of engine-powered equipment, including lawn mowers, need a reliable fuel system. Finding and fixing these problems ahead of time will save you time, energy, and aggravation.

Empty Fuel Tank

Check to see if there is enough gas in the tank before making any hasty judgments or getting too worried.

Problems with your lawn mower could be caused by anything as simple as an empty gas tank. If it’s low, adding more fuel can fix the problem.

If the mower’s gas tank were full, you could get back to work quickly and get back to the satisfying work of cutting grass.

If you’ve checked the gas and it’s full, but the mower still won’t start, you may need to investigate the fuel system further.

Stuck Fuel Filter

The gasoline filter is an important part to check. This seemingly insignificant component is actually crucial to the safe and effective operation of your mower’s engine.

The filter can become clogged with dirt and debris over time, preventing fuel from getting to the engine and making the mower difficult to start. If this happens to your John Deere lawn mower, try cleaning or replacing the fuel filter.

Carefully removing the filter from the mower will allow you to clean it with compressed air or a soft brush.

If cleaning the filter doesn’t fix the issue or if it seems damaged, you may need to get a new one.

Poor Quality Fuel

Unlike vintage wine, gasoline doesn’t improve with age. It slowly but steadily transforms over time, wreaking havoc on your mower’s engine.

The fuel’s volatile components evaporate after resting for months, leaving behind a sticky residue. Once a potent propellant, this material now poses a threat to your mower’s carburetor and its ability to function.

You could object, “But wait, my John Deere ran fine last season!” True, but even the most dependable machinery can succumb to the corrosive power of stale fuel.

Think about this: after only 30 days, gas starts to lose its quality. It’s a sign that the fuel in your tank has turned into a thick muck during the winter and will put an end to your mowing plans.

If you find that the old fuel in the tank is to blame for your starting issues, you should get rid of it properly. Then, clean your carburetor completely to get rid of any residue that may have built up. At long last, fill up with stabilized gasoline and enjoy the mellow purr of a well-oiled machine.

Empty the fuel tank of your John Deere before putting it away for an extended amount of time to avoid any problems. A quick fix that doesn’t cost much money but prevents hours of hassle is always welcome.

The Fuel Cap Is Bad

The fuel cap is sometimes overlooked, yet it is crucial to keeping the gas tank at the right pressure.

This seemingly innocuous component prevents fuel vapors from escaping while allowing air to enter the system. However, if the cap’s vent gets blocked or damaged, it might disrupt that equilibrium.

What, therefore, prevents your trusty John Deere from roaring to life in the face of a defective fuel cap? The secret is in the vacuum produced by a gas tank that has been improperly vented.

When running, air must be pumped into the tank to counteract the effects of the fuel being used. If a vent is blocked, no air can enter, creating a vacuum that deprives the engine of fuel.

If your gasoline cap isn’t sealing properly, here’s how to tell and fix it:

  1. Check for Damage Make sure there are no cracks or other wear and tear on your gasoline cap.
  2. Make sure there is no obstruction in the little hole at the top of the cap by performing a Vent Check.
  3. Test and replace: If problems remain after the cap has been cleaned and inspected, a new one may need to be purchased.

Failure of the Fuel Pump

Your mower’s roaring performance is powered by the fuel pump, which moves gas from the tank to the engine. However, if the fuel pump becomes dangerous, your lawnmower may die on you.

How can you tell if a faulty gasoline pump is to blame for your mower’s untimely demise? Here are some symptoms to keep an eye out for:

  1. If your John Deere mower suddenly loses power while running, then regains it briefly before shutting off completely, a broken fuel pump may be to blame.
  2. Unexpected engine sputtering or stalling can occur if the fuel pump fails, leading to an irregular fuel flow. An unlevel cut or, worse, being stranded in the middle of the job are both possible outcomes.
  3. Failure to start: An inefficient fuel pump may refuse to start the engine at all. Despite your best attempts, your trusted beast refuses to fire up, leaving you bewildered and swearing under your breath.

And the most effective strategies for defeating this cunning adversary are as follows:

  1. Inspect and test: Make sure there are no leaks or damage to the gasoline lines or connections. Disconnecting the gasoline line from the carburetor and cranking the engine is another way to check the pump’s functionality. If the fuel output is low or nonexistent, the fuel pump should be replaced.
  2. Gasoline mishap: The signs of a failing fuel pump may be caused by a fuel filter that is clogged. Always remember to replace it on a regular basis to save yourself the trouble.
  3. Replacement, the very last resort: When all other options have been exhausted and your fuel pump is beyond repair, a replacement must be installed. A new pump can revitalize your John Deere mower and have you back to cutting grass in no time.
  4. Wellness checkups: Always use clean, high-quality fuel that has been properly stored to extend the life of your fuel pump. Keeping up with routine maintenance checks is another great method to keep your mower in pristine condition and the envy of the neighborhood.

Issues with the Spark Plug

The spark plug is a crucial part of the engine on your lawnmower. It is the principal catalyst for igniting the fuel-air mixture, which gives the engine its power and smooth operation.

When this crucial part breaks, it can hinder your mower’s starting and performance. A faulty spark plug can prevent your mower from starting, as well as lead to other issues including decreased fuel efficiency, diminished power, and engine misfires.

Unsecured Spark Plug Wire

Check the wire connected to the spark plug first. If the wire isn’t properly attached to the spark plug, the engine won’t start.

If the wire seems secure and in good condition, you should check the spark plug.

Spark Plug Defects or Contamination

Spark plug condition can be evaluated by taking it out of the engine and inspecting it closely for signs of corrosion or fouling. Use a wire brush to gently remove dirt buildup, then adjust the electrode spacing in accordance with your mower’s manual.

Additionally, check for obvious signs of damage or wear. The ceramic insulator may have developed fractures, the electrodes may have become damaged, or there may be deposits of oil, carbon, or fuel.

A new spark plug should be installed if the old one is damaged or worn. Remember that spark plugs should be changed at regular intervals as part of routine maintenance, preferably every 100 hours of use or once every mowing season.

Trouble with Carburetors

The carburetor on your lawn mower regulates the flow of air and fuel into the engine. However, the carburetor will eventually wear out like the rest of the engine.

A mower’s performance and reliability will suffer if dirt, debris, and the occasional buildup of gunk are allowed to accumulate in its moving parts.

If you think your mower’s problems stem from the carburetor, you can take several measures to fix it.

Unclean Carburetor

A common initial step is to use a carburetor cleaner on the part. Clean any debris or deposits from inside the component with this specially prepared solution.

To accomplish this, you will need to unscrew the carburetor as directed by the manufacturer, clean each individual part with the cleaner, and then reassemble the carburetor.

Carburetor Problems

It’s possible that cleaning won’t fix the problem here.

If, after cleaning the carburetor, your mower still won’t start or runs poorly, you may need to replace it.

A new carburetor can be purchased from any reputable retailer, or a qualified mechanic can assist you in locating one.

However, if you don’t have much experience with engine repairs, replacing a carburetor might be a daunting task. That’s why it’s usually advisable to get help from a professional technician who can figure out what’s wrong and then fix it.

Battery Failure

In the case of electric-start John Deere lawn mowers, a dead battery could be the problem.

Verify the battery connections as a first step. They ought to be spotless and well attached. It’s possible that a dead battery is actually just the result of a poor connection between the battery and the starter.

If the wires and terminals appear secure, the battery can be tested. You can do this with the help of a voltmeter or by visiting a nearby auto parts store that does complimentary battery testing.

A dead battery means that you need to get a new one.

Keep in mind that batteries can lose charge over time, especially if they sit unused for lengthy periods of time, like during the winter when lawn mowing is not necessary. When you’re ready to start mowing again, you might find that your battery has died from lack of charge.

Purchasing a trickle charger can help you prevent this problem in the long run. The gradual, steady flow of electricity from this device is what keeps your battery charged while it sits idle. It will aid in maintaining a fully charged battery at all times.

Ignition Switch Failure

Your lawnmower’s ignition switch acts as a gatekeeper, allowing power to get from the battery to the starting. Your mower will pounce into action like a roaring lion when everything is running smoothly. But when it turns bad, it acts as a silent saboteur, abandoning you in a field.

Indicators that your John Deere’s ignition switch has gone bad are as follows:

  • The ignition switch may be the bad guy if turning the key produces no sound (no clicks, no whirring).
  • Headlight or dashboard lights that flicker or fade when you turn the key suggest a problem with the switch within the mower.
  • Touch the ignition switch (carefully) after you’ve tried to start your mower. It could be an electrical problem if it seems unusually warm or heated.
  • The Central Problem: Is it difficult to turn your key, or does it get caught in the ignition? This may indicate that the switch’s internal components are worn out or have been destroyed.

It may be time to replace the ignition switch if you find any of the above symptoms. To be sure you’re doing what has to be done for your particular model, check the handbook or get some help.

Failure of a Safety Switch

Modern lawnmowers, including those made by John Deere, feature essential safety features. The safety of the operator and the mower itself are paramount, which is why these switches have been installed.

However, they aren’t infallible and a failure or flaw could render your mower inoperable.

Bad Seat’s Switch

Check the seat switch as the first step in diagnosing the issue. This switch prevents the mower’s engine from starting unless a person is seated on it.

Even if your seat is in the correct position, the engine might not start if the switch is broken. If the seat switch isn’t working properly, you should replace it.

Faulty Blade Engage Switch

Problems with your John Deere lawn mower could not be limited to the seat switch.

The switch that activates the blades is one example. The blades of the cutter can be turned on and off with this switch.

If the blade engagement switch is broken, the engine won’t start even when the blades are disengaged. Again, look for damage or wear on this switch, and if necessary, replace it.

Problematic Parking Brake Switch

Check the parking brake switch as a final step. This safety feature prevents your mower from starting until the parking brake is on, protecting you and your property from any accidental movement.

Even if everything else is fine with your mower, it may not start if the parking brake switch is broken or not working properly. Inspect this switch carefully, and if necessary, replace it.

Stuck Air Filter

Oxygen is just as important for your lawnmower’s engine as it is for your own lungs. Your John Deere will have the same difficulty breathing as a human does when its air filter is blocked with dirt and dust.

What exactly happens when your mower’s air filter gets clogged?

It’s not rocket science. The air filter protects the engine from damage by removing debris and dust from the air before it is burned.

When the filter is blocked, airflow is drastically reduced, which increases the engine’s workload and fuel consumption. Eventually, your mower’s performance may suffer from the lack of oxygen, and it may even refuse to start.

But have no dread! It’s usually easy to get your green warrior back to full health.

To clean or inspect the air filter, take it out of the system. If it can’t be fixed, get a replacement and see your John Deere come to life again.

Air filters should be inspected after 25 hours of use, or at least once per mowing season, as recommended by experts. If you give your John Deere a regular dose of oxygen, it will continue to be ready to work anytime your grass needs tending to.

The Summing Up

It’s annoying when your John Deere lawn mower won’t start. However, the issue at hand can be discovered with persistence and investigation.

It’s important to use caution before diving headfirst into an exploration of the inner workings of your lawn mower. When in doubt about how to solve a problem, the owner’s manual is your best resource for gaining familiarity with the model’s specifics.

With this information in hand, along with some common sense, you should be able to tackle the challenge head-on. It could save you both time and money if you investigate these possibilities on your own before calling in the experts.