14 Causes of John Deere Zero Turn Failure

Having your zero-turn mower suddenly stop working in the midst of the lawn when you’re out mowing is quite annoying.

When the engine of a John Deere zero-turn starts but quickly dies, it could be because of a lack of gasoline, air, spark, or is overheated from being overworked.

What can cause a John Deere zero-turn to break down:

  1. Incorrect or stale fuel
  2. The Fuel Filter is Clogged
  3. Obstructed gasoline lines
  4. Broken gas pump
  5. Dull carburetor
  6. Blocked air filter
  7. Blanked-out air vents
  8. Low oil pressure in engine
  9. Using too much motor oil
  10. Caused by a dirty spark plug
  11. Malfunctioning ignition coil
  12. Poor placement of the choke
  13. Leaking gas cap
  14. Mower deck blockage

Please observe all of the security measures outlined in your John Deere manual. Turn off the ignition and disconnect the spark plug wires before making any adjustments. Please give the engine some time to cool down.

14 Causes of John Deere Zero Turn Failure

Causes of John Deere Zero Turn Failure to Start, Progress, or Finish

Using stale gas in a John Deere zero-turn mower

You may blame old gas for a lot of the issues with your John Deere zero-turn mower. Make sure to only use new fuel and use it up within 30 days before it starts to degrade.

Fuel systems are susceptible to condensation because the ethanol present in most gasoline works as a magnet for atmospheric humidity. In a fuel tank, ethanol and water will naturally separate and settle to the bottom.

Component failures and fuel restrictions are just two of the problems that might arise from this combination’s damage to the fuel system and engine.

If this happens, your John Deere zero-turn may sputter and eventually stop working altogether.

RESPONSE: Make sure there’s gas in the tank. Drain the gasoline tank if the fuel has been sitting there for more than 30 days without an addition to keep it stable for longer.

Don’t use old gas in the mower at all costs. John Deere zero-turn tractors need unleaded fuel with an octane value of at least 87 and no more than 10% ethanol. Learn more about what fuel options are available for your John Deere mower right here.

Add a gasoline stabilizer and dehumidifier like Sea Foam Motor Treatment to your gas before you fill the tank. This will help your gas last longer and keep your fuel system clean.

You should put the combined gas and additive into the gas tank. Get the zero-turn rolling, and let it run for about 15 minutes to distribute the mixture.

If you’re still having trouble getting the mower going, try the next several suggestions.

John Deere Zero Turn Mower Fuel Filter Clogged

To prevent harmful debris from entering the fuel system and wearing down the engine, a fuel filter screens fuel as it is pumped from the fuel tank. This is an annual replacement item for your vehicle.

If dirt has built up in the gasoline filter to the point that no fuel can go through, the engine will stop running.

The ANSWER is to use a brand new inline fuel filter in lieu of the old one. Inspect the filter’s housing for an arrow, and position it so that it points in the direction of gasoline flow.

John Deere Zero Turn Lawnmower Fuel Lines Clogged

When old gasoline is used, it might cause the pipe to become clogged. The accumulation of the sticky substance in the pipe can restrict fuel flow.

If your John Deere zero-turn isn’t getting enough fuel because of a clog in the fuel line, it could die.

The answer is to switch off the gasoline supply and inspect each portion of the fuel line for fuel flow to see if there are any obstructions.

If you discover a clog in a fuel line, you must disconnect the line from the zero-turn and turn off the gasoline supply.

Clean the fuel line and carburetor using carb spray. In order to unclog, do this. The next step is to clear the line by blasting compressed air through it.

If you can’t get the gasoline line unblocked, you’ll need to replace it with another fuel line of the same size. Start up the engine and turn on the gas.

John Deere Zero Turn Mower with a Bad Fuel Pump

The vast majority of John Deere zero-turns use a vacuum pump. An engine’s suction is harnessed by this fuel-delivery system. Old fuel can deteriorate a fuel pump or cause it to fail.

Verify fuel flow from the fuel line to the fuel pump to establish if the fuel pump is malfunctioning. It’s possible that you completed this in the previous step.

Next, make sure the fuel pump is releasing the correct amount of fuel. Do not proceed until you have shut off the fuel supply and disconnected the fuel line from the carburetor. After stowing the line in a holding tank, you can activate the fuel flow and begin the zero-turn.

The presence of a continuous or pulsating fuel flow out of the line is an indication that your pump is functioning. To improve the fuel flow, a new fuel pump should be installed if the current one is not doing the job.

John Deere Zero Turn Mower with a Filthy Carburetor

In order to maintain engine operation, the carburetor controls the ratio of fuel to air for combustion. Gas that has been sitting about for a while might have a negative effect on the carburetor, causing it to malfunction.

Old gas’s varnish residue can clog fuel lines and stick moving components. Because of this, your John Deere engine won’t have enough fuel to keep going.

In order to evaluate whether or not the issue is in the carburetor, you need do the following inspections before dismantling it.

  • Verify that fuel is reaching the carburetor. If you’ve checked the fuel flow from your fuel pump, you already know this to be true.
  • Pull off the air filter from its housing.
  • Apply carburetor cleaner to the mower’s air filter and start it.
  • Carburetor trouble may be to blame if your John Deere starts up and seems to be running fine before slowing to a stop.

Get rid of the carburetor from your John Deere zero-turn mower. Taking it apart to have the carburetor cleaned is a must. This article will show you how to maintain your John Deere tractor’s carburetor.

If you’d rather have someone else service your lawnmower, you can do so by bringing it to a store that specializes in small engines. An alternative to cleaning the carburetor assembly is to replace it entirely.

John Deere Zero Turn Mower Air Filter Clogged

The air filter is another item that requires routine maintenance, such as cleaning or replacement. In order to prevent debris from entering the engine through the air intake system, an air filter is installed.

A clogged air filter may be the cause of your John Deere zero-turn mower’s engine performing poorly or cutting out unexpectedly.

Since zero-turns tend to be dusty places, the air filter may become clogged with debris to the point where not enough air can flow through it.

The air filter should be cleaned multiple times during the mowing season and replaced annually. Mowing in extremely dusty conditions or for profit will increase the frequency with which you must clean the deck.

Quick fix:

To maintain the efficiency of your John Deere zero-turn tractor’s paper air filter, follow these steps:

  • Take the paper element out of the air filter housing. Take care that dust doesn’t get sucked into the fan.
  • Use a clean, dry cloth to remove any lingering grime from the housing.
  • Knock out as much grime as you can from the filter by tapping it against a hard surface. Compressed air should be avoided since it can ruin the paper component.
  • To check the effectiveness of your filter, simply hold it up to the light. If the paper element is damaged, oiled, or otherwise blocking light, you should get a replacement filter. A decent rule of thumb is that if there is light coming through it, it can be used again.
  • Return the cover to the filter housing after installing the air filter.

Zero-Turn John Deere Mower with Blocked Cooling System.

It’s possible for your zero-engine turn’s to overheat, killing the vehicle. An obstruction in the cooling system may contribute to the overheating.

There needs to be adequate space for air to flow around the engine’s cylinder head and block. If debris builds up around the mower’s engine and cooling fins, the mower’s motor could overheat and stop working.

The solution is to clean the cooling fins and substitute any that are broken. Clean the area surrounding your engine’s shroud and engine block.

You may improve airflow by installing your heat shield properly.

John Deere Zero Turn Mower Engine Leaks Oil Due to Low Oil Level

Before each use, make sure the engine oil level in your John Deere zero-turn is at the correct level. The majority of lawn mower owners never do this. It doesn’t take long at all to quickly inspect the engine oil using the dipstick.

Avoiding expensive repairs by discovering a low engine level is possible. Overheating and shutting down might occur with your zero-turn mower if the engine is not properly fueled.

Without adequate oil, the internal engine parts will grind against one another, generating heat in the crankcase. Heat this high can cause engine oil and other components to start burning.

When the mower won’t start due to low engine oil, you can try topping off the oil to see if that helps get it going again.

If your John Deere has shut down, chances are good that you won’t be able to get it started again by simply adding extra engine oil.

There was probably a lot of damage to the engine. If you want to know how much damage there actually is to your mower, you should have a qualified small engine mechanic inspect it.

For engine maintenance on your zero-turn mower, a visit to a John Deere dealership or authorized engine dealer is recommended.

The John Deere Zero Turn Mower’s Engine Has Too Much Oil

It’s not just not enough oil that will kill your zero-motor; turn’s it’s too much oil.

The crankcase pressure will increase if there is too much oil. In this article, we’ll discuss the consequences of using too much oil in your vehicle’s engine.

If you check your engine oil and find that the level is excessively high, the solution is to drain off some of the oil.

A turkey baster or oil evacuator can be used to remove oil from the drain cap, the oil filter, or the oil fill area. Keep draining and refilling the engine’s oil until the dipstick reads full.

A John Deere Zero Turn Mower with a Soiled Spark Plug or Loose Connections

Your John Deere zero-turn may die due to a fouled spark plug. Inspect the spark plug in your lawnmower to see if it is dusty or the gap is off. Your mower may be running poorly because of spark plug wires that are too loose.

To fix this, take out the spark plug and scrub it with a wire brush if it’s dirty. A new spark plug should be put in if the old one is broken or has a particularly dark color.

Make that the spark plug wires are properly connected and the spacing is set per the engine manufacturer’s recommendations.

The John Deere Zero Turn Mower’s Faulty Ignition Coil

When your mower becomes heated, the winding on the ignition coil can come apart and cause a short. When this occurs, insufficient voltage prevents the spark plugs from producing a spark.

As a result, your mower may stop working after being on for a long.

SOLUTION: If the engine won’t start, examine the ignition coil for a break in continuity. If you detect a crack in the ignition coil, you should get a new one.

Misplaced Choke on John Deere Zero Turn Mower

By reducing the amount of air going into the carburetor, the choke on your John Deere zero-turn makes it possible to use a higher concentration of fuel.

When the engine is cold, you can’t start it without this. When the engine temperature rises, more air is required to keep the zero-turn going, so if you forget to release the choke, the engine will die.

SOLUTION: Check the placement of your choke lever. In order to get a cold engine going, you have to turn the choke all the way to the closed position.

John Deere Zero Turn Tractor with a Leaking Gas Cap

The gas cap is made in a way that allows air to flow through it. This will allow the gasoline tank to release excess pressure. When the gasoline tank’s vent cap stops functioning, the tank creates a vacuum that prevents gas from escaping.

Even though your John Deere zero-turn began out with a faulty gas cap, it will eventually switch off when a certain amount of time has passed. This is due to the fact that if air is prevented from leaving the tank, a vacuum will be created inside.

One way to test if the gasoline cap is the source of the problem is to loosen it slightly to let air into the tank and then start the mower to see if the engine performs better.

Whether it happens, secure the cap and give the mower another go to see if it slows down or stops working normally afterward.

If your gas cap is faulty, please replace it.

Mower Deck Drain Not Working on John Deere Zero Turn

Overworking and eventually shutting down your engine is what happens when your mower deck gets clogged.

The engine works harder to turn the blades through the accumulated grass and other trash under the mower deck. In addition, dull mower blades can make the problem even worse.

ANSWER: Sharpen your mower blades and scrape your mower deck frequently. Maintaining a clean mower deck and sharp blades not only makes for a more efficient engine, but also produces a cleaner cut.

Decks employ the blades and the space under them to generate air flow, which is then used to raise the grass and cut it.

Why Won’t the Battery Charge in My John Deere Zero Turn Mower?

Keep the engine speed high while operating the zero-turn. Don’t let your mower sit idling for too long. Battery charging is an engine-powered process.

See John Deere Lawn Mower Battery Keeps Dying for a rundown of potential battery-draining culprits.

After making sure the battery and wiring are in good shape and properly fastened, if you still have to charge it frequently, the fault may lie with the charging mechanism.

In this article, I’ll show you how to diagnose battery and charging system problems. Replace the battery if any of these tests reveal it to be defective.

If you discover that your vehicle’s charging system is malfunctioning, you should have a professional mechanic inspect it and fix it.

It’s easy to throw parts at the charging system in the hopes of fixing the problem if you don’t know anything about the charging system.

The cost of electrical components can quickly add up, and it is possible that they cannot be returned due to hygiene reasons.

Continue to Experience Issues with Your John Deere Lawnmower?

Owning a John Deere mower means dealing with a wide range of issues. Some of these issues include starting, shutting off mid-mowing, vibrating excessively, cutting unevenly, or just not moving.

I compiled a useful guide for diagnosing issues with your John Deere mower so you can figure out what’s wrong with it. For help with typical issues experienced by John Deere lawn mowers, have a look at the corresponding troubleshooting guide.