Your John Deere lawnmower stops running in the heat (This is Why)

Your lawn mower has been cutting grass for some time when all of a sudden it stops. This is a typical incident that many homeowners go through at some point while their lawn mower is in use.

A stopped air filter, old fuel, a dirty carburetor, the incorrect type of engine oil, too much or too little engine oil, clogged cooling fins, a faulty ignition coil, a faulty fuel cap, or a plugged lawn mower deck can all cause a John Deere lawn mower to shut off when it’s hot.

Observe the safety instructions included in the user’s manual. Prior to making any repairs, the spark plug wire should always be removed. Hold off until the engine has cooled and all moving parts have stopped.

10 causes of a John Deere lawn mower turning off when it gets hot

Filter plugged into a John Deere lawn mower

When the mower stops off, I inspect the air filter first. When mowing in filthy, dusty circumstances, the air filter may clog, preventing the engine from receiving a good flow of air.

Your John Deere mower won’t run if there isn’t enough air for combustion to occur in the engine.

Before each use, it’s crucial to check the air filter to make sure it’s in good shape. Every season, I like to start with a fresh air filter and change it multiple times as the season progresses.

You will need to clean and replace the filter more frequently if you use your mower more frequently than the typical homeowner.

Here are the cleaning procedures for a paper air filter and foam pre-filter (if your engine uses a foam pre-filter). Consult your operator’s manual for information on all other types of filters.

Make a John Deere paper air filter cleaner

  • From the air filter housing, remove the air filter.
  • Clean the housing of any leftover dirt. Avoid letting dirt or other material enter the air intake.
  • Remove the pre-filter if your filter has a foam one.
  • To remove as much dirt as possible, shake the paper air filter against a hard surface.
  • To see if light is passing through the paper in your filter, hold it up to a light source.
  • If you can see light coming through the paper element of the filter, reuse it. If there is no light, the filter is very dirty, covered in oil, or it is damaged, replace it.

The John Deere Foam Pre-Cleaner should be cleaned because it works in conjunction with a primary paper filter. A foam pre-cleaner SHOULD NOT BE ADDED OIL. The paper filter might be harmed.

  • Make sure the filter is in good shape by looking it over. It’s time to buy a new one if it is cracked, ripped, or has black patches.
  • To clean the foam filter and get rid of the oil and grime, use water and a mild detergent.
  • Rinse until the water is completely clear and all soap has been eliminated.
  • Lay flat to air dry after squeezing out extra moisture. The drying process will go more quickly if you expose the filter to the sun.
  • Place the foam pre-cleaner onto the paper filter after it has dried.

A John Deere lawn mower has bad or outdated fuel.

Old gas is another factor that could stop your mower from working. A John Deere doesn’t simply stop running when the gas runs out.

Varnish is left behind as old gas degrades and accumulates over time in the fuel system. The varnish and gooey deposits might lead to fuel constraints, and after using your mower for a while, it might eventually stop working.

Use the right kind of gas and learn how to handle and store it properly to reduce future fuel-related problems. For further information, see my post This is the Gas to Use in Your John Deere Lawn Mower.

FIX: Use a siphon to remove the old gas from the fuel tank and properly dispose of it. To stabilize and clean the fuel system, combine new gas with a fuel additive. Add it to the gasoline tank after mixing.

Of order to clean the engine and fuel system in your John Deere, I advise using a solution called Sea Foam Motor Treatment. Read my article here for additional information on the benefits of incorporating sea foam in your fuel system.

Check out my post on why a John Deere isn’t getting gas for more causes of a lack of fuel if you still have a blockage in your fuel system after changing your gasoline and using a fuel system cleaner.

A John Deere lawn mower’s dirty carburetor

In order to start and run the mower, the carburetor mixes gasoline and air to produce combustion in the engine. Old gas deposits have the potential to clog the fuel jet and make minor internal components stick.

When a John Deere mower grows hot and insufficient gasoline isn’t going to the engine, a carburetor malfunction may force it to stop.

Verify that the carburetor is receiving a sufficient amount of gasoline before trying to isolate the problem to the carburetor. If not, you should check the fuel filter, the fuel line, or the fuel pump for obstructions.

Remove the air filter next, then spritz the air intake with carburetor cleaner. Allow the mower to run after starting it. You can have a problem with the carburetor if it starts to run slowly and then shuts down after the carburetor cleaner is burned.

Solution: By following the directions in this manual, you should be able to disassemble and clean your John Deere carburetor if you are a bit mechanical and don’t mind handling small parts.

Unsure of how to go about cleaning your carburetor? Have it cleaned by your neighborhood lawn mower repair business. Buying and installing a new carburetor is an additional remedy for your carburetor problems.

John Deere lawn mower with the incorrect engine oil

Use air-cooled engine oil with a high zinc content wherever possible. A cooling agent, zinc is an addition.

This kind of oil is distinct from the oil used in automobiles. A car’s engine is cooled by a liquid of water, whereas the little engine of a John Deere gas lawn mower is cooled by air.

The majority of manufacturers of lawn mower small engines advise using SAE30 or 10W-30 engine oil. If you are operating in an environment with greater ambient temperatures, you might need to switch to 20W-50 oil viscosity.

To avoid overheating your engine, use this chart and your owner’s handbook as a guide for choosing the right engine oil for your lawn mower.

outdoor-John Deere Lawn Mower
                          outdoor-John Deere Lawn Mower
Kawasaki Engine Oil Viscosity & Temperature Chart

Drain the engine oil as a solution. Use the viscosity that the engine manufacturer recommends is adequate for the surrounding temperature to fill the crankcase with new oil.

An overfilled John Deere lawn mower with engine oil

Your John Deere lawn mower’s engine may shut down if there is too much engine oil in it. The crankshaft and rod have to push through extra oil when there is too much of it, which prevents them from easily rotating.

As the engine heats up, it may increase crankcase pressure and place internal components under stress, causing the engine to stall.

In addition, when too much oil smoke clogs the air filter, the engine may run poorly and shut off. Your mower can stop while you’re mowing if the filter can’t get clean air.

Remove any extra oil from your John Deere lawn mower so that it is filled to the manufacturer’s recommended level. After removing the spark plug wire, drain a small amount of oil using one of the following techniques:

  • Drain Plug: Remove and replace it quickly to only drain a little amount of oil.
  • Remove the oil filter from the vehicle. Prepare a rag to collect a small amount of oil from the filter.
  • Some push mowers won’t have an oil filter or drain plug. Oil fill hole To get some oil out of the oil fill hole, you’ll need to tip the mower over. When tilting your mower, keep the air filter and carburetor on the upper side.
  • Oil Extractor Pump: Vacuum a little oil from the oil fill area using an oil evacuator.
  • Use a turkey baster to extract a small amount of oil from the oil fill.

A John Deere lawn mower has insufficient engine oil.

Your John Deere may break down when it gets hot if the oil level is lower than the manufacturer’s suggested amount. Oil is necessary to lubricate the engine’s internal components and ensure smooth operation.

When engine oil is running low in a mower, friction in the engine increases as the fluid heats up and thickens.

RESOLUTION: You might try replacing your engine oil and adjusting the level. The basic solution of an oil change will typically not work once your mower shuts down due to running out of oil.

You most likely have internal engine damage that has to be carefully diagnosed by a small engine mechanic using testing.

John Deere lawn mower engine cooling fins that are broken or clogged

You should clean the cooling fins on your engine once a year and keep an eye on them throughout the season. The fan might become clogged with debris and grime, making it unable to circulate air over the engine block and cylinders to keep them cool.

Your John Deere may shut off due to a damaged or clogged cooling fin or an accumulation of debris around the engine.

SOLUTION: Clear away any debris from near your cooling fins, and replace any that are damaged. Make sure the heat shield is firmly in place and clear out any debris that has accumulated under your engine shrouds.

John Deere lawn mower with a bad ignition coil

Your John Deere may shut down if the ignition coil overheats and stops functioning. The coil’s windings separate and short out. A malfunctioning ignition coil won’t be able to supply the spark plug with enough voltage.

First, make sure you are using a reliable spark plug. Next, examine your ignition coil with an ohmmeter to make sure there is no break in its continuity. If you come across a bad coil, replace it.

defective John Deere fuel cap

A vent that permits air to enter through the gas cap on a John Deere tractor is incorporated into the cap. This is important to maintain an equal air pressure inside and outside the tank.

Air must be able to exit the tank since it is displaced when fuel is added. Air must be able to enter the tank as the fuel is spent. If the vent on the gas cap is blocked, then this is impossible.

A blocked fuel tank vent will prevent fuel from flowing since the tank will become vacuum-sealed because air can no longer enter it. A John Deere will eventually shut off as a result of this after running for some time.

If the mower starts running while the gasoline cap is loosened to let air into the tank and stops after a brief period of operation with the cap on, the solution is to replace your gas cap.

In addition to giving you a poor cut, a clogged mower deck and worn out blades can overload the engine, causing the mower to bog down and stop.

Each revolution of the mower blades through a pile of waste requires the engine to work harder. The engine is put under more stress as a result, which may cause it to bog down and quit.

Along with a clogged mower deck, worn-out mower blades will exacerbate the issue, overloading your engine and causing it to shut off.

To preserve your John Deere’s cut at its finest and save the mower from being overworked, sharpen your mower blades and scrape the deck.

When the grass is damp, avoid mowing it. Wet grass is more likely to clump in your yard and collect beneath the deck.

A John Deere lawn mower has dull blades and a clogged mower deck.

Not only will a clogged mower deck and dull blades leave you with a bad cut, but it can also cause the mower to bog down and quit because the engine is under load.

The engine must work harder to move the mower blades through a bunch of debris with each turn. This causes extra strain on the engine that can cause it to bog down and quit.

In addition to a clogged mower deck, dull mower blades will further magnify the problem causing your engine to overload and shut down.

SOLUTION: Sharpen your mower blades and scrape your deck to keep your John Deere’s cut at its best and prevent the mower from being overworked.

Avoid mowing the lawn in wet conditions. Wet grass is more prone to collecting under the deck and clumping in your yard.