John Deere L111 Problems

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The issues you may encounter with your John Deere L111 are often common with all lawn mower models. 

You can fix your John Deere L111 problems or at least know what to do if you are aware of the causes and carry out a few simple repairs.

I share a list of possible issues you might experience when using your John Deere L111 as well as some easy-to-implement DIY troubleshooting tips for fixing them.

John Deere L111 Problems, Causes, and Possible Solutions


Before I delve into details, let’s have a quick look at these problems and their possible solutions:


Possible Solutions

1. John Deere Engine Won’t Start
  • Change the spark plug
  • Clean the fuel lines
  • Replace the fuel filter
  • Clean the air filter 
  • Charge/replace the battery
2. Engine Runs Poorly
  • Drain out the fuel tank
  • Clear the fuel delivery system
  • Change spark plug
  • Replace the air filter
  • Change engine oil
  • Unclog the mower deck
3. Electrical Problem
  • Recharge the battery
  • Replace blown fuses
  • Repair/replace solenoid
4. Fuel Problems 
  • Drain out the old fuel
  • Unclog the fuel cap vent
  • Clear the fuel lines and replace the fuel filter
  • Clean the carburetor 
5. Faulty Steering Wheel 
  • Change the pinion gear and sector gear
  • Tighten the connections
  • Seek professional help
6. Hydrostatic Transmission Failure
  • Add/replace the hydraulic oil
  • Purge the system
  • Fix any leakage opening
7. Smoke Coming From John Deere
  • Reduce oil level
  • Change the air filter
  • Replace blown head gasket

1. John Deere Engine Won’t Start

One of the most common problems users encounter when using the John Deere L111 is engine starting problems.

Don’t be too quick to overlook the most obvious causes when the engine of your John Deere won’t start. 

Whether it is a refusal to start, no cranking problem, or a hard start, there are so many reasons this could happen.


  • Worn out spark plug
  • Clogged fuel filter
  • Split/clogged fuel lines
  • Dirty air filter 
  • Dead battery 


First, check the spark plug if the engine is having starting problems. If it is worn out or has carbon build-up on the ends, replace it or clean the plug with a wire brush. 

Also, check that the spark plug wires are attached firmly to the plug.

The fuel filter and fuel lines may need replacing if the old ones are clogged or damaged. 

A dirty air filter can result in engine starting difficulty so open the air filter housing and clean/replace the air filter if it is dirty or clogged with oil.

Also, a dead engine may be a sign that the battery is dead or producing insufficient voltage. 

Use a multimeter to check the battery voltage. If it is less than 12v, the battery is dead and should be recharged or replaced.

2. Engine Runs Poorly 

In some cases, the John Deere L111 starts up just fine but then the engine begins to run poorly. 

The poorly running engine could occur in form of slow acceleration, rattling noises when mowing, rough running, excessive engine vibration, a surging mower, engine running only on choke, and many more. 


  • Stale or old fuel
  • Clogged fuel filter/fuel lines
  • Stale engine oil
  • Dirty air filter
  • Worn out spark plug
  • Carburetor problems
  • Worn drive belts
  • Clogged deck  


Poor engine performance may be the sign of a clogged fuel filter or old/dirty gasoline. John Deere recommends not using gasoline with alcohol additives. 

Change your oil at least once a season after 50 hours of active use, or the dirty oil can contribute to poor engine performance. While you’re changing oil, don’t forget to clean or replace the air filter. 

It also might be time to replace the spark plugs if your John Deere runs poorly.

Then, check the carburetor for blocked jets and bowls. 

Use a carburetor cleaner to clean the carburetor or rebuild it with a carburetor repair kit.

If the tractor vibrates or rattles excessively and you’ve tightened all loose bolts, it’s probably time to replace the drive belts. Slow acceleration is also a sign of a worn belt. 

It is good practice to regularly raise the tractor and remove all sticks and weeds that are clogging the pulleys and belts to avoid engine running problems.


3. John Deere L111 Electrical Problems

Electrical problems are quite common with John Deere mowers as with other mowers when they become old or frequently used.


  • Dead battery
  • Blown fuses
  • Damaged solenoid


Your battery may need to be recharged, especially if your L111 has been sitting for several months without being used. 

First, check the voltage of the battery and recharge it if it is producing less than 12 volts.

If recharging doesn’t help, you might need to replace the battery. If the battery terminals are corroded, clean them up and use some battery terminal grease to keep the rust away. 

Check the fuses and replace any blown ones. If the lights don’t work, try the obvious fix and replace the light bulbs.

Then, check the solenoid to ensure it is in good condition. Repair or replace it if it is not functioning properly or if it is damaged.

4. John Deere Fuel Problem

Your John Deere could be having fuel problems if it runs fine for about 15-30 minutes and shuts down on its own. 

You may notice that it starts again after sitting for 5-10 minutes and dies after running for some time. This is an indication that fuel isn’t circulating properly in the engine.


  • Stale fuel
  • Clogged fuel cap vent (vapor lock)
  • Split or clogged fuel lines/fuel filter 
  • Clogged carburetor jets


Drain out the old fuel with a siphon, clean the tank and refill it with new fuel if the fuel in your tank is stale.

Try slightly losing the fuel cap and running the engine. If it runs fine, the cap vent is blocked and is causing a vapor lock. 

Use a needle or thin wire to unclog the vent, or simply purchase a new fuel cap.

Replace the fuel filter and fuel lines if they are clogged or split. 

Then, use a carburetor cleaner to clean the carburetor jets and bowls to get rid of old fuel residue that may be clogging them.

5. Faulty Steering Wheel

The steering of your John Deere L111 can become bad and unresponsive after many years of active use. Most users complained about a popping sound when turning the steering wheel and wheel failure.


  • Damaged pinion gear
  • Worn out sector gear
  • Worn bushing


The pinion gear and sector gear are located under the mower. They become worn out over time and result in a lack of wheel control. 

Check for wear and damage in the gears and replace them if they are worn out, broken, or damaged.

If this doesn’t fix the problem, then you should contact a professional lawn mower technician to troubleshoot and fix your steering problem.

6. Hydrostatic Transmission Failure

Hydrostatic transmission failure of John Deere results in numerous problems including movement difficulty, high-pitched whining sound, and slow incline. 


  • There is not enough hydraulic oil in the transmission system.
  • Using the incorrect hydrostatic fluid/oil
  • Aeration
  • Leakage in the hydraulic system
  • The drive belt is loose/glazed


Check the level and type of fluid. If the fluid level is too low, top it up, unless the hydraulic system is sealed. If the fluid level is continuously low, look for and repair any leaks in the system.

If you used the incorrect fluid type, you may need to bleed and refill the system. Replace the oil if it becomes black or milky, suggesting overheating or water contamination.

Purge the hydraulic system if there is any air pollution or leakage. 

After that, check the belt and pulley system for damage and tighten or replace the belt as needed.

7. Smoke Coming From John Deere L111

There are many reasons smoke could come out from the John Deere engine. This, however, depends on the color of smoke escaping from the engine and where it is coming out from.

It could be white smoke, blue smoke, or black smoke. White smoke is the most common of all three.


The general reasons smoke escapes from your John Deere include:

  • Overfilled oil tank 
  • Stale oil
  • Oil-stained air filter
  • Blown head gasket


Use a dipstick to check the oil level in the tank. If it is above the ‘Full’ mark of the dipstick, it is excess and should be reduced. 

Drain out the old oil and replace it if the oil is thin, stale, or darkened.

The oil that has leaked out of the overfilled oil tank can come in contact with the air filter and clog it resulting in smoke coming out of the engine. If the air filter is stained with oil, it would be best to replace it.

A blown head gasket will also allow oil and fuel to mix up and leak into different areas producing smoke as a result. If the head gasket is damaged, replace it with a new one.

Frequently Asked Questions

How Long Does A John Deere Engine Last?

The size of the engine determines how long it lasts. Small engines can run for up to 1000 hours. The larger engine, however, can run for up to 2000 hours.

Why Is My L111 Mower Not Starting After Winter?

Stale fuel causes the slimy residue to accumulate inside the tank and carburetor over the long winter. Also, after the winter, your L111 may not start due to fuel filter and air filter clogging.

What Horsepower is a John Deere L111?

John Deere L111 comes with 20 hp Briggs & Stratton.

How Often Should I Change My John Deere L111 Engine Oil?

The engine oil should be changed after every 50 hours of active use.


Just like every other lawn mower, the John Deere L111 occasIonally develops faults. I have discussed these problems and suggested some possible solutions to solve them.

If you still can’t resolve these problems after following this guide, reach out to a professional lawn mower technician. 

Keep in mind that regular maintenance will help your mower last longer and keep the majority of these problems from arising.