7 John Deere D140 Problems And Their Fixes You Must Know

People are fond of John Deere mowers. This manufacturer is popular for some of their durable high-powered tractors and mowers.

Consumers cherish John Deere mowers due to their significant amounts of raw power and modern conveniences. More significantly, their reasonable price tags make them easily accessible to those with smaller plots of land.

The John Deere D140 is a top-picked model that usually sees good user reviews. It’s praised for its powerful 22hp engine that can easily mulch even the tallest grass. However, although it’s a good purchasing choice, it is not without problems.

Some common problems with John Deere D140 includes:

  • Engine Issues
  • Machine Isn’t Starting
  • Transmission Problems
  • Steering Issues
  • Electrical Issues
  • Fuel Issues
  • Black Smoke Emissions

So, if you are looking to purchase the D140 model, read this article to be aware of the common problems you can encounter with this machine.

7 Common John Deere D140 Problems & Solutions

Common John Deere D140 Problems & Solutions

Undoubtedly, the D140 is one of the fantastic lawn mowers by John Deere. But, you will likely face some minor issues which you can solve quickly by yourself or with the dealer’s help.

Moreover, the problems can show up quite randomly, not every time. So let’s explore the common issues with the John Deere D140 and the correct solutions to resolve them.

1. Engine Issues

One of the most common user complaints is that their John Deere D140 engine misbehaves. The engine isn’t starting, producing excessive smoke or noise when started. And in the worst cases, the engine may not take a start at all.

Major possible things that can cause engine issues in your mower include:

Old, obsolete, and oxidized gas. This can lead to significant power loss.

If this problem remains very long, it damages the engine’s mechanism. Eventually, the engine fails to run untimely.

It is overheating the engine. The engine can even lose power now and then while mowing. Such a condition can occur due to clogged or corrupted engine premix that prevents the engine from running the mower correctly.

The Fix:

If the engine issue is due to an old gas mix, replace it immediately. Water often gets mixed with gasoline, resulting in oxidation that often disrupts the smooth fuel flow to the engine. Eventually, it can’t operate at full power.

You are recommended to use gas with a lower amount or ten percent of ethanol. Ethanol-free gas can resolve the engine problem. Consider replacing the old gas with a fresh one. Poor-quality or old gas mixes can hinder the tractor’s ability to run efficiently.

However, in case of a faulty premix, you must drain the fuel line and gas tank and eliminate all the debris. Then, you can opt for installing a fresh mix of the premise.

2. The Machine Isn’t Starting

The starter utilizes a small battery for engine ignition to keep it running. When this part turns unfunctional or breaks, the mower won’t start.

The Fix:

You must start troubleshooting this issue by disconnecting the machine’s power sources. The power sources are electrical wires, fuel wires, spark plugs, and batteries.

After completing this, check the starter and voltage with a voltmeter. First, set the voltmeter to the DC, followed by connecting wires to the positive and negative sides of the starter. Now after turning the key, see if your mower starts. Also, keep an eye on the voltmeter screen’s display to see if it displays a current.

It can indicate that the starter has failed if it doesn’t display the current. So replace it if necessary.

3. Transmission Problems

Many users have even reported transmission issues with the John Deere D140 mower. It causes the machine to run at reduced speed.

Transmission problems often occur when a mower uses too much load, especially on bumpy or uphill terrain that puts immense pressure on the transmission.

The Fix:

First, assess the fuel levels, the engine, and the exterior like you do in case of other problems. Then, start disassembling the transmission for inspection.

Check the gearbox. If you find it strained, it will be quite clear where the issue lies. For example, a strained gearbox won’t allow your mower to maintain enough speed or push up slopes.

John Deere mower’s transmissions don’t possess a drain stop or fill cap as they aren’t designed to be drained or filled. So if the fluid viscosity gets hindered, the transmission won’t cause movement. However, you will have to replace the transmission with a new one in such a scenario.

Check the fluid level. The transmission fluid helps to change the ears efficiently, which is necessary for the engine’s overall performance.

When the fluid level is too dense or low, the transmission utilizes more power to run the engine. So replace the fluid if it has poor viscosity or is too dark.

Otherwise, get help from a John Deere dealer to resolve the transmission problems.

4. Steering Issues

If it’s a steering issue, you won’t be able to turn the mower smoothly and feel unresponsive and stiff. The steering wheel can even vibrate excessively, indicating an issue with the tires or wheels. A key reason behind this problem is that the tire pressure is too low.

The Fix:

To fix the excessive vibration of the steering wheels, check the tires to ensure they have the right air pressure.

In the worst case, the problem might be with the steering shaft or the support assembly. You must examine and fix these elements as required.

5. Electrical Issues

While both electrical and starter issues produce similar consequences, it can be confusing to understand where lies the real problem. So you can check the transmission to fix any issues and inspect the electrical outlets.

However, the spark plug is typically a key indicator of an electrical problem. So let’s see how to fix any issues with the spark plug.

The Fix:

Use a wrench and pliers to unclasp the spark plug from both sides of the engine. Then, clean any filth or debris from it with sandpaper, emery board, or simply your hands, as even the tiniest bit of it can instigate a misfire.

Check the metal connector and replace it if necessary. And it should be tight. Moreover, replace the rusted or corroded spark plug. They are affordable and available at nearly all mechanical outlets.

6. Fuel Issues

Another issue you can encounter with the John Deere D140 is a chronic fuel problem. You can understand whether your machine is having fuel commotions by the symptoms like poor fuel, troublesome fuel pumps, and cracked gasoline hoses.

Dirt can even accumulate at the main fuel’s bottom, obstructing fuel.

The Fix:

After disconnecting the hose, let the fuel flow freely, and the gas escapes. Then, reconnect the hose to the filter. 

Following this, blow air inside the gasoline line and clean it. Don’t try to dissipate the pressure at once; instead, let it dissipate slowly. 

This solution should fix your mower’s fuel issues.

Also Read: Lawn Mower Oil Type: What Kind Suits My Engine?

7. Black Smoke Emissions

Black smoke can indicate serious damage to the engine. However, it may only sometimes be the situation. Sometimes, black smoke also occurs due to the accumulation of debris, dirt, or burning of old engine oil.

Fortunately, a few simple steps can help you fix this issue.

The Fix:

The air filter can get choked up with oil or dirt, so clean the air filter first. However, if it appears much older or oily, replace the air filter.

On the other hand, you may also find the throttle to be partially engaged. It causes continuous burning of the engine oil when idle. So check and adjust the throttle to make sure it’s entirely closed.

The Takeaway: Is John Deere D140 a Good Deal?

The Takeaway- Is John Deere D140 a Good Deal

The John Deere D140 is undoubtedly an excellent entry-level lawnmower. Moreover, consumers have considered it an ideal tractor for the ones investing in a mower for the first time.

It’s a perfect everyday mower for a medium-sized terrain and can easily tackle 2-4 acres. Another factor why people love this model is that it can perform reverse mowing conveniently. 

However, you can find some troubles with this John Deere D140 mower. Still, it’s a common scenario with all mowers from John Deere and other manufacturers. More significantly, you can bypass most of these problems with proper maintenance.

Eventually, this great mower will accompany you efficiently for many years, giving you a great experience.


What engine powers the John Deere D140?

The John Deere D140 lawnmower is powered by Briggs & Stratton 40 2-cylinder air-cooled engine.

What horsepower is the John Deere D140 mower?

The John Deere D140 lawn tractor’s 2-cylinder engine delivers 22 horsepower, making mowing smooth and quick.

Is the John Deere D140 hydrostatic?

Yes, the John Deere D140 is a 48-inch hydrostatic riding lawn mower.

About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

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