Is Your Lawn Mower Surging? (Causes How to Fix). Lawn mower is surging

Is Your Lawn Mower Surging? (Causes How to Fix)

A lawn mower makes the lawn-mowing experience easy and wonderful. However, when the lawn mower itself starts facing problems, the same lawn mower can also give you a bad mowing experience.

Surging is one such problem that the engine of your lawn mower may face. It is a common fixable issue where the engine speeds up and slows down erratically, making it difficult to cut the grass evenly.

From fuel issues to mechanical problems, surging can be caused by a variety of factors. In this article, I will tell you the causes of a surging lawn mower and provide you with tips on how to diagnose and repair the surging lawn mower.

So, let’s start making your surging lawn mower normal again.

What is Lawn Mower Surging?

When the engine of a lawn mower starts running erratically, revving up and down unexpectedly, we can say that the mower is facing a surging problem.

You can diagnose a surging lawn mower from its sound because when the engine of a lawn mower surges, it sounds as if it is reaching full speed and decelerating instantly.

Both electric and gas-powered lawn mowers can face surging issues, but surging is more common in gas-powered lawn mowers.

Surging is generally caused by an uneven flow of fuel or air into the lawn mower’s engine. The uneven fuel or air flow causes fluctuations in the engine’s RPM, which is one of the reasons why your lawn mower is surging.

Causes of Lawn Mower Surging

Let’s discuss the various causes that make the engine of lawn mower surge.

1) Dirty or Gummed Up Air Filter

As I told you, the uneven air flow through the engine may contribute to surging problems. And if the air filter of a lawn mower is dirty or clogged, it will not allow the airflow into the engine properly. This will make the flow of air uneven.

The air filter of a lawn mower is responsible for preventing dirt, debris, and other contaminants from entering the engine and keeping it running smoothly. Over time, if you don’t clean or replace the air filter, it can become clogged with dirt and debris, causing the surging problem.

2) Clogged or Dirty Fuel Filter

The fuel filter of a lawn mower is accountable for filtering out dirt and debris from the fuel before it reaches the engine of a lawn mower.

Over time, if you don’t replace or clean the fuel filter, it will become clogged and will make the fuel supply to the engine uneven. And when the fuel flow becomes uneven, the lawn mower will start surging. And that’s how a clogged fuel filter becomes one of the major causes of lawn mower surging up and down.

3) Clogged Fuel Vent

There is a small hole in the cap of your lawn mower’s fuel tank. This hole ensures that there is enough air in the tank to create back pressure and avoid vacuum formation so that fuel is delivered to the carburetor properly.

Now, since this hole is too small, it can get clogged with dust and dirt while you are using your mower machine. And this clogged hole can alter the airflow and make your mower surge at idle.

4) Water in the Fuel

When the fuel in your lawn mower gets mixed up with water or moisture, the spark plug will not be able to ignite the fuel properly, and your mower machine will face a surging problem.

Well, there can be many reasons behind this, but the most common is leaving the lawn mower uncovered in heavy rain. The condensation on a hot summer day can also choke the engine and makes your lawn mower surge up and down.

5) Damaged Spark Plug

Proper working of a spark plug is necessary to ignite the fuel in a lawn mower. When the spark plug gets damaged and stops working properly, your lawn mower pulses and stops running smoothly.

6) Faulty Carburetor

The carburetor needs to work well to mix fuel and air in the correct ratio for combustion. If the carburetor installed in your lawn mower is faulty, it can cause the fuel-to-air mixture to be too rich or too lean and cause your lawn mower to idle up and down.

The carburetor generally stops working properly when it becomes clogged or dirty. In such a case, cleaning a carburetor will help you to make it work well.

But if the gasket of the carburetor gets damaged or the fuel pump malfunctions then in such cases, it is not possible to get it back just by cleaning it. In such a case, replacing the old one with a newer one is a better option.

7) Vacuum Leaks

Vacuum problems are generally caused by a loose carburetor. It is because they suck air in through crevices around the point where they are attached to the block of the engine.

This excess air makes the fuel mixture imbalanced. It also ruins the vacuum that is needed to pull fuel into the carburetor at a suitable flow rate.

8) Old and Contaminated Fuel

If your lawn mower is sitting idle for an extended period, there is a chance that the fuel lying in the gas tank of the mower becomes contaminated with debris and other contaminants. This can be one of the causes of lawn mower surging even at full throttle.

9) Faulty Governor

The governor helps you regulate the speed of your lawn mower’s engine by adjusting the throttle in response to changes in load. If the governor is not functioning correctly, it can cause the engine to pulse.

There can be many reasons why the governor of a lawn mower becomes faulty. Such causes are damaged or worn governor gear, a malfunctioning governor spring, or a dirty or clogged governor linkage.

Drawbacks of a Surging Lawn Mower: Should You Fix it?

Yes, you should get the lawn mower surging problem solved as soon as possible. Most people when start facing the surging issue with their lawn mowers, they ignore it, and don’t care to get it resolved.

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And that’s the reason here I will tell you the adverse effects of keeping your lawn mower suffer with surging. I hope these ill effects will inspire you to get the surging problem resolved as soon as you start facing it.

1) Reduces Lawn Mower Performance

If you don’t stop a lawn mower from surging its performance will decrease over time which will prevent you from mowing your lawn effectively and efficiently.

2) Increases Fuel Consumption

The engine of a surging lawn mower revs up and down, which makes it consume more fuel than a normal lawn mower. And when a lawn mower starts consuming more money, it will cost you more in the long run.

Why Your Mower Engine is Surging!

3) Difficulty in Starting

Surging may occur due to a dirty or gummed-up carburetor. Such a carburetor also makes it difficult to start a lawn mower.

4) Uneven Grass Cutting

When a lawn mower keeps surging, its engine speed fluctuates which results in uneven cutting and an unattractive lawn.

5) Loud Noise

When your mower engine surges, the engine speed fluctuates, which causes the noise level to fluctuate, making an irritating noise that the operator and neighbors won’t like.

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So, if you have made up your mind to get the surging problem fixed, it’s time to discuss how to stop your lawn mower from surging.

1) Check and Fix the Fuel Filter

One of the first steps that you need to take when your lawn mower starts surging is to check the fuel filter. When the fuel filter doesn’t do its job correctly, the fuel flow becomes uneven, which makes the mower surge up and down.

So, you first need to check the fuel filter, and if you find it to be dirty or damaged, it is better to replace it with a new fuel filter.

And in order to do so, you should first locate the fuel filter on your lawn mower. Most fuel filters are placed near the fuel tank or carburetor. Once you have located the fuel filter, remove it and inspect it for signs of damage or debris buildup.

Checking the air filter is also one of the initial steps that you need to take in order to fix a surging lawn mower.

If you find an air filter to be gummed up, you need to clean it completely. And to do so, you need to first identify the type of filter.

If your lawn mower is installed with a foam air filter, then use warm soapy water to clean the air filter and then dry it completely before reinstalling it in the lawn mower. But if the lawn mower is installed with a paper air filter, then it is better to replace it with a newer one.

If you find that your lawn mower is filled with old and contaminated fuel, you need to drain it and fill the gas tank with new and fresh fuel.

You can take a gas can, drain the old fuel in it, and dispose of it at a suitable place where it causes no harm to the environment.

As discussed above, one of the reasons a lawn mower surges is a clogged fuel vent cap. To check and clean the fuel vent cap, remove the cap and check it for any signs of dirt or debris. If the cap is dirty, clean it with a soft brush or compressed air, and then reinstall it.

5) Check and Replace the Spark Plug

A worn or damaged spark plug can’t ignite the fuel properly and cause the lawn mower to surge.

To check the spark plug, you need to remove it from the engine of the mower machine and check the electrode for signs of wear or damage. If the electrode is worn or damaged, you should replace the spark plug with a new one.

6) Check and Fix the Carburetor

To check the carburetor, first, remove it from the engine and check whether there are any signs of damage or wear. You also need to ensure that all of its components are clean and functioning properly.

If you suspect that the carburetor is the problem behind the lawn mower’s surging, you need to clean it or replace it with an older one.

7) Fix the Leaking Carburetor Gasket

If you find the carburetor gasket to be worn or damaged, the air will enter the system and make your lawn mower surge up and down.

To fix a leaking carburetor gasket, you need to remove the carburetor from the engine and inspect the gasket for any signs of wear or damage. If the gasket is damaged, replace it with a new one.

8) Fix the Faulty Governor

If you find the governor of a lawn mower to be faulty and causes for making a mower pulse, you need to adjust it or replace it with a newer one.

If you are not experienced with lawn mower repair, I will not suggest you adjust or replace the governor on your own. Rather than doing it by yourself, you should take help from a professional lawn technician.

Tip to Prevent Lawn Mower Surging Problems in the Future

In order to prevent your lawn mower from facing the problem of surging or pulsing, you need to FOCUS on the causes of lawn mower surging that I have mentioned above.

If you take a closer look at them, you will find that all these causes can be prevented by performing regular maintenance of lawn mowers. By performing regular maintenance, you won’t only prevent it from facing surging issues but you will also increase the lifespan of your mower machine.

So, my tip to prevent the lawn mower from surging, I will advise you to take care of your lawn mower and practice maintenance tasks regularly.

1) Can you fix a surging lawn mower on your own?

Yes, when the cause of the surge is normal, such as a clogged fuel or air filter, you can try resolving it on your own, but if you are not an experienced person and the causes are more complex, you should seek professional assistance.

2) Can a bad O2 sensor cause a lawn mower surging?

No, a bad oxygen sensor will not make your lawn mower surge because lawn mowers do not have oxygen sensors. Oxygen sensors are generally found in vehicles with fuel injection systems.

3) What tools will you need to fix a surging lawn mower?

Gas stabilizer, Carburetor gasket, screwdrivers, wrenches, carburetor cleaner, gas can, safety gear, etc are some tools that will help you repair your lawn mower and make it free from surging problems.

The Final Words

If your lawn mower is revving up and down unexpectedly, you can conclude that your lawn mower is suffering from surging problems. Here, I have got you covered with the causes and fixes of a surging lawn mower. If you perform the fixes that I have mentioned in this article, you will be able to make your mower normal again.

Before making any changes to your lawn mower, always remember to follow lawn mower safety precautions when working on it, and if you’re ever unsure about how to repair it, get professional help.

Lawn Mower is Surging (Revs Up and Down) – What to do

A lawn mower that uncontrollably revs up and down indicates a problem with the engine. It may happen at full throttle, when the engine is hot, or at any other time. In many cases, you can troubleshoot and fix the root cause of the issue in your own garage but complicated fixes need a professional service.

Lawnmower engine relies on a precise mixture of fuel and air to produce power. If there is anything that will make either of these exceedingly rich or lean, then it will typically result in engine surging. When a lawn mower surges, it sounds as if its engine reaches full speed, only to decelerate sharply.

Lawn Mower is Surging? (Causes and Fixes)

Engine surging commonly happens when the engine is running on an unbalanced fuel-air mixture ratio. This could be due to problems in the fuel line, faulty air system, issues in the carburetor, or bad gasoline. The following are potential reasons for mower surging and how to fix them.

Bad or old gasoline

Gasoline can degrade in as little as 30 days. Upon longer storage, fuel in a lawn mower can go bad when not stabilized. Contaminated or old fuel in a lawn mower can make lawn mower not start or may cause poor engine performance issues like sputtering, stalling, and surging.

How to Fix

If you did not empty the fuel tank or stabilize the fuel before storing your lawn mower for winter or a holiday then you need to drain the bad fuel and add a fresh one.

For a fuel tank that is nearly empty, topping off with fresh gasoline is often enough to solve the problem. If there is a substantial amount of bad fuel in the tank, simply empty the fuel tank. In this case, use a siphon or fluid extraction pump. Alternatively, disconnect the fuel line connecting the tank to the carburetor and empty the gas into a can.

Dirty clogged air filter

Air filter helps in filtering the air before it moves into the carburetor where it mixes with fuel. Over time air filters get clogged with dirt or small debris. This automatically reduces the flow of air into the carburetor. This means that your lawn mower will be running on a rich fuel mixture which results in surging.

How to Fix

You should inspect and clean your lawn mower air filter if they are dirty. If your lawn mower air filter is soaked in oil as a result of incorrectly tilting over the mower then you should opt to replace it with a new one. Similarly, for a filter that has overstayed more than the recommended time in the user manual.

Start by locating the air filter on your lawn mower, usually under a plastic cover on the side of the engine. Remove the housing cover and extract the filter. Thoroughly wash the foam filter in a wash sink or with a garden hose to clean out all the dirt. Use a rug to clean inside the housing as well.

If your filter is damaged or badly clogged, then replace it with another one. Once done, place your clean or new filter back into the housing and fit it back on the lawn mower. Surging should stop when you run your lawn mower engine if the air filter was the problem.

Bad spark plug

Spark plugs may get dirty or sooty and as a result, fail to produce and deliver the sparks needed for ignition and combustion of the air-fuel mixture. A bad lawn mower spark plug can spark inconsistently and in the process, cause an engine surge. This may also happen with a damaged or loosely fitted spark plug.

How to Fix

You’ll need to remove the spark plug and inspect it. First, disconnect the spark plug cable and remove the installed spark plug using a plug wrench or a plug socket. If dirty, simply drench its tip with a spray-on plug cleaner and gently brush it with a wire brush to remove the soot or dirt.

Replace the spark plug if its electrode or thread is worn out or damaged. Once done, insert your new or clean spark plug back into the socket and gently tighten it. Reattach the ignition cable and start your lawn mower for testing. If spark plugs were the problem, your mower should now run smoothly.

Clogged carburetor

The carburetor is where fuel and air are mixed in a regulated ratio before the mixture is delivered into the combustion chamber of the engine. In the carburetor, there are small jets where fuel and air pass through. When these jets are clogged with dirt or small debris it will automatically result in the engine surging.

How to Fix

You’ll need to remove the carburetor from the engine and inspect it. To unclog the jets, you will have to clean the carburetor and its internal components. This means locating where the carburetor is on the lawn mower and removing it to clean. You’ll need pliers and a screwdriver.

To start, disconnect the spark plug cable, shut off the fuel flow and remove the air filter including its housing. This now gives you access to the carburetor and its components. Open the carburetor and clean the innards, including the jets, float, and fuel cup. Use a carburetor cleaner solution or WD-40.

How to Fix a Surging Lawn Mower

Once done, reinstall all the components of the carburetor including the fuel line, gaskets, and throttle linkage. Fit back the air filter and reconnect the spark plug cable. Start the engine to test your lawn mower. If that is where the problem is the engine should stop surging.

Air or vacuum leaks

A carburetor is tightly sealed to the engine using gaskets. Damaged gaskets or a loose carburetor sucks in air through the resulting openings around the damaged gasket. This affects the air-fuel mix ratio and the internal suction created for a smooth flow of gasoline in the carburetor. When this happens the engine is thrown into surging.

How to Fix

Inspect and replace damaged gaskets between the engine and the carburetor. Further, tighten the bolts for a good fit of the carburetor to the engine and other attachments.

Final Thought

Engine surging can happen in both ridings or walk-behind lawnmowers. As long as it’s a combustion engine, the size doesn’t matter. Surging and hunting can affect both the performance and life of a mower engine. Fortunately, it’s something you can figure out and fix or seek the service of a professional technician.

Mower Engine Surging at Idle and How to Fix

Engines for lawnmowers are designed to be dependable and effective at cutting grass and keeping a tidy lawn. Even the greatest lawnmowers, nevertheless, are susceptible to engine surging at idle, which can cause the engine speed to constantly swing up and down.

Multiple factors could be the root of this issue, including:

After viewing this article, mower owners will quickly understand what causes Mower Engine Surging at Idle and how to resolve the problem.

Reasons Why Mower Engine Surging at Idle (Solutions Added)

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This section will examine common causes of engine surging:

Clogged Air Filter

A lawnmower engine can surge when the air filter is blocked because it restricts the airflow to the engine. The engine is unable to receive the air it requires to burn gasoline effectively when the air filter is blocked with debris, dirt, or grass clippings.

This may lead to an excessively high fuel mixture, which makes the engine run rich or lean and results in surging.

It is to note that the engine uses less fuel when it is idling since it is operating at a reduced pace. The engine won’t receive enough air to burn fuel effectively at idle if the air filter is clogged.

As a result, the engine may struggle to maintain a constant idle speed and experience ups and downs in speed. A clogged air filter can also make the engine stall or run erratically, especially while accelerating or under load.

Fix: Examine the air filter

It’s critical to routinely check the air filter and clean it or replace it to avoid surges brought on by a clogged air filter. By performing this, you can be convinced that the engine is getting enough air to idle smoothly and burn fuel effectively.

Old or Defective Carburetor

An out-of-date or damaged carburetor may not be providing the right amount of air and fuel to the engine, which might result in a lawnmower motor surging at idle.

Regulating the flow of fuel and air into the engine is the carburetor’s responsibility to ensure effective combustion. Surging could occur if the carburetor can’t carry out this task adequately due to wear or corrosion.

over, a precise amount of fuel and air at idle to keep the speed constant is important for the engine to run. The engine may receive too much or too little fuel if the carburetor isn’t working properly, which might cause the engine to surge.

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The engine may run excessively richly or too leanly as a result, which can result in additional problems including stalling, harsh running, or trouble starting.

Fix: Check the carburetor

Checking the carburetor is important when the engine is surging. It can be necessary to clean, repair, or replace the carburetor to address surging which occurs because of an outdated or malfunctioning carburetor.

A trained mechanic should perform this technique because it can be difficult. You can easily avoid carburetor faults with regular carburetor maintenance, which includes cleaning and tuning.

Faulty Spark Plug

A lawnmower engine might surge at idle due to a malfunctioning spark plug because it can disrupt the process of ignition.

For the engine cylinder’s air-fuel mixture to ignite and generate power, a spark plug must be present. Surging may occur if the spark plug is defective because it isn’t regularly igniting the fuel mixture with a strong enough spark.

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A steady spark at idle plays a great role in the engine to keep its speed stable. The engine may malfunction or run erratically if the spark plug fails, which might cause surging.

A faulty spark plug might also result in additional problems like difficult starting, harsh running, and reduced engine output.

Fix: Replace the spark plug

You may learn the importance of using the proper spark plug for the mower and proper gapping by checking the spark.

Simply execute regular checks on the spark plug, which includes cleaning and replacement at the proper intervals, to avoid the problem of surging and other challenges caused by spark plug concerns.

Loose or Damaged Fuel Lines

Due to their ability to alter the flow of fuel to the engine, loose or damaged fuel lines may result in a lawnmower engine that surges when it is idling.

The fuel lines are in charge of transporting fuel from the fuel tank to the carburetor, and then to the engine. Fuel pressure may drop as a result of broken or faulty fuel lines, which may lead to surging.

Not to forget that the engine needs a specific amount of gasoline at idle to keep its speed consistent. Fuel pressure may drop and surging may occur if the fuel lines are broken, cracked, or loose and are admitting air into the fuel system.

Fix: Verify the fuel lines

It may be necessary to inspect and replace the fuel lines if necessary to correct surges caused because of loose or damaged fuel lines.

It’s crucial to utilize the proper gasoline line type for the mower and to make sure the fuel lines are attached correctly and are not broken or kinked.

Finally, Adjust the idle Speed

One way to resolve a lawnmower engine surging problem is to change the idle speed. The pace at which the engine runs while it is in neutral and not actively mowing is referred to as the idle speed.

If a lawnmower engine surges or stalls at idle, it may be running too quickly or too slowly.

You must locate the carburetor’s idle speed adjustment screw to change the idle speed. You might need to refer to your lawnmower’s handbook to properly identify this screw, which is typically found on the side of the carburetor.

Cost to Fix Mower Engine Surging at Idle Issue

The price of a new air filter can vary from 5 to 25, depending on the retailer where you purchase the replacement filter, and the brand and model of the mower also play a role here.

Depending on the brand and model of your lawnmower and the labor rates charged by the repair shop, the cost of cleaning the carburetor might range from 50 to 150.

In general, a new spark plug costs 5 to 15. There won’t be any additional labor charges if you feel confident changing the spark plug yourself.

If you intend to repair or replace a damaged fuel line, the cost will be determined by the extent of the damage and the cost of new parts. Replacement fuel lines usually cost between 10 and 50.

Remember that these are merely estimates and that final costs may differ based on a variety of elements, including your location, the scope of the required repairs, and the repair facility you select.

Maintaining a beautiful lawn can be a daunting task, especially if you lack the appropriate know-how and tools to handle the challenges that may crop up. Fortunately, LawnAsk is here to offer you an all-encompassing resource that covers everything you need to know about lawn care.

Why Is My John Deere Engine Surging? (Answered)

To say that the Deere brand is “iconic” would be the understatement of the year… and how. The company’s stellar reputation is built on delivering capable machines that seldom let you down. Deer mowers tend to adhere to this 184-year tradition of excellence, but they are not always infallible.

John Deere engine surging is a sign of some element of the fuel delivery system either being restricted or clogged. Areas to check for a solution to the problem include: gas caps, filters, fuel lines, and spark plugs. Either regular cleanout or replacement is advised.

Today’s article focuses on an all-too-common problem: engine surging. What is it? What causes it? importantly…what are the possible solutions?

Well, stick around and find out.

Signs And Causes Of A John Deere Mower Engine Surging

It’s a lovely Saturday morning and, as usual, you bring out your trusty Deere for your weekly lawn touch-up. Only this time, the mower’s motor RPM yo-yos up and down, regardless of how hard you push the accelerator. It revs at its maximum one moment, then seemingly runs out of steam the next.

The engine doesn’t completely peter out, but this occurrence is weird…and understandably concerning. After all, these machines cost a pretty penny.

In such a scenario, chances are your lawnmower (or, more specifically, its engine) is experiencing what is known as an engine surge.

This unpredictable RPM fluctuation is the classic sign of this problem. It is an issue that can occur during acceleration or when the machine is idling. Luckily for you, it is not all that rare.

John Deere engine surging is a result of an inconsistent combustion process in the engine cylinder(s). specifically, it is caused by inconsistent delivery of fuel and/or oxygen to the combustion chamber. The usual problems lie in the air filter, gas cap, fuel lines, or carburetor.

As you know, for an engine to fire and produce power, it needs a combination of fuel, air, and a spark from a sparkplug to produce an explosion known as combustion.

To facilitate this process, a lawnmower has a fuel delivery system (fuel tank, fuel lines, fuel filters, carburetor, etc.) and an air delivery system (vents, air filters, air inlet valves, etc.). These delivery systems and your sparkplugs must be in tip-top shape and free from blockages at all times.

Therefore, if your mower is surging, there are a few ports of call.

Clogged Air Filters Can Cause Engine Surge

First, we recommend that you inspect the air filter. As the name suggests, this component is there to protect the engine from dust and debris that may be in the air. When working normally, the filter blocks these particulates and ensures clean air is delivered to the sensitive parts of the engine.

Over time, the build-up of dust and debris slows down the rate of this clean air delivery. Eventually, air (oxygen) won’t reach the combustion chamber at all or when it’s needed, resulting in inconsistent power output.

Slow Fuel Delivery Systems And John Deere Engines

The second thing you want to inspect is your fuel delivery system.

The Gas Cap

We recommend you start with simple things like your gas tank cap. These caps typically feature a small hole on the inner side. This hole is a clever piece of engineering that facilitates the creation of backpressure in the tank. This pressure helps push fuel into the fuel lines towards the carburetor.

Unfortunately, the small size of these holes makes them susceptible to blockages from dust or oils. Always check this first before completely disassembling your fuel system.

Fuel Lines

If the cap hole is not the issue, you should move on to the fuel filter and fuel lines. The filter is prone to debris blockages, especially if you use low-octane gasoline. Naturally, blockages result in inconsistent fuel delivery…which can cause surging.

Fuel lines are narrow tubes that deliver fuel directly to the carburetor. They are typically made of plastic and they are often transparent or semi-transparent, which makes it easy to spot blockages.


Next, we have the carburetor. This vital component has the delicate role of “spoon-feeding” fuel and oxygen directly into the combustion chamber. Delicate is an apt description for the carburetor, as even the smallest bits of gunk and debris can disrupt its functioning.

The carburetor is made up of a bowl, a float, and several valves. Dirt can negatively affect a bowl’s fuel carrying capacity and the movement of the float. Dirt can also block the inlet/outlet valves (commonly known as “needle valves” due to their small sizes). Regardless of the particular disruption, engine surging may be the result.

The carburetor is also prone to air and vacuum leaks when it is loosely attached to the engine block. This results in excess air flowing into the combustion chamber, which disrupts the delicate fuel/air mix necessary for efficient combustion.

Even worse, a vacuum leak will negate the backpressure required to suck fuel towards the engine efficiently. Again, the fuel/air mix will be thrown out of whack.

Since many lawn mowers and tractors today are sporting Kawasaki engines, here is another article you may be interested in… Kawasaki Engine Problems: Diagnoses, Fixes, And Tips

How To Fix A Surging John Deere Lawn Tractor Engine?

Now that we’ve identified some of the problems behind a surging mower engine, let’s talk about some of the solutions you can opt for. There are two main actions you can take for any of the problems that could arise.

To fix a surging John Deere mower engine the problem must be diagnosed and then the component either cleaned out or replaced. With parts like filters and spark plugs, replacement is the best option. Oil should also be replaced on a regular basis. Carburetors can be cleaned or replaced.

Let’s take a look at some of these specifically…

Regular Service And Maintenance

The first (and highly recommended) thing to do is ensure the machine is serviced. This involves oil changes, sparkplug replacement, and air filter replacement. Foam air filters can also be cleaned using soap and water. Paper filters must be replaced.

Luckily, Deere mowers have specific service schedules that serve as a guideline for what needs to be done at specific milestones. These guides are provided by the manufacturer and are often attached to the back (or bottom) of the operator chair.

Oil Change

Oil changes are important for the smooth movement of the engine piston and other moving components. Deere usually recommends oil changes after about 50 hours of use.

Spark Plug Changing

This is usually an easy task for most John Deere machine owners. The difficulty for most will be knowing which spark plug to replace it with.

Spark plugs are not one size fits all or even one size fits most. Many brands formulate their own size and capacity of spark plug to fit their particular machines.

For more on how spark plugs work in mowers like John Deere and other major brands, I have an article that deals specifically with them. See Are All Lawn Mower Spark Plugs The Same?

Air Filter Replacement

Air filters are an important safeguard for keeping debris out of engine lines and cyclindars. These are most often an inexpensive way to cure some seemingly major problems.

Simply changing the air filter can dramatically improve the workings of a John Deere mower. These engines are built to run well and last. Yet, even these quality machines are reliant on clean air and fuel to operate.

Regular air filter replacement can stave off problems like engine surge.

To read more on mower air filters, see my article dedicated to just that… How Often Should You Change A Mower Air Filter?

Carburetor Issues

If you are certain that service isn’t the issue, you will have to look at the carburetor, which is often the prime suspect in this case.

Most people are better off taking the mower to a repair shop. However, if you are confident, you can get in there yourself and have a look.

If the carburetor is the problem, you must take it out, take it apart and clean it.

We highly recommend a visit to Amazon for a carburetor cleaning kit with brushes and needles that you can use to push out gunk and debris. You should also dip the carburetor components in a carburetor cleaning agent to dissolve any particulates.

Finally, you must also inspect the bolts securing the carburetor to the engine block. Tighten any loose bolts you find to reduce air leaks and maintain vacuum pressure. Any worn-out gaskets between the carburetor, manifold, or engine must be replaced as these can facilitate leaks.

The Final Touches On Surging John Deere Engines…

Though John Deere is one of the leading names and manufacturers when it comes to quality lawn care products, even their engines as they rack up mowing hours can run into issues due to clogging or deferred maintenance.

Even with regular maintenance, sometimes parts will need to be either cleaned or replaced.

Engine surge itself is not the problem, but an annoying symptom of an underlying issue. Checking the parts surrounding the fuel delivery system is your best bet to diagnose and come up with a solution.

Mathew has worked in landscaping professionally for over 10 years. He is a grandpa and frequently interviews other experienced landscapers and lawn care experts who are also grandpas for these articles.

Recent Posts

Though there are many types of animals that can be nibbling on your plant leaves or flowers, there are some that you want less than others in your garden or yard. We know bunnies, deer, and other.

No one likes a clogged gutter and all the problems that come with it, from water damage to pest infestations. So now and then, we have to get our hands dirty. But what do you do when you have gutter.

About Us

We are Jerry McMillan and Mathew Booe (Father-In-Law/Great-Grandpa and Son-In-Law/Grandpa). Jerry has been in the landscaping business professionally for over 45 years and 10 of those years Mathew worked with him and helped him run his business. Together they answer landscaping, lawn care, and gardening questions of all types from hard work, first hand knowledge, and experience.

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