Why is My Lawn Mower Blowing White Smoke?- How To Fix

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Several causes of smoke come from your lawn mower that don’t need professional help. If a homeowner notices their lawnmower is smoking, they can typically tell what’s wrong by looking at the color of the smoke coming from the engine. 

Lawn mowers are notorious for being difficult to operate, mainly if the operator has never used one. When you use a mower, you risk encountering several irritating side effects, including smoking, sparking, and loud sounds. Surprisingly, the appearance of white smoke emanating from a lawn mower is not always a sign that it has to be replaced.

There are a lot of things that might be causing smoke to come from your lawn mower, and some of them may need the assistance of a professional. If a homeowner discovers that their lawnmower is smoking, one of the first things they should do is look at the color of the smoke coming from the engine. It will help them determine what the problem is.

Always remember that although all mowers powered by internal combustion engines have a standard set of components, the specific arrangement of those elements varies significantly from one brand and model to the next.

Causes of Lawn Mower Blowing White Smoke And How to Fix it?

Causes of Lawn Mower Blowing White Smoke and How to Fix It
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Despite appearances, white smoke is not as dangerous or deadly as it may seem. Fortunately, the problem is easily solvable. Even if you can’t pinpoint the source of the smoke right away, trying out other potential causes and remedies is always a good idea.

1. An Overturned Lawnmower

An Overturned Lawnmower
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First, let’s address the most straightforward reason for lawnmower white smoke. Have you ever tilted your lawn mower over 15 degrees?

Possible explanations include stowing it that way and then mistakenly moving it. Likewise, you’ll know without a doubt whether this is the root of the problem.

Most folks run into this trouble while emptying the chute or cleaning up the storage area under the deck. If they do that, the oil will migrate from the crankcase to the cylinder, causing your lawnmower to smoke once you cut it again.


The best thing to do is to remove any apparent oil from the engine and let anything in the combustion chamber or internal components burn up when the engine starts and runs. 

You shouldn’t notice any more white or blue smoke until the oil has completely burnt out. Make careful to check the air filter if you think this is the case, since a filthy filter might be the source of the smoke.

You should change the air filter and inspect and clean your carburetor if there’s a noteworthy amount of oil.

2. A Leak in The Oil Seal

A Leak in The Oil Seal
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A precise quantity of oil should be used in your engine. While the amount of oil needed by a lawnmower engine is much less than that of a vehicle, it still serves a vital purpose.

It will suffer when there is too much or too little oil in the engine.

Because of the frequent nature of oil changes, it is simple to overfill the oil reservoir accidentally. One cause of the smoke is that you recently replaced the oil in your lawn mower after seeing a low on oil.


If the oil level indicator on the dipstick rises over the maximum level, you should remove some of the extra oil from the crankcase. Depending on the model of your lawnmower, this may be a breeze or a serious hassle.

The simplest method is to empty the oil and then put it in the specified quantity.

After you have completed this procedure, double-check that your lawn mower has the proper quantity of oil. Some believe adding a tiny amount of additional oil won’t affect anything, but that’s not entirely accurate.

Even while under filling is terrible, having too much oil may cause the engine to overheat, smoke, and work harder.

3. Oil-Related Problems

Oil-Related Problems
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A little more than a pound (almost 0.5 L) of oil should be plenty for your lawnmower. Understandably, you sometimes overfill the crankcase with such small quantities.

It happens often. It is possible to avoid it by carefully inspecting the level and amount before mowing.

It’s common to assume that a bit of oil won’t affect anything, least of all your lawnmower’s motor. As splash lubrication is used in most engines, having oil over the paddles would hinder performance.


You can probably get away with using the 2-stroke lawn mower until it runs out of gasoline if you are sure there is just a little oil in the fuel. 2-stroke engines are very reliable since they are designed to burn an oil/gas mixture.

It’s essential to take extra precautions while working with oil in the gasoline of a four-stroke mower.

Since this is the case, replacing fuel gas with clean gas is your best bet. A 2-stroke mower with a nearly full tank is in the same boat. After that, you should check the oil level and replenish any that may have been lost in your mower’s engine.

Some further white or blue smoke may be produced when the remaining oil is burned.

Also Read: How to Change Oil in Lawn Mower?

4. Damaged Piston Rings

Damaged Piston Rings
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Inadequate maintenance, namely worn piston rings, is a frequent cause of smoke in lawnmowers. The piston ring’s job in an internal combustion engine is to seal the piston to the cylinder wall.

Oil will flow past the piston rings and into the combustion chamber if this seal fails due to wear, strain, or corrosion.

When this occurs, white smoke will be released from the motor. Other problems with your lawnmower may also cause piston ring smoke, such as a lack of fuel, a dirty air filter, or faulty cylinders.


Depending on the mower you have, you may change the piston ring on your own in less than 30 minutes. However, be aware that doing so requires specialized equipment and in-depth familiarity with the motor’s engine and components.

It may be too difficult of a task to do on your own if you have never worked on any engine before. Then it would help if you usually took the lawnmower to a repair shop.

5. Problems With the Head Gasket

Problems With the Head Gasket
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Head gaskets are components installed between an engine’s cylinder head and block to prevent combustion from escaping. There will probably be a lot of smoke if the head gasket fails.

Though less often it occurs, it’s also more difficult to rectify. Aside from the apparent white smoke, additional signs of this issue include oil leaks, increased crankcase pressure, peculiar sounds, and so forth.


You’ll need a handbook if you want a comprehensive explanation of how to service the internal engine components.

Lawn mowers that emit white or blue smoke may need to be sent to a small engine technician if you don’t have extensive experience with such machines and have already ruled out other reasons.

Getting a professional opinion is the first step if you want to go through with a more extensive repair job.

Read More About: How To Make A Riding Lawn Mower Go Faster?

Recommendations For Blowing White Smoke

What should you do if your lawnmower produces a cloud of white smoke in the center of your yard? 

It’s conceivable that your computer has a more serious issue that can’t be solved without bringing in a specialist, but there are plenty of easy-to-fix potential sources of smoke.

However, before you rush in to fix it, inspect it thoroughly; the problem might be minor.

  • Stop using the lawnmower immediately and set it somewhere to rest before doing any more troubleshooting. After it has cooled down enough to do so safely, open the chassis’ top and have a look inside.
  • You must locate and inspect the air filter. Typically housed in a plastic housing at the engine’s top, it. If the air filter is dirty, it should be cleaned or replaced.
  • Ensure the oil is in the lawn mower. It comprises the grade, the kind, and the tank level. If the oil level is low or you’ve accidentally put in the incorrect oil, try switching it out.
  • The engine may spill and smoke if the cut angle is more than 15 degrees; therefore, double-check your work.


What Happens If I Overfill the Lawnmower’s Oil Capacity?

If you accidentally fill your lawnmower’s oil tank with too much oil, it will likely start to emit white smoke as soon as you switch it on. The reason for this is that if there is too much oil, it will not be able to flow to where it is needed and will instead coat the exterior of the hot engine block, causing it to catch fire.

To what extent may a lawnmower explode?

In summary, under some circumstances, an explosion is possible in a lawn mower. While white smoke or any other color from a lawn mower does not always indicate an impending eruption, it is crucial not to dismiss the warning signals when they present themselves.

What causes white smoke from exhaust?

White, billowing smoke from the tailpipe might indicate a problem with your vehicle’s exhaust system. Three common issues: a blown head gasket, a cracked engine block, or a damaged cylinder frequently caused this thick smoke.

What happens if I overfill the oil in my lawn mower?

If you put too much engine oil into the vehicle by mistake, you will need to reduce it until it is at the correct level. To avoid injury, you should disconnect the spark plug wire first. Mower engine oil may be drained in several different ways.

Can too much fuel causes white smoke?

Without getting too scientific, injectors might leak or become stuck in the open position, which prevents fuel from entering the combustion chamber. There’s been a buildup of excess gasoline in the engine, which must be burned off and released. You may notice this as a greyish or whiteish plume coming from the tailpipe.


More concerning to your lawnmower’s safety is blue or black smoke. Although white smoke is cause for alarm, it is typically a simple problem to solve.

To get rid of white smoke, you need to address the underlying cause and let the engine run until the problem disappears.

Keep in mind that, for a time after being turned on, a brand-new lawnmower will produce white smoke while it adjusts to its environment. Don’t be frightened if you come across this on your first pass with your new mower.

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