Lawn Mower Smoking White

Some people are asking us about lawn mower smoking white if this is a sign of a serious lawn mower problem or an easy fix that can be easily resolved. Well, we should tell you that when you see smokes coming out of the carburetor or from any part of the engine, this calls for intense observation. The trouble could be simple as an oil spill or it could be serious like a broken piston ring. Do note that lawn mower smokes do also vary in color. Other than the white smoke, there is also the blue and the black smoke which can indicate different problems. lawn mower smoking white

So let’s get to the point, when a white smoke from lawn mower comes out like thin clouds, this could be a symptom of simple issues like an overfilling of oil into the cylinder which got heated up and got burned when the engine got hot. It could also indicate more serious problems with the engine or just dirt inside your engine or in the carburetor. If you are not aware, there are two types of lawn mower engines and these are the 2-strokes and the 4-strokes.

The 2-stroke lawn mowers mix up their oil along with the gasoline in one cylinder while the 4-strokes have separate compartments for the gasoline and oil. Now, why we are telling you about dirt and oil is because these are some of the most common causal problems of lawn mowers producing smoke. But to harder issues, it could be the parts involved that are mainly inside the cylinder or with the carburetor. We will discuss more of these below but let us answer one common question that many homeowners also commonly ask and this is about lawn mower blue smoke

Lawn Mower Blowing Blue Smoke

Blue or white smoke is usually caused by the burning of excess oil and most often this is just a simple issue that can be easily fixed. What usually happens is that when the engine is tilted or turned at a sharp angle, this causes the oil to spill or leak out into the cylinder. When this oil gets burned off by the hot engine, this makes the lawn mower blue smoke to appear. So the best thing that you could do is to let the engine run and wait till the spilled oil gets burned up and the smoke disappears.

White or blue smoke can also occur due to the overfilling of oil in the reservoir so the same solution must also be done – let it burn out or drain some of it. However, there could also be other causes for lawn mower blowing blue smoke and this can happen on the crankcase. The crankcase of the 2-stroke engine is where the compression and combustion of gas and fuel mixture happens. So imagine as the piston moves fast up and down to burn the oil and gas mixture inside and if there’s a leak somewhere and the air gets sucked in, this causes a higher oil mist which the crankcase breather could not handle. Thus, the oil gets burned out along with the unnecessary oxygen causing the lawn mower to blow out smoke.    

Check the cylinder carefully and look for cracks or loose joints. If you cannot detect any leak on the cylinder or in the crankcase and the blue or white smoke continues to appear even after a few minutes of engine running, again, the problem can be caused by other causes. It could be a blown gasket, a malfunctioning crankcase breather, or a worn piston ring or cylinder. If you’re not a mechanic, better bring your machine to the shop for inspection and repair.

White Smoke From Lawn Mower

As we have mentioned, there are also possible causes of white smoke from lawn mower other than the spilling of oil to the cylinder. So we now identify some of these to give you some hints on how to inspect and even do some quick troubleshooting tricks which could work on your machine and save you some money for repair.Lawn mower blowing blue smoke

Lawn mower white smoke

 Lawn mowers have the full oil capacity of over half a liter. But this does not mean you have to completely  fill it up otherwise you could damage the engine by splashing oil where it’s not needed. lawn mower smoking white

To pour just enough oil on the lawn mower, totally drain the dirty or old oil from the cylinder then pour the fresh oil in small increments while dipping the dipstick from time to time to check the level. To know the right oil level, at the end of the dipstick is a line and more rough lines under it. The uppermost line means full so DO NOT PASS this line. Also, don’t screw in the dipstick on the cylinder when checking the oil.

Riding mower blowing

If your lawnmower is a riding mower, usually the white smoke tells you about too much oil in the reservoir or it could be a problem in the carburetor. A blown head gasket is also one possible cause. Refer to your user’s manual for troubleshooting broken gaskets or let a professional check your machine. You can also call your machine’s manufacturer especially if it’s under warranty for advice or free checkup. 

Gas mixes with the

When you overfill your oil reservoir and you run the engine and there comes the smoke with a smell of gas, the most possible cause is a problem in the carburetor seal. In this case, turn off the engine and check the carburetor for leaks or dirt. A broken gasket in the carburetor should be replaced. Dirt in the carburetor can be fixed using a carburetor cleaner. If the smoke problem still occurs, check the manual or call the machine’s manufacturer. 

Lawn mower smoking

 If there’s the white smoke from the lawn mower and the machine periodically dies this can be possibly caused by the oil spilling into the carburetor and has lodged inside the gas feed jet. Try repeatedly starting and revving the engine to clear up the blockage for a few minutes. If the engine still dies, clean the carburetor as the last option. 

To do this, remove the spark plug first and tilt the engine several times towards the direction of the oil reservoir to avoid spilling the oil on the cylinder. Spray the spark plug socket with a carburetor cleaner including the tip of the spark plug and wipe the plug seat with a clean cloth including the tips of the spark plug. Remove the carburetor cup and check for any dirt. To be sure that there’s no oil in the carburetor, spray the carburetor valves with a carburetor cleaner.lawn mower blowing smoke

Accidentally spilling oil

If your lawn mower is a 4-stroke, this is the usual problem and smoke may come out from the cylinder. To fix lawn mower white smoke due to gas-oil mix-up, you have to fully drain the gas out from the reservoir and refill with fresh gas and run the engine until all the smoke goes out.

Failure of the

Lawn mower head gaskets are made of metal and graphite materials but they can also get damaged due to overuse and heating up past recommended temperature. Its purpose is to seal off the combustion chamber so you can find it fitted between the cylinder head of the engine and the cylinder block.This Can Cause Lawn Mower Smoking White.

 Head gaskets can be cleaned  using a carburetor cleaner after disassembling it from the cylinder. But if it is already worn out, you need to replace it with a new one. 

Black smoke coming out from the

 The usual cause is a problem on the carburetor or in the fuel injection system which can be due to fuel-to-air mixture that becomes too rich for the cylinder to burn. This means that you have put gasoline more than its proper ratio with the oil. lawn mower blowing smoke

The smoke problem begins when the carburetor is not properly tuned up or the air filter gets clogged up which makes the clean air unable to provide enough air for the cylinder to burn fuel properly. In this scenario, you will have to check the air filter first before fixing the carburetor. If the air filter is still new, this will only need basic cleaning. Lawn mower blowing blue smoke

There are 3 general types of air filters for lawn mowers: the foam type, paper and dual elements. The foam type is easy to clean with detergent and water. The paper air filter needs to be replaced or try cleaning it up with compressed air. The dual-element consists of foam and paper. The foam can be cleaned but the paper needs to be replaced or try compressed air.lawn mower smoking white

For the carburetor valves  spray them with a carburetor cleaner and wait till the liquid settles down. Refix the valve and restart your mower.

Black smoke is still coming out after cleaning the air filter and carburetor.

Try adjusting the carburetor until the cylinder produces a leaner fuel-to-air mixture. This can be done by turning a screw. Refer to your lawn mower’s user manual guides.      

Lawn Mower White Smoke

Do issues in the spark plug can make a lawn mower smoking white? It surely can. The role of the spark plug is to create spark so that the air-fuel mixture inside the cylinder will ignite and create an internal explosion and combustion that will convert into power. Spark plugs create an electrical spark across its two leads and this electricity is what makes the compressed air-fuel mixture to burn.  lawn mower blue smoke

But how does white smoke from lawn mower  be caused by a problem with the spark plug? This means that there could only be two causes and it’s either due to fuel issues (incomplete combustion of fuel) or carbon build-up. For the fuel problem, when there is a rich mixture of air and fuel or a mixture of oil and fuel, some of these mixtures won’t be able to get burned in the combustion chamber so you have to adjust a screw on the carburetor to fine-tune the fuel flow. 

For the carbon deposit issue, when there is improper combustion of the mixture on the cylinder, the spark plug can accumulate carbon deposit or oil residue on its electrode which makes it unable to produce enough spark. So the only solution to this is adjusting the fuel flow and removing the spark plug and spraying the plug’s seat and the electrode with a carburetor cleaner. Wipe off the excess cleaning liquid with a clean cloth. So always check the spark plug for dirt like carbon and maintain it by cleaning it with a carburetor cleaner. If that doesn’t fix your problem you might need to replace your spark plug.


Now that you have learned what could be the causes for lawn mower smoking white you may want to do your troubleshooting skills with your lawn mowers whenever a smoking problem arises. Remember that smoke on engines can occur due to a lot of factors. But the main problem is usually due to oil spillage and incomplete combustion of fuel. However, you must be aware of the smoke coming out of your engine if it’s black or blue because as we have discussed, these symptoms could indicate more serious problems. Lawn Mower Oil Type

To avoid having problems with your machine, try to have a regular maintenance task like changing the oil regularly and always maintain a good oil level, cleaning the air filter every after use, checking the spark plug for carbon or oil deposits and clean the external part of the engine by spraying it with water mixed with detergent to take out accumulated dirt. 

Clean also the underside of your lawn mower which includes the blade and the mowing deck. When too much dirt solidifies and is not removed, this makes the machine work harder and make it inefficient. 

Leave a Comment

Your email address will not be published. Required fields are marked *