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Why Do Lawnmowers Smoke and Ways To Stop It

Suppose your lawnmower starts smoking all of a sudden while mowing your garden then you should be aware that there is something wrong with your mower. Most of the time the smoke comes out of the lawn mower’s deck. It may start coming out right after pulling the cord or it may also occur after sometimes you start lawn mowing. In most cases it is not related to any serious problem but it will not go away on its own and can lead to another severe malfunction. You need to know why lawnmowers smoke and how to fix this issue. So, without any further delay let’s get straight into our topic and how can you solve this problem by reading below the ways to stop the smoke.

A photo of smoking lawn mower

What Type of Smoke Does a Lawn Mower Emit?

As we have talked about why lawnmowers smoke it is time to discuss the types of smokes you can see coming out of a lawnmower. Either black, blue, or white-colored smoke comes out of the lawnmower. The smoke color depends on the cause of smoking.

Reason Why your lawn mower smokes

It is time to answer your question: why do lawnmowers finally smoke? We will talk about all three colors of smoke and their reasons.

  1. Black Smoke: If your lawnmower emits black smoke the carburetor is not working correctly. When the gasoline to air ratio is not perfect 32:1 black smoke will come out. A worn-out air filter or clogged one can even lead to black smoke coming out of your lawnmower.
  2. White Smoke: White smoke is the most common color of smoke from a lawnmower. In most cases an overfilled reservoir causes the smoke and you need to wait patiently for the excess oil to burn out. The spilling of oil which is another reason behind white smoke can occur when a lawnmower is used at more than a 15-degree angle. Air leaks, cracks in the crankcase, old rings and cylinders can also lead to this problem of smoking.
  3. Blue Smoke: Almost all the causes mentioned in the white smoke section can also cause blue smoke to come out including overfilling of oil in the tank or spilling oil and a few others. If you use oil unsuitable for your lawnmower it will also emit blue-colored smoke.

How Can I Solve the Smoking Problem?

There are some easy ways to stop smoke from the lawnmower.

1. Black Smoke: As the inadequate amount of airflow may cause it you need to inspect the air filter condition. If you find out that it is completely worn out you should change it immediately. There is also a possibility that some dirt might have stuck inside the air filter. Remove the clogging and restore the airflow to solve the problem. After replacing or removing the dirt from the air filter let the lawnmower run for a few minutes to see whether the issue has been resolved or not.

2. White Smoke: White smoke will be released chiefly when there is an extra amount of oil inside the lawnmower. Keep the lawn mower running till an excess amount of fuel burns out. If it keeps coming out even after 15 to 20 minutes then you have a more significant task in hand. The defect can be anywhere inside the lawn mower’s deck.

  • Start your inspection from the seal of the combustion chamber. If the seal is broken, fix it and the smoke will disappear.
  • If the problem lies in the crankcase you should look for any air leak. If you find a place where the air leaks secure the area.
  • Sometimes even the head gasket can also start to malfunction.

In that case you cannot do anything. Please seek professional help and do not use the lawnmower until repaired.

3. Blue Smoke: In most cases spilling oil in the carburetor or any other part of the lawnmower occurs when you use the electronic device on an inclined surface as an owner. Try to avoid uphill mowing and always read the user manual to know which is the ideal fuel for your lawnmower. If you have to do it then tilt the spark plug of your lawn mower before using it.

Precautions That You Can Take to Prevent the Lawn Mower’s Smoke

Safety measures to take in future to avoid smoking problems in Lawn Mowers:

After finding the root cause of the problem you can do the repair work all by yourself or take it to a mechanic. If you choose to fix it on your own you can easily find a solution on how to solve any one of the issues as mentioned earlier. This section will tell you some of the precautions you can take to avoid this problem. Moreover, you will stop wondering anymore why do lawnmowers smoke?

  • Check and replace the air filter to maintain adequate airflow inside the oil reservoir from time to time.
  • While pouring the oil in the lawnmower keep an eye on the oil level in the reservoir to avoid spilling. Change the oil from time to time to keep up the performance.
  • If the oil reaches way close to the engine, let the oil burn to prevent any harm to your appliance. This burning of excess oil will take not more than 20 minutes.
  • Any angle more than 15 degrees can lead to smoke coming out of the lawnmower. So, avoid mowing on slopes greater than 15 degrees.


A smoking lawnmower is a nightmare for any owner. As we have concluded the article we hope that you understand why lawnmowers smoke and ways to stop it you should be concerned about irrespective of the colour of the smoke. You can repair your lawnmower all on your own and if you cannot do so, you can seek professional help. So, please don’t leave this issue unattended as it can turn into something serious and can cause permanent damage to your lawnmower.

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