Lawn Mower White Smoke Then Dies: How to Fix it?

(Last Updated On: August 19, 2022)

If you own a lawnmower, then chances are at some point you will experience smoke coming from it. While this experience isn’t a guaranteed one, more often than not, lawn mowers produce white smoke.

There is no need to panic as most times, lawn mower white smokes mean that your mower needs a little time out. There are various ways to handle the white smoke issue. This article provides you with the necessary information you need to fix your lawn mower and get it back on your lawn in no time.

What Causes Lawn Mower White Smoke?

There are plenty of reasons why lawn mower blows white smoke and dies after few minutes and smokes continuously from their exhaust. Some of them are included:

  • A worn-out engine
  • Overfilled oil
  • Failure or blown head gasket
  • Tipped mower

Tipped Mower

The reason outlined above but the most common reason why your lawn mower could be blowing white smoke. However, a tipped mower is, in most cases, the reason why your lawn mower could be producing fumes. You may have tipped your mower to unclog the chute, change the blades, or clean out the deck.

Another cause for lawn mower smoking would be using your mower on a very steep surface. Both of these scenarios may cause the cylinder to fill up with oil. Once your cylinder fills up, restarting the mower causes the oil to burn, making your mower a chimney.

Fixing this issue is simple. Clear the mower off any oil and let it idle for a while. Allowing it to idle enables the lawnmower engine to rest, and the smoke will eventually clear itself out. If you are unaware of the correct way to tip over your mower, you can always check in your manual. It is also advisable to avoid surfaces that are steeper than a 15-degree angle.

Overfilled Oil Reservoir

If you want your mower to last longer, then engine oil should be your go-to. Engine oil sees your mower running smoothly and efficiently. Oil change regularly is a part of the maintenance of the mower. However, it is always advisable to know the right amount to put in and the fuel mixture ratio.

Overfilled Oil Reservoir

Putting in less than the required amount can be a disaster while putting in excess can also cause you problems. The former causes friction due to a lack of enough lubrication. The latter causes the oil to enter the cylinder and causes burning along with the fuel.

Too much oil in the lawn mower also poses the risk of an oil leak, which isn’t good news. Additionally, excess oil can also result in the crankset getting damaged, thus hindering its motion. Overfilling the engine with oil isn’t as bad as underfilling it since, as mentioned above, underfilling causes a lot of friction.

The way to fix this issue is to refer to the guide while refilling your engine oil to know the exact amount needed to avoid overfilling. Before that, you need to remove the dipstick cap carefully and reinsert it after doing the task. Most lawn mowers usually require not more than 20 ounces of oil – Use a dipstick to measure the oil.

After getting to ¾ of the recommended quantity, add small amounts of the engine oil until you get to the quantity required. If you have put in excess oil, then the only thing to do is to drain the excess. It is, however, essential to note that using the wrong grade of oil can also cause white smoke or, in other cases, blue smoke.

Refer to the manual to be sure of the exact lawn mower engine oil the manufacturer recommends to avoid the bluish-white fumes. If the mower is producing black smoke, then this means that there is a lot of air in the fuel.

Most times, a mower with a dirty air filter produces black smoke. This scenario is, however, a simple one to fix as you need to remove the filter and clean it out. To ensure the filter is clean, it is advisable to use water and soap. Another alternative would be to replace the filter with a new one. By doing all these jobs you should check and prevent air leak from any possible way.

A Damaged Lawn Mower Head Gasket

The reasons so far outlined don’t require you to be worried about the condition of your mower. However, a damaged head gasket is something to worry about. A head gasket is a metal used to seal the cylinder. It is fitted to close the combustion chamber.

Damaged Head Gasket

A puffing noise and a high crankcase pressure are usually an indication of a head gasket failure in addition to the white fumes. A faulty head gasket means that there is no seal on the cylinder, and therefore oil gets sucked into the combustion chamber. As a result smoking lawn mower is common at this stage.

As the engine oil starts getting into the cylinder, it can cause burning hence producing white smoke. If a lot of oil rushes to the cylinder, then the engine block may fail altogether. The fix is usually to replace the gasket with a new one.

Gaskets aren’t repairable, and once damaged, they need to get replaced. If you have no previous experience with small engines, then it is advisable to call an expert to fix it for you

A Failed Carburetor

In case you’ve adjusted or fixed all the above, and there is still smoke coming from your mower, then you would need to adjust the carburetor. Changing it ensures there is a much leaner fuel to air ratio. A gas smell is a sure indication that your carburetor is damaged.

Before adjusting, always consult with your manual to be able to identify which screws should be used for the process. If you are sure that the carburetor is damaged, then replacing it may be the best alternative for your lawn mowers.

In Summary: How do I fix white smoke from my lawn mower

  1. If you are overfilling the oil, be sure to check your owner’s manual to find out how much oil is needed for your engine size and do not exceed that amount. Also, make sure you are regularly checking the oil level so that you can avoid this issue in the future.
  2. If piston rings are worn, they will need to be replaced by a qualified technician.
  3. If the head gasket is damaged or blown, it may need to be replaced.

Related Queries: lawn mower white smoke problems & solving

Why does a lawn mower smoke after being laid on its muffler side?

The most common reason is that the oil has drained from the engine onto the hot muffler, causing the smoke. Other potential causes include a clogged air filter or spark plug, incorrect fuel mixture, or water in the gas.
If your lawn mower begins smoking after being laid on its side, check the oil level and add more if necessary. You may also need to clean or replace the air filter and/or spark plug. If you suspect that water has gotten into the gas tank, drain it out and refill it with fresh gasoline.

Why does my lawnmower give a huge white puff of smoke when it slightly tilts?

One possibility is that the oil in the mower’s engine is overfull. When the engine tilts, the oil can start to leak into the combustion chamber and cause a smoky mess. Another reason could be that you are using too much oil in your fuel mix. If you are using more than 20% oil in your gas, it can create a lot of smoke as well.


There’s only so much you can do. If all the above steps do not fix the smoke situation, then that could indicate a more serious underlying mechanical issue. Continuous blue or white smoke could mean that some components of your engine or mower are entirely worn out.

Similarly, persistent black smoke could indicate critical mechanical issues. All these issues would require you to get a professional to intervene. If your mower is on warranty, you can get it fixed by your manufacturer. If not, you can visit a reputable repair shop and get it checked out.

Reference and Data Source:

  1. Head Gasket:
  2. Engine Oil Over Filled Cause:
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Mitchel Shawn was a Co-worker and Engineer of a Gardening Tool manufacturing company since 2013 and a passionate researcher on Machinery goods. Picking the right tools for your work-station and making life easier is an untold helping journey by SHAWN. With this Reviewer Guides Blog, you'll definitely get help in revealing the accurate product spec which actually helps in real life works.