Why is My Lawn Mower Smoking?

Smoke coming out of your lawnmower is a serious matter, but you don’t have to worry because the fix exists. Find the reason behind this unwanted smog.

White or blue smoke means oil is also burning along with fuel. It’s moving in the wrong direction, maybe towards the crankcase or anywhere else on the engine. Similarly, black smoke means there is too much fuel, but no air.

Overall, lawnmower emitting smoke is not a major problem, but if it continues to do, then you might have spent some time on the extensive repair.

Black smoke? Check The Air Filter


Air Filter

Your lawnmower is emitting black smoke probably because the ratio of gasoline to air is too to handle by its engine. In other words, the machine’s gasoline intake is higher than average.

As the amount of air is less, the combustion process never gets complete leaving some unburnt fuel that converts into smoke.

Another common causes of grey or black fumes is an exhausted filter. So, take the filter out, clean and reattach. You can use soap and water as the washing agent. If the filter is too old, then replace it with a new one.

If you still notice black fumes from the lawnmower, then it’s time to adjust its carburetor. You simply need to turn a screw to adjust the component. However, we recommend you to read the provided instructions manual to find the right settings.

White smoke? It Might Be Temporary


lawn mower smoke

Have you tipped over the mower to clean its blades? Or you recently serviced it or refueled its tank? Tipped mower is one of the major causes because it allows the oil to enter its cylinder.

So, when you start the machine, it starts burning the oil and converts your lawn into a cheap disco. So, let the mower run without any cutting load and the white smoke might leave you alone.

If you have a petrol lawnmower with a 2-stroke engine, then the wrong oil and gas proportion could the reason. Most of the machine has a proportion of 40:1 or 50:1. If the amount of oil is high, it will result in white smoke.

It might hurt the engine. If you need to eliminate the white smoke, then the only solution is to change its fuel. Some of the experts state that too much oil cannot harm an engine, which is wrong.

At times new mowers emit white vapor because of the fuel left by its manufacturer or retailer. So, you need to worry about any repairs. Let the engine run and it will automatically burn the fuel to stop the smoke.

Excess Of Blue Or White Smoke Is A Serious Trouble


If the white or blue smoke is not stopping even after you wait for a while, then there are chances that the oil has made way to the combustion chamber. If it’s the primary reason, then the engine might come to halt.

A leak in its breathing tube might be the primary cause. Such a rupture allows air to enter from the combustion box to the exhaust. Blown head gasket could another reason. In such cases, you need to consult a professional; especially if you are a newcomer.

Common Reasons For White or Blue Smoke From A Lawnmower


We were discussing some of the causes that indicate burning oil. So, let’s summarize all of them together. In case you notice any fumes coming out of your mower, it will work as a quick checklist.

  • Mowing on slopes greater than 15 degrees of angle
  • Punctured breathing tube
  • Air leak in the crankcase
  • Head gasket is not working
  • Exhausted cylinder
  • Tilting of the mower to clean the blades or for any other reason
  • Oil more than the engine’s capacity
  • Interruption in the breather tube

Find A Service Center.


Always read the instructions manual before performing any of the above-mentioned steps. It’s very important to follow the guidelines, otherwise, you might void the warranty or harm the machine. The manual will also let you know about the safety measures, which will help you to avoid any physical injuries.

In case none of the above steps can correct the white, blue or black smoke, then the mower might need some serious repair. Because it could an air leak, probably in its crankshaft (the cast iron or aluminum made housing that protects the internal moving components of an engine).

The smoke might mean that some of the engine’s internal components need replacement. If the black smoke is not leaving a mower, even after filter cleaning and carburetor replacement, then the machine might need some mechanical makeover.

If you need to contact a professional to repair the mower, check if it’s under warranty. If the machine is under warranty, then you can simply call the manufacturers or locate a nearby service center.

You can also refer to their website for assistance as well as find a nearby outlet wherein you can take the mower or call someone to your house. In case the mower is not under warranty, then any of the reputable technician shops can take care of your machine.

If problem continues you might think to buy a new lawn mower. If you want more convenient mower then I’d suggest to have a electric lawn mower. You can also ask any nearby expert to decide what kind of lawn mower will be suitable for you.

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