How to Stop a Lawn Mower From Smoking?

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Let’s be honest – you have been thinking about mowing your lawn for quite a while. However, procrastinating hasn’t stopped your lawn from getting any messier, and it has become quite clear that you will have to mow the stubborn grass sooner than later.

The fateful day arrives and you’re finally going to do it. You’ve got your schedule fixed, and lawn mowing takes up a considerable portion of that tight schedule.

Consequently, you’ve made sure that the mower has enough gas to do the lawn and you’re all set. In short, you’re fully prepared.

Unfortunately, you weren’t prepared for the cloud of white smoke from the lawnmower that is threatening to envelop and suffocate you after you turn it on, ruining any possibility of getting your lawn mowed within the constraints of your well-planned schedule. Cutting grass manually is simply out of the question so there’s only one alternative left – fix your mower and stop it from smoking.

Types of Smoke and What They Mean

You may be surprised to learn that a lawn mower can emit smokes of certain shades depending on the trouble it is suffering from. The smoke can be black, white, blue or even a combination of them depending on the issue.

  • Lawn Mower Black Smoke
  • Lawn Mower White Smoke
  • Lawn Mower Blue Smoke
  • A Combination of Blue or White Smoke

Keep in mind that a little bit of smoke coming out of your mower does not necessarily mean that there is something seriously wrong with it, as it is a machine that burns fuel to run. As a result, you can expect it to leave a smoke trail every once in a while. However, if there is too much smoke, then there is reason for caution.

#1. Lawn Mower Black Smoke

Black smoke coming out of your precious $400 grass-cutting beast can be a worrying sight for most owners. There are numerous reasons for a lawnmower to start coughing up plumes of black vapour. Sometimes it’s just a dirty filter that can be either replaced or cleaned. Other times it’s the fault of the fuel and air mixture.

When the fuel in your mower’s tank doesn’t get sufficient air to burn, it burns up too much fuel and turns into black smoke. Another reason for the ghastly black smoke can be leaking oil which might have contaminated your cylinder. Fixing this issue is not that complicated. All you have to do is follow these simple steps.

How to Tackle this Problem

If your filter is the main issue then you can simply choose to clean or change it. Filters are made from materials like paper or foam. It is recommended that you replace faulty paper filters, as cleaning them can be futile.

If you have a foam filter, then you can clean it with soapy water. Make sure to dry the filter completely and coat it in engine oil before putting it back into the mower.

If the filter was not your problem then perhaps the fuel is. Try aiming for a cleaner fuel mixture by making a few adjustments to the carburetor.

This will ease the strain on the mower’s engine and solve your smoke problem. It is recommended that you consult the owner’s manual before trying to fix this issue.

#2. Lawn Mower White Smoke

No, the new pope has not been chosen if you’re seeing white smoke coming out of your garden. It is just your faulty mower. White smoke coming out of your lawn mower often means that the engine is merely burning fuel.

If that’s the case, then letting the mower run idle for a few moments should stop the white smoke altogether. Reasons for white smoke are usually spilt oil on the housing or the combustion chamber, filling the tank with excessive fuel or just oil residues left in the tank.

How to Tackle this Problem

The easiest way to tackle white smoke is to let your mower run until it stops blowing smoke. Brand new lawnmowers will always blow out some white smoke when you start them for the first time because of the oil residues left in its tank by its manufacturers.

If the problem persists, then it is possible that you may have unknowingly filled the tank with too much fuel.

People who are using a lawnmower with a two-stroke engine should note that the correct fuel proportion they should be using is somewhere around 40-1 and 50-1.

You should also note that excess fuel will not do any harm to the mower. However,  the fuel will have to be changed to entirely solve the white smoke problem.

Also Read: How to Replace Pull Cord on Lawn Mower?

#3. Lawn Mower Blue Smoke

It is weird how your lawn mower can communicate with you in such colorful manners! Blue smoke is perhaps the least alarming color of vapor that can come out of your mower.

It usually means that oil has leaked into certain areas of the mower where it shouldn’t have been. Blue smoke can also appear when you accidentally pump too much oil into your machine.

How to Tackle this Problem

Remedies for the blue smoke problem are the same as the white smoke ones. Letting the mower run for a while can help alleviate the problem. You can also prevent this from ever happening by adjusting your spark plug tilter so that it is always pointing up.

Doing this will prevent oil spills in the future if you have to mow the grass on uneven terrain,  such as a hill.

#4. A Combination of Blue or White Smoke

Granted that blue smoke alone was not a serious issue but a combination of blue and white smoke or excess smoke coming out of your lawn mower can be a serious issue. If that ever happens, then it is possible that your mower has a few worn-out seals, which are letting oil seep into the combustion chamber.

Under these circumstances, your mower will smoke continuously and the engine might sputter and stop abruptly. Reasons for this can be anything from a torn gasket to a ruptured breathing tube.

How to Tackle this Problem

Under these circumstances, mechanical repairs are needed. If you know a thing or two about doing such repairs then you should be able to fix your mower with ease.

Otherwise, it is advised to let a professional do the fixing, as an amateur might end up damaging the mower further or hamper its lifecycle.

You should also not ignore this problem and run a crippled mower to do your chores, as this will only do more damage to your machine and make matters worse.

You May Also Read: What Kind of Oil Goes in a Lawn Mower?

What Causes a Lawn Mower to Start Smoking Like a Chimney?

What you should immediately do when you see smoke is to turn the mower off. What you should not do is panic. Smoke coming from your mower does not necessarily mean there is something seriously wrong with your machine.

However, delaying fixing it is not going to solve anything either, as there is a high possibility that the problem will not go away on its own and further neglect can do irreparable damage to your mower.

In fact, sometimes the solution can even be as simple as replacing minor parts. All you have to do is observe the color of the smoke and notice where they are emitting from.

That can tell you a lot about the problems that your lawnmower is having and help you fix them at a moment’s notice without seeking professional help.

Lawn Mower From Smoking


Seeing smoke coming out of your lawn mower can be distressing. Hopefully, the remedies and the preventive measures that we have provided will help you out if you ever find yourself in such a situation.

Maintenance of your machines is also something that is required to help extend their usefulness and life-cycle. A small problem and lead to a series of problems that can kill your mower entirely.

Always remember to keep your fuel proportion in check, clean your filters regularly, watch out for the little leaks and get them patched up. Doing all this will make sure your lawn mower stays in perfect shape for years to come.

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