How to Stop a Lawn Mower from Smoking?

Truth be told, lawn mowers are probably the sole gardener’s equipment that offer greatest return on investment. They are worth their weight in gold. Sadly, just like any other machinery, they can breakdown. Failure of a lawn mower to start and smoking are the most common signs of underlying engine problems.

At some point, every gardener experiences emission of an odd colored smoke from their mower’s exhaust. Smoke is a sure sign that all is not well with the mower’s engine. Luckily, it is not a very serious problem. However, if left untreated it can become a big issue and ultimately cost you money on repairs.

Lawn mowers smoke for varied reasons, many of which don’t necessitate professional expertise. There are different colors of lawn mower smoke. A mower can identify the reasons for a smoking lawn mower. You do this by gauging the color of its smoke. Ensure you then fix it before further damage occurs. This post will help you identify and stop a lawn mower from smoking, but first.

Common Causes of a Lawn Mower Smoke

Mostly, this is caused by oil spillage. You may have changed the oil then spilled some or exceeded the recommended oil level. This is how to correctly do your mower’s engine oil change.

Additionally, you could have turned the mower upside down during maintenance, storage or any other reason. Mowing on a slope could also have been the source of the oil spillage. Other causes include:

  • Overfilling the crankcase with oil
  • An obstruction in the breather tube that’s found behind the air filter
  • Damaged crankcase breather
  • Blown head gasket
  • Damaged cylinder and/or rings
  • Use of wrong engine oil grades
  • Tilting the engine at greater than a 15 degree angle
  • Crankcase air leak
  • Turning/tilting the engine on its side for storage, oil change or any other reason

Common Causes of a Lawn Mower Smoke

What to do before Trying to Stop a Lawn Mower from Smoking

Know about the configurations of its internal combustion engine. Lawn mower may have similar basic parts but their configuration differs depending on the model.

If you are not sure with how to access specific components of the mower’s engine, always start by consulting the user’s manual. This won’t hurt.

What to do before Trying to Stop a Lawn Mower from Smoking

How to Stop a Lawn Mower from Smoking?

A smoking lawn mower will emit a black, white or blue smoke. Each of these colored emissions passes a different message. Here is what they mean and what to do in order to address the issue without necessarily consulting a professional mechanic.

1. Emission of Black Smoke

This depicts a problem in the carburetor and fuel system. It results from rich fuel-to-air mixture-meaning there’s more gasoline in the mix than it’s required.

Mower’s black smoke comes as a result of burning of more fuel than air. This in itself is caused by either clogged air filters, un-tuned or dirty carburetor that requires cleaning .

Emission of Black Smoke

Procedure to Stop Mower’s Black Smoke

  • Locate the air filters. They’re quite easy to unfix, diagnose and re-fix.
  • Unfix the air filters then clean them. Some DIYers do this using their mouths to blow away any dirt on the air filters. If you have air compressor, the better, it does a more thorough cleaning. If they’re clogged, replace them. Luckily, they’re so cheap.

Procedure to Stop Mower’s Black Smoke

  • Re-fix the air filters and start the lawn mower again. If the emission of the black smoke persists, proceed to the next step.
  • Adjust the carburetor by twisting the screw. The adjustment is done in order to make it produce a leaner and more balanced fuel-to-air mixture. Though this adjustment is quite simple, you may need to refer to user’s manual for insights on that specific mower and carburetor.

Ideally, the above steps should stop your lawn mower from producing the black smoke. If they don’t fix the problem, it means there could be something more complex. In such a case, we would advice you take it for expert diagnosis.

2. Emission of Blue or White Smoke

This kind of mower’s smoke is results from by burning of excess oil. Yes, excess oil is as bad as with too much gas. In most occasions, the cause of this smoke is quite simple and easy to fix.

Just like other machinery engines, mowers’ engines are made with specific tolerance to angles of operation. Tilting it can let some of its oil leak out. When this happens, the oil burns off thus producing the blue or white smoke.

Emission of Blue or White Smoke

Apart from tilting, overfill of oil reservoir or usage of wrong engine oil grade could also be cause of the white or blue smoke. This is how you check the oil level.

  • Open the dipstick cap and remove the stick
  • Wipe the dipstick with a piece of cloth/rag.
  • Put it back to the oil reservoir.
  • Remove the stick again and confirm that the oil level is in the right ‘fill’ level as visible on the stick. If it’s in excess, consult your user’s manual for instructions on how to drain and refill the oil reservoir to the correct level.

How to Stop Mower’s Blue or White Smoke

As alluded to herein above, this kind of smoke is normally caused by spillage of engine oil upon tilting or oil overfills. Although it looks quite disconcerting, it’s harmless. To stop the smoking, let the engine continue running to burn off the excess.

Turning off the engine won’t help-the smoke emission will still continue once you turn it on again. Luckily, it doesn’t last long.

If this kind of smoking occurs frequently, it could be a sign of something more serious. Check the crankcase. Check if there are any air leaks. Presence of air leaks makes there be more air into the crankcase than required. This cause higher oil mist than its breather can handle thus causing it be burnt off.

In case there are no leaks and your mower continues smoking, it now could be an issue of a blown head gasket, damaged crankcase breather, damaged rings or cylinder. Unfortunately, this will require you to seek the service of a skilled mechanic.

How to Stop Mower’s Blue or White Smoke

Tips on How to Stop a Lawn Mower from Smoking

  • Monitor the quantity of fuel or oil in the engine. Overfilling will cause the emission of smoke.
  • Endeavor to always keep the mower on a balanced level ground. This reduces the chances of any possible tilt and spillage of oil.
  • Always use the right engine oil grade.
  • Ensure there are no air leaks on the crankshaft.
  • Frequently check the head gasket, rings and cylinder and ensure they’re in good shape.

Wrap Up

Hopefully, the guide on how to stop a lawn mower from smoking will come in handy and facilitate your mowing sessions. Evidently, when a lawn mower smoke it doesn’t mean it’s broken, could be it just need a little bit of ‘love’ and care.

Simply check the color of your mower’s smoke and employ your DIY prowess before taking it for repairs. This could be the difference between buying and fixing cheap air filters, renting a lawn mower or spending loads of cash on labor and spare parts. We hope you’re now well equipped to avoid engine oil problems and stop a lawn mower from smoking. Have an enjoyable time in the sun mowing and all the best.

About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

Join the discussion