Lawn mower blowing smoke can be scary and make you wonder what made this happen.
Regardless of your mower model, it’s common to encounter engine problems such as mower blowing fire and others.
If you’ve been there, there’s nothing to worry about as we’ll walk you through the steps to follow when your lawn mower blows smoke.
From gas leaking into lawn mower mufflers to overfilled engine oil, lawn mowers pushing out smoke is a common thing to encounter.
Whatever the case, maybe, lawn mower blowing smoke is apparently not a good sign for your mower’s health.
However, the intensity and color of the smoke determine whether the problem is severe or not. If it’s blue smoke, the indication tells that the oil has been badly burnt or the fuel stale.
But black smoke is something more severe as it indicates that your mower needs refueling.
No matter what colour it is, a lawn mower pushing out smoke isn’t something you can neglect and let the mower rest to recover itself.
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When Does The Lawn Mower Start Blowing Smoke?
Most of the time, the lawn mower starts pushing out smoke when it’s powered up. This means any issues with the engine ultimately impact lawn mower health, requiring an immediate fix.
However, this small problem can become a more serious problem, leaving behind lasting damages if not treated immediately.
Let’s dive deeper into the common causes of why your lawn mower blows smoke.
Causes Of Lawn Mower Blowing Smoke
1. Black Smoke
A cloud of black smoke is a clear indication of engine malfunction in your mower, which results in the lawn tractor engine sputtering sound.
Usually, it happens because of an unexpected or unplanned mixture of fuel and air that causes mower blowing fire.
As a result, combustion ensues in the engine and causes smoke that can make you worry. In such cases, you might have experienced a lawn mower pushing out smoke.
The phenomenon is the same as burning a pile of leaves and storing them in a tight-fitting compost bin. This burning of oxygen causes fire and results in heavy smoke.
2. Dirty Air Filter
Another culprit of lawnmower pushing out smoke is possibly your mower’s dirty or damaged spark plug.
If you don’t know what the job of an air filter is, it is there to filter the gasoline air from dirt and debris before it enters the engine.
Most air filters are made from paper or form and are likely to get dirty or damaged too soon.
If the air filter doesn’t do its job correctly, the unfiltered air will ultimately cause the smoke to blow from the engine.
If that’s the case, all you have to do is clean the dirty air filter and put it back in its place. However, if the filter has been damaged or badly burnt due to any cause, it’s best to replace it with a new one.
As soon as this problem is treated, you’ll get your answer of the lawn mower blowing out smoke.
3. Dirty Carburetor
This is in continuation with the air filter solution. After you’ve carefully replaced the air filter, adjust the carburetor a little to allow the fuel to move all over the engine.
To do this, simply unscrew the engine, slightly adjust the carburetor from its original position and tighten the screws back.
Although this step is optional, it can prove in your favor in case the lawn mower burning oil white smoke problem doesn’t solve even after cleaning the air filter.
4. Oil Burning
Oil is what lubricates the engine and gives it the push to run. That’s what makes an overfilled engine become another most common cause of lawn mowers blowing out white smoke.
If your mower starts smoking, it won’t move; it’s probably because of the oil you left to burn. Either by mistake or intentionally, you might have spilled some oil while filling the tank or maintaining the mower.
Whatever the cause may be, this lawn mower leaking oil is the real culprit of your lawn mower burning oil white smoke.
When you turn the mower on, the oil makes its way to the combustion chamber and burns there, resulting in white smoke coming out of the lawn mower.
To treat this problem, replace the damaged head gasket to soak all the excess oil in the air filter.
In addition, it’ll also stop the oil from moving into the combustion chamber, which mostly results in lawn tractor engines sputtering sound.
5. Tripping Over The Mower
If you’re asking yourself the question, why is my lawn mower blowing smoke? The answer is the oil leakage into the mower.
For specific reasons, you might need to trip the mower on either side, such as for maintenance or fixing small lawn mower problems.
As you trip the mower, the oil moves to the cylinder, causing the mower to blowing fire and the burning oil white smoke starts. Therefore, it’s recommended not to lift the mower over a 15-degree incline, or the consequences can be severe.
6. Gas In The Oil
Lawn mowers pushing out smoke are also common to encounter in gasoline-powered lawn mowers. If overfilled engine oil white smoke isn’t an issue, then it’s probably the gas leaking into the lawn mower muffler.
It usually happens when the oil mixes with the gas and disturbs the carburetor. If you can sense this problem, it’s best to replace the oil in the mower and pour in the unfiltered, right-grade oil.
To handle this issue, simply change or replace the faulty carburetor.
How Do I Clean The Carburetor On My Lawnmower?
Our experts recommended this 5-step formula to clean the carburetor so you can get rid of the problem of my lawn mower blowing smoke.
- Remove
- Stripe
- Clean
- Rebuild
- Refit
Pro tip
To change the oil, replace the float needle, pour in the new oil, seal the carburetor and fit the fuel tap tightly.
Head Gasket Failure
A head gasket is a small handy part of a lawn mower mostly made up of graphite or metal. The job of a gasket is to seal the combustion chamber and avoid oil leaks because of overfilled engine oil white smoke.
If you can hear a lawn tractor engine sputtering sound because of a blocked crankcase breather, simply clean the pipe and replace the head gasket.
Once you’re done, check if your lawn mower is still leaking oil, burning oil white smoke. However, this is also the most common cause of electric lawn mower smoke, riding lawn mower smells burning, resulting in mower blowing fire.
In short, the blocked crankcase breather, once treated, will solve all the related problems from overfilled engine oil white smoke to gas leaking into the lawn mower buffer. However, the problem is more common in the two-stroke engine and OHV type (overhead valve types engine).
What does the color of smoke say?
The color of the smoke blowing from your lower tells how serious of a problem it is. Whether the mower starts moving then won’t move, or the lawn mower cuts out and smokes after startup, the issue remains the same.
In general, the smoke is of three colors: white, blue, and black. Once you can identify the color of smoke, it gets easier to treat the issue of lawn mowers blowing white smoke.
However, the difference in color is also because of the different lawn mower models and your lawn mower maintenance regimen.
If you’re unsure of the color of the smoke, it’s best to refer to the user manual to know the root cause of the problem. Here is a list of solutions you can follow to treat the exact cause of a lawn mower burning oil white smoke.
12 Quick Fixes For A Lawn Mower Blowing Smoke
1. Don’t mow on a slope greater than 15 degrees which result in oil spillage as you tip the mower on one side.
2. Restart the mower and let it rest for some minutes till all the oil is burnt off.
3. Do regular lawn mower maintenance and seal all the worn-out areas to prevent oil leaks that could possibly cause free.
4. Seal the lubrication system in your mower so there’s no overflow over the oil or leak of excess oil.
5. Clean and replace dirty, clogged, damaged, and burnt air filters.
6. Clean the carburetor and adjust it properly on the mower.
7. Regularly check the level, grade, and type of oil and refill if needed.
8. Run the mower for at least 5 minutes to burn the oil spilled over the surface.
9. Avoid overfilling the crankcase with oil.
10. Seal the crankcase air leak
11. Repair or replace the blown head gasket.
12. When changing the oil, always tilt the mower in a way that the spark plug faces upward.
Why Is My Electric Lawn Mower Smoking?
Due to heavy batteries and powerful engines, electric lawn mowers are likely to encounter smoke-blowing problems.
Before knowing what caused this problem, unplug the mower, investigate it a bit, and follow any of the aforementioned solutions.
Most of the time, it’s either the burning motor or damaged belt that fails to drive the blades, resulting in the lawn mowers pushing out smoke.
Other possible causes can be dirty air filters, head gasket failure, leaking carburetor, overfilled engine, wrong oil type.
Why Is My Lawn Mower Blowing Out White Smoke?
Lawn mowers blowing out White Smoke is more common to see than blue or black smoke, which is a severe problem. However, white smoke indicates that the burning oil has possibly entered the combustion chamber.
The most common cause of this problem is overfilled engine burning oil. When this happens, simply leave the mower to run for 10-15 minutes until all the oil is burnt out and released in the form of burning oil white smoke.
After this, restart the mower and it will all be fine to mow.
What happens when you put too much oil in a lawn mower?
Most homeowners don’t realize the harmful effects of adding too much oil into their mower. Not only does it disturb the mower engine, but it also causes overfilled engine oil white smoke.
A good rule of thumb is to only fill the tank to the level you can easily seal the oil cap.
Overfilling oil also results in seal damage, blown gaskets, or becoming hydro-locked. Whatever the cause, the excess oil is then burned off, and the primary reason for the lawn mower blowing white smoke.
Why Did My Lawn Mower Smoke When I First Started It?
Most lawn mowers smoke when they’re powered up as the excess oil in the engine is left to burn. Therefore, when the engine gets power, it first removes the extra oil that has been there due to overfilled engine oil white smoke.
If this happens, simply leave the mower for 5-10 mins so it can burn all the excess oil and be back to normal.
What Does Black Lawn Mower Smoke Indicate?
If your lawn mower is blowing black smoke, it’s surely because of the damaged carburetor.
The job of the carburetor in the mower is to regulate the fraction of gasoline entering the air mixture. When it fails to do that, the unfiltered gasoline enters the engine and passes through the dirty or clogged air filter.
As a result, your lawn mower starts pushing out smoke, which can be solved by the suggestions mentioned here.
How Do You Remove Oil From Lawn Mower Exhaust?
Usually, oil moves in the lawn mower exhaust due to overfilled engine, dirty air filter, carburetor, or worn-out cracks. Therefore, the easiest way to remove oil from the lawn mower exhaust is by squeezing the excess oil from the engine.
This happens because of overfilled engine oil, so it’s best to seal the worn-out valves while maintaining the mower.
Here is a quick overview of the causes of lawn mowers blowing smoke and the best solution for lawn mower cutting out and smoking after startup.
OverView Of All The Reasons That Make A Lawn Mower Smoke!
| Color Of Smoke | Cause Of The Problem | Solutions |
| Black Smoke | Disturbance in carburetors and fuel systems | Check the oil level. Fill with the right oil level |
| Dirty or Damaged Air Filter | Clean or Replace the air filter | |
| Problem in Carburetor | Secure the carburetor and adjust a little | |
| White Smoke | Overfill Oil Reservoir | Run the mower for 5-10 minutes |
| Oil Spillage | Secure oil caps | |
| Malfunction of the Head Gasket | Change with a new gasket | |
| Blue Smoke | Faulty Crankcase Breather | Mow on a 15-degree incline |
| Oil Spillage | Clean the oil after filling | |
| Mower tipped over incorrectly | Mow on a 15-degree incline |
Conclusion
In this guide, we tried to cover all the causes that can answer your question of why is my lawn mower burning oil white smoke. From why mower starts smoking then won’t move to riding lawn mower smells burning, we’ve tried to cover everything. If the suggestions mentioned above don’t work for you, approach your nearest lawn mower repair service. Have a Good Mowing!
