Lawn mower blowing blue smoke is an issue that can happen due to several reasons, like tilting the mower beyond fifteen degrees, filling the oil beyond the marked level, oil being in the wrong compartment of the mower, and the mower being overused without proper maintenance.

Guide to FIx Mower Blowing Blue Smoke

If you need to know which of these reasons applies to your riding mower, our gardening team is here to help you with the proper task.

Read on as we inspect each of these reasons individually and their fixes to help you solve the causes once and for all.

Why Is The Lawn Mower Blowing Blue Smoke?

The lawn mower blowing blue smoke is due to tilting your machine incorrectly and when you have overfilled the engine oil. On another note, it would also happen when there is oil in the fuel compartment and if the engine has gotten bad. 

If your mower emits blue smoke, it usually means burning off the excess oil. It is also essential to know the exact cause causing the oil burning. The smoke mostly lasts for ten to fifteen minutes; if it exceeds this limit, seek professional help immediately. 

– Tilting Your Lawn Mower Incorrectly

When the oil has escaped its compartment, it creates a huge mess, and at least a major chunk of the oil will burn off, leading to the emission of smoke, mostly blue. Remember that many other incidents can occur if your mower tilts beyond 15 degrees. 

It is one of the most common ways that allows the oil to reach places it is not meant to be. The mower is tilted to examine the lower side of the deck or when there is a need to replace the blades. When you want to cut the grass of your lawn on a steep slope can also cause the oil to spill. Most mowers are designed in a way that they need to be tipped to one side only and not the other.

Burning oil is when the engine would cause blowing blue smoke is hard to miss, but if you think you will not be able to notice the light-colored smoke, keep an eye on the air filter in this case because you don’t want to harm it. First, it will show some blue to gray-colored smoke from the mower, but be sure that you don’t inhale the mower smoke.

You will also see that the smoke is coming out when the oil leakage is because of tilting the mower, and as it doesn’t stay adequately on the ground, you would use it. In addition, if the oil leaks because of this specific reason, there is a chance that the air filter is soaking in oil.

– Overfilling Engine Oil

Fuel is food for the engine, and this is such a common reason why most people would aim to fill it more than the necessary amount. Hence, the engine does need its fuel, but it is within a specific amount. Even though a lawnmower needs half the amount of engine oil as a car, it is equally important, but the engine will suffer if the oil is either less or in excess because the amount would leave such an impact on functionality. 

Since you need to change the oil often, there are increased chances of the oil pouring in than the required amount. We usually add or change oil to the mower when it shows that it is low on oil, but we do not know that it is one of the factors that lead to blue smoke emission. You can always check if this is the reason for the smoke by quickly checking the dipstick.

Reasons of Mower Blowing Blue Smoke

The lawn mowers are just as capable of blowing white and blue smoke as overused or slightly used ones. It happens so because oil has leaked into the engine. It is common for oil to spill when you add or change the oil, when you overfill the crankcase with oil, or when you add oil to the mower when it is tilted, leading to smoke emission when it reaches parts like the spark plug.

– Oil in the Fuel Compartment

This issue is subjective to your mower’s engine, and in a two-stroke engine, there is only one compartment where the oil and fuel go together. But if your mower has a four-stroke engine, there are two separate compartments: oil and fuel. You must also know that different mowers that you invest in would have a different way of needing fuel.

For instance, the Briggs & Stratton sae 5w-30 synthetic small engine motor oil needs it sufficiently, but not more than its required amount. You would see that when there is an excess amount of oil in the crankcase, the machine would be in a risk to show blue-colored smoke. 

Still, smoke, blue or white, can emit from both kinds. A two-stroke engine produces blue-hued smoke if you mix too much oil in the fuel, and as the engine runs, the oil burns off with the gas; such a mower would be the Briggs & Stratton lawn mower oil 18 oz 100005 case.

In these cases, you must carefully look out for bluish smoke if you add fuel to a four-stroke engine with oil and gas. This affects the lawnmower’s performance, and the engine might get damaged because this smoke indicates something has gone wrong. 

This can be the same case for a new mower. The engine of a new mower also smokes when turned on for the first time. But it is not something to fuss over. 

On the other hand, at times, there is residual oil in lawn mowing machines, leading to smoke emissions with blue color. Some common oils used for mowers include the Countyline lawn mower oil, the super tech conventional sae 10w-30 lawn mower oil, and even Powercare premium-grade 20 oz. 10w-30 lawn mower oil.

– The Engine Parts Have Gone Bad

Over-worked or mishandled lawn mowing machines are equally the causes of the emission of smoke as the rest of the above three reasons. The damaged head gaskets, or a blown head gasket, piston rings, spark plugs, and cylinders are the most common engine parts that cause the small engine to blow white or blue smoke. 

If you have gone through the rest of the possible causes, and you think none of them is the cause, one of the engine’s parts likely holds the sole responsibility. Furthermore, the engine parts go wrong in the cold season too.

This would also be possible if you start seeing the white smoke and the leaked oil reaches places that ought to be far from its reach, and this is would show you that there is a compartment or a filter that has been weakened in the long run. You may ask, is white smoke from lawn mower dangerous, and yes, the mower blowing white or any other smoke harms your health and your mower’s health. Do not inhale the smoke from burning oil; a quick lawn mower white smoke fix. 

How To Fix it?

To stop the lawnmowers from blowing blue smoke, first clean the oil and the air filter, and drain the excess oil out. After that, get the oil out of the fuel, but if you are still seeing this, then you should take some help from a professional.

Most of the solutions are quick fixes, and you only need help from a professional if things progress. The solutions are all based on ways to help you ensure that the excess oil escapes the lawnmower.

– Clean the Oil and Air Filter 

In such a case, the best you can do is wipe away any excess oil and then allow the remaining oil in the combustion chamber or the other inner parts of the engine to dissipate as the motor runs. Once this oil has burned off, you should not see any blue-hued smoke, and this way, with the new set, you will see it properly running. 

Moreover, if you are sure this is very cause of the smoke, check for a dirty air filter. If it has lots of oil on it, consider replacing the air filter, and this would help in the process because there would be no dirt or debris stuck, and this way, the smoke should stop. While you are at it, check your carburetor, as the oil could have sneakily leaked there, and that can be why the lawn mower blows white smoke and then dies.

– Drain the Excess Oil Out

Dipsticks tell that the crankcase is filled with oil, and it is time you drain the excess oil out. This task can be simple or complex depending on the make of your mower. Either way, the best way to go about the situation is to completely drain the oil and then refill the oil filter according to the suggested amount, and then let it out as much as you can, make sure you would invert it and keep it still.

Mower Blowing Blue Smoke Solutions

After you have added the oil, double-check if it is according to the specifications. Although several gardeners would assume that a bit of extra oil is harmless, that is not necessarily the case, because you must not fill it to leakage.

While under-filling is a bit of work, excess oil leads to more smoking and more work for the engine because you don’t want to go through that trouble again. Now, you should make sure that you avoid tilting the mower and instead try to run it in without any tilts or moving it from the grounds, and you will be free from damages like oil spills and risking any smoke being mixed with gas. 

– Get the Oil Out of the Fuel

If you have a two-stroke mower, and there is too much oil in the fuel, but not much fuel left behind, you can use the mower until the remaining fuel burns out. Two-stroke engines are primarily made to burn an oil or gas mix, and as a result, this makes the odds of you getting into any trouble reasonably low. But you must remember that if you have a four-stroke engine and oil is in your fuel, you must be very careful. 

You have no option but to drain all the contaminated oil out of the fuel and add fresh oil or gas. The same applies to a two-stroke mower. After doing everything you can to drain the contaminated oil, check the oil level once again, and replace any leaked oil. A little smoke still comes out as the residual oil burns off, so ensure that you avoid this hazardous issue.

If you have turned on your mower for the first time, allow it to run for over 10 minutes so that it will adjust to the circumstances, and you won’t see this smoke as the machine is clear now. But, if still, smoke does not stop, then it might be more of a serious problem, which means you can now return and replace your new mower is the best choice in this case.

– Take Help From a Professional

You need a description or a manual to fix the engine’s internal parts. If you have a limited amount of engine knowledge, and you are that it is not the other causes that cause the smoke, we recommend getting a diagnosis done by a mechanic and then working your way towards the repair. 

A professional can pinpoint the exact cause that led to all this mess and then guide you on your next step and suggest keeping your mower well-maintained so that you do not have to deal with such issues in the future.

Mower Blowing Blue Smoke


Understanding why your lawn mowing machine is blowing blue smoke is simple now that you have given our article a thorough read, and you have even learned how to avoid and solve the underlying causes.

Before you leave, let’s quickly summarize the key points we discussed so that you are fully prepared to help your mower:

  • Always read your mower’s manual before tipping it to any side. You will do your future self a huge favor.
  • Refrain from filling the oil reservoir. Dipping a dipstick is an easy and fool-proof way of telling if you have overfilled the oil.
  • It is crucial to know about the type of mower you have. The number of compartments varies in the two-stroke and four-stroke engines, so be careful where you put the oil.
  • We often overuse our mowers without realizing that the engine parts must also be looked after. Overworked engines lead to the lawn mower blowing smoke.
  • If things look out of your control, there is always time to take advice from a professional by taking your mower to your nearest repair shop.

After going through our recommendations, you can save your mower in so many ways, especially by taking precautions so that it does not blow out smoke.

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