When you have used your lawn mower for a period, it tends to develop some kind of fault or the other especially if it is not periodically maintained. One of the major concerns of lawn mower users is that the lawn mower is smoking. This is a common issue with lawnmower engine because there are working fluids like gas, engine oil and air needed for the lawn mower to work smoothly. In this post, you will see the reason why your lawn mower can or is smoking, and more importantly, how to fix it yourself without necessarily contacting a technician.
The basic reason why a lawn mower is smoking is because there’s too much oil in the engine. But apart from this, other factors like a worn out head gasket, a faulty crankcase in the engine block, or oil and gas mixed together in the tank when the mower is tipped over can also cause the lawn mower to start smoking.
And yes! we know you can’t help but tip your lawn mower over sometimes especially when you want to have it cleaned, but this can pose another type of threat to your engine as oil might end up mixing with gas. So you have to be careful with that one.
If your lawn mower is smoking, it might not pose an immediate threat to your lawn mower. But if left unattended to, it can lead to severe damage to your engine as well as pose health risk due to inhalation. It can also cause depletion of the ozone layer among other environmental hazards.
A smoking lawn mower is avoidable, but it happens. So let us now take an extensive look at the reasons why a lawn mower can be smoking. Check here for detailed lawn mower maintenance.
REASONS WHY LAWNMOWER IS SMOKING
If you notice that your lawn mower is smoking, one of the reasons below is the cause.
Excessive oil in the engine
The engine oil consumption in a lawn mower is not as much as that of a vehicle or other bigger engines. With just half and a quarter (3/4) of oil, your lawn mower is good to go. However, most people just make the mistake of pouring excessive oil into the engine, without gauging the engine with a dip stick.
This causes more harm than good to the engine of the lawnmower. They almost naturally assume that the more the oil, the better so they fill to the brim which is wrong. So when you start seeing smoke from your lawn mower, that’s your engine trying to burn up all the excess oil.
You might need the engine to run for a while longer before it stabilizes, or you drain the excess oil from the engine. In the long run, not only will excess oil cause a smoking engine, it can also lead to damaging the engine.
Oil in gas
A mixture of oil and fuel in the fuel tank of the lawn mower will cause smoking. This can happen when you accidentally pour engine oil into the fuel tank.
This might also occur when you leave the lawnmower for someone who does not have so much experience handling it.
This will definitely cause the engine to smoke. Just like the first, the remedy to this situation is that you will have to completely drain the fuel tank, wash it with fuel and then replenish it.
Gas in oil
Okay this case is common too. When the fuel mixes with the oil in the engine it could cause the engine to start to smoke. And when fuel starts to sip into oil chambers, it means the carburetor oil has failed. It is not even safe to turn on the engine at this point, as it can cause damage to it.
You will need to change the oil completely and then clean the carburetor thoroughly. We have already done a guide on how you can clean your carburetor so it becomes as good as new.
So one of the ways to detect this fault is that your engine oil will smell like there’s gas in it. Once this is detected, fix up immediately so it does not cause further damage to the engine of the lawn mower.
Top gasket issues
If the gasket head has issues, then chances are that your engine will smoke. The role of a gasket in an engine is to provide sealing for the combustion chamber.
Usually, a gasket is made of graphite and metal. It can be found between the cylinder head and cylinder block of the engine. One of the signs of gasket failure is a popping sound in the engine.
This is the sound of failed compression in the cylinder. So the remedy to this failed gasket situation is to replace it entirely. Top gasket failure is usually common in overhead valve engines. So when the gasket fails, oil sips into the cylinder and then the engine begins to smoke.
WHAT CAUSES LAWN MOWER WHITE SMOKE
By now, you must have noticed that more often than not, the color of smoke your lawn mower produces is white. And after a time of puffing, it fizzles out on its own.
After you start the engine and the white smoke does not stop on its own after it comes out, then chances are that your oil tank is too full. If this is not the case, then maybe you accidentally spilled oil on the housing of the lawn mower when you were trying to top it up.
This oil can sip into the crank case and cause the engine to smoke. Another factor that can cause excess oil in the engine is when you use your lawn mower at a 15-degree inclination, or you purchase a new lawn mower and it already came with its own oil residue.
The first solution to this problem is that you will need to allow your lawn mower engine run on idle for a couple of minutes to just let the white smoke fizzle out. But if after about 15 minutes this white smoke continues, then we have to go technical. You will need to check the oil seal and make sure it is not damaged or worn out.
A worn out oil seal will let oil sip into the engine. We do not want this at all! A complete over haul will be needed as the cylinder and piston rings would have to be checked. Another part to look at is the top gasket. Make sure it is not damaged. If it is, you will need to change it out rightly. No repairs!
WHAT CAUSES LAWN MOWER BLUE SMOKE
Seeing blue smoke coming out of your lawnmower is rare, but it still happens. The factors that causes blue smoke are consistent with the ones that cause white smoke.
They have already been discussed above, but we will quickly do a recap. Stuff like oil spillage on the lawn mower parts that fizzles into the engine and an over filled crankcase are the prime suspects. Add that to an over filled oil tank and we are making progress.
But one thing that stands out about blue smoke is that you probably used the wrong oil grade for the lawn mower and now the engine is reacting to it. All engine oils do not have the same chemical properties. So do well to use only the one recommended by the manufacturer.
WHAT CAUSES LAWN MOWER BLACK SMOKE
Of all the colors of smoke to see coming out of your lawn mower, black is the worst. Once your lawn mower engine starts producing this color, it means that the fuel line, air filter and the carburetor are beginning to have issues.
The carburetor is in charge of supplying the correct air/fuel mixture into the combustion chamber of the engine. Once air is short, fuel becomes too much, or if fuel is short, air become too much.
This causes a huge imbalance in the air/fuel ratio which will in turn cause the engine to produce black smoke. To begin the solution journey for this problem is to first check the air filter. Chances are that dirt and debris have clogged it up and is hindering the flow of air into the carburetor. Check here for top carburetor cleaners.
Bring it out from the unit and clean it with soapy water. If the air filter is bad, then replace it entirely. Once this is done, start the lawn mower and allow the engine to run on idle for a while.
See if it has stopped smoking. If it hasn’t, then we will need to check the carburetor, because in over hauling the carburetor, you will also see if the fuel line has been clogged up and work on it.
Conclusion
A smoky lawn mower is very hazardous to life, property and environment. Once it is detected, try all means to correct it the first time before it leads to something else. If you want to avoid all of these smoke issues, then we recommend you opt for the battery powered, electric or robotic lawn mowers.
