Lawn Mower Is Burning Oil – Causes and Fixing Tips

If you suddenly get surrounded by white smoke while mowing your lawn, consider this to be the big reveal of your lawn mower burning too much oil. A faulty lawn mower with such a problem may produce blue/white or black smoke or consume more gas than usual.
Burning oil is a common problem in a lawn mower that is resolvable at home. Using the right amount of suggested oil blend and changing the old oil frequently, cleaning the air filter, and checking for any inconvenience in the carburetor, crankcase, and head gasket are the best ways to fix this problem.

Lawn mowers generally spout white smoke to discharge excess fuel. But the problem arises when the mower starts to cough up smoke abruptly, and it could also happen after a long period of inactivity during winter. Such situations are staggering, especially in a lawn mower for senior citizens. This article will help you understand the causes and help you look for a solution if your lawn mower is burning oil.

Causes of a Lawnmower Burning Oil

There are plenty of reasons for a lawn mower to burn oil and produce smoke. White smoke indicates a rise in fuel level, while black smoke refers to any inconvenience among the engine components.

Both old and new mowers may fall victim to high oil consumption due to poor maintenance.

Amount of Gas in Use

If the mower is running on low gas, then the engine will start to heat up, and the parts will undergo more friction. It will hamper the air-fuel ratio, and the mower will start to produce black smoke.

In contrast, if the mower has more fuel than it needs, the crankcase will be flooded when the mower runs over a slope or tipped over for cleaning. A flooded crankcase makes the oil thin which results in burning too much oil.

Using Old Gas

Using the unchanged fuel for an extended period often results in various lawn mower problems. Gasoline gets thick over time which affects the lubricating parts of the engine. The increase in friction caused by this effect, in turn, creates more heat and burns through more oil.

Using Wrong Gas

Not all lawn mowers use the same viscosity of oil grades, and using the wrong oil grade causes increase in oil consumption and white smoke. The manufacturer’s manual always mentions the oil grade required for a mower.

Some mowers use multi-viscosity oil, such as SAE 10W 30. It is worth mentioning that multi-viscosity oils are lightweight and burn faster than usual.

Flooding and Leaking

Oil leak doesn’t only refer to oil dripping over the body but also internal leakages too. A flooded ignition chamber or crankcase and oil leaks in the carburetor and the air filter are the causes of internal leakage. A carburetor float regulates the supply of oil to the engine. When it gets stuck, the solenoid fails to control the flow and floods the crankcase vacuum with excess oil.

How To Fix Lawn Mower Is Burning Oil

A lawn mower that burns too much oil is not that hard to fix, and you do not need to be an expert to solve this problem either. With some time to spare, some household tools, and the help of these few tips given below, you can fix your lawn mower in no time.

Replace the Old Oil

The best place to start is by checking the oil, as this is where all the troubles begin. Because old oil gets thicker, it always creates problems in different engine components. The oil in push mowers needs changing after every 25 hours of use and riding mowers after 50 hours. Remember to follow the manufacturer’s guide for the suggested oil grade while changing the oil.

Pour the right Amount of Oil

Filling the tank with the precise amount of gas is a vital job, but this step is often overlooked. Both excess and insufficient fuel level are harmful to any lawn mower. Go through the user manual to know how much oil your mower needs, as this information varies from model to model. Use the dipstick to measure the oil level while pouring.

Clean the Air Filter

The air filters in a lawn mower may get covered with dirt and sometimes even get wet. The air-fuel ratio becomes unstable if the air filter fails to perform correctly. Remove the shroud and then clean the air filter. If the filter is damaged or covered with oil, it is time to buy a new one.

Check the Crankcase

If there is an upsurge in the fuel level, then the crankcase may have been flooded. The crankcase is connected to the solenoid that controls the starter engine. If there is oil dripping from the crankshaft breather, then you need to check the crankcase area for excess oil. If there is any, dispose of the extra oil and clean the carburetor. Always remember to follow the manufacturer manual to locate each of these components.

Clean the Carburetor

As mentioned before, both expired gas and a low amount of gas affect the carburetor’s function. Insufficient air supply stresses out the piston inside the carb and the increased friction caused by dense oil makes the lawn mower overheat. Clean the carburetor if the crankcase is flooding and the lawn mower is overheating and discharging white smoke.

Check for a Blown Head Gasket

A head gasket seals off the engine block to ensure that the combustion engine is running efficiently. The lawn mower will suddenly stop working if there is a blown head gasket. Blown head gaskets produce black smoke, burn oil and overheat the engine. Also, check for oil leakage around the gasket or the engine block. It’s safer to replace the head gasket if this is the reason your mower is burning oil.

Safety Tips When Fixing Lawn Mower

Following the steps mentioned may be easy. But it would be best if you kept in mind a few things while doing so, such as:

• Always tilt the mower with the spark plug facing upwards to prevent the crankcase from flooding with oil.
• Read the manufacturer’s guide before fixing any problems as a wrong turn may lead to an even bigger problem.
• Remove the spark plug before performing any of these instructions.
• Remember the placement of every engine gears before disassembling. Take photos if necessary.
• Use gloves whiles cleaning the carburetor and the air filter. Follow the manual for effective cleanliness.

“Prevention is better than cure”- this also goes for a lawn mower. If you do not pour too much oil in the tank or start mowing with too little oil to begin with, and change the fuel every month, you may not need to deal with any overheating issues. Overheating damages any mechanism, and it will eventually slow down your mowers’ efficiency as well.

It is not impossible for a lawn mower to burn oil even if you took care of it accordingly. Sometimes overheating and burning oil refers to or may lead to more serious problems that these tips mentioned above may not do the trick. Seek professional help in such a situation.

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