This is Why Your Ariens Lawn Mower is Smoking

A lawn mower can create a cloud or smoke so large your neighbors may think you have a serious fire. A smoking mower can be very alarming. You may even start to worry you’re going to encounter a large repair bill or possibly have to replace your lawn mower.

An Ariens lawn mower will begin smoking when the air filter is plugged; the crankcase oil level is too high or too low; an engine gasket has failed, or a valve or piston ring problem developed in the engine. Oil spilled on an engine or muffler, or excessive fuel being burned in the cylinder can also create smoke in an Ariens mower.

Before working on your lawn mower, follow the safety guidelines listed in your owner’s manual to avoid injuries.

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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.

Reasons Your Ariens Lawn Mower is Smoking

Clogged Air Filter

Dirt and grass clippings tossed into the air while you mow create an atmosphere that can plug an air filter if it isn’t cleaned regularly. A plugged air filter restricts the amount of air your engine receives to create combustion and run.

First of all, never run your mower without an air filter. Not even if it’s for a short while you wait for a new replacement air filter. Without a filter, dirt, and debris can get to the engine through the air intake causing damage to the cylinder and engine seals.

Second, always run your mower with a clean air filter. I find it’s best to start each mowing season with a new air filter and clean it several times throughout the season. A plugged air filter will prevent air from passing through the filter and to the engine.

This air filter must be kept clean. I recommend replacing your air filter annually. Then check and clean your filter several times throughout the mowing season. Clean the mower frequently when you are mowing in dusty conditions.

Why does a plugged air filter cause it to smoke?

• The engine’s inability to get good air will cause your engine to run rich so black smoke will emit from your mower. This means the fuel and air mixture the engine requires to run has a higher concentration of fuel.
  
• Smoke can be a result of your air filter becoming so plugged, it restricts all air to the engine. The engine will begin drawing air from wherever it can find it including the engine crankcase. When it draws air from the crankcase, it can also pull oil from the crankcase that burns off in the cylinder.
  
• When your Ariens mower begins to smoke, the air filter can become plugged with smoke making your engine problem worse.

Follow these cleaning instructions for your type of air filter:

Clean an Ariens paper air filter element

• Remove the filter from the air filter housing.
• Wipe out any dirt remaining in the housing with a dry clean cloth. Do not allow dirt and other particles to fall into the air intake.
• Tap your filter against a solid surface to get as much dirt to become loose and fall out of the filter as possible.
• Hold your filter up to a light source. Reuse your filter if you can still see light shine through the paper. If you can’t, it’s time to buy a new filter and install it.
• Reinstall the air filter and attach the air filter cover.

Insufficient Engine Oil Level

Your Ariens mower’s engine manufacturer requires a certain amount of engine oil in the crankcase. This is not a recommendation. It is a requirement.

Having too much engine oil or too little engine oil in your mower can result in a costly repair bill or even an engine replacement.

Engine Oil Level is Too Low

A low engine oil level won’t give your internal engine parts the lubrication they require to move freely. When there isn’t enough oil, friction begins to build which causes your engine to get hot. It can become so hot that the oil begins to burn and engine parts begin to melt creating smoke.

Once you find your engine is smoking because of low engine oil, you can attempt to add fresh oil and run your mower.

Chances are, if your mower became so hot it began smoking because of low oil, you have caused engine damage that can’t be easily solved by correcting the engine oil level. You are better off bringing your mower to an experienced small engine mechanic to be diagnosed.

Because of the damage that can be caused by running a low level of oil, it is important to take a few minutes before each mowing to check your mower over including checking the engine oil level. It’s best to catch this problem early and avoid running your mower in this condition.

Engine Oil Level is Too High

You are aware that you shouldn’t run your engine when it is low on oil, but did you know running it with too much oil will also cause problems? Too much oil increases the pressure in the crankcase. This can push oil into the cylinder and even into the air intake through the valve train.

The oil in the cylinder will begin to burn off and create smoke. You can read more about additional problems you may experience when running too much oil in your mower in this article.

When you find too much oil in your crankcase, correct the engine oil level by removing a little oil. You can do this by removing a little oil through the drain plug or oil filter. You can also use an oil evacuator or turkey baster to suck a little oil out of the oil fill area.

Recheck your engine oil level using the dipstick once you have removed some oil. Continue to add or remove oil until the level is corrected.

Check your air filter to make sure it is not covered in oil or has become plugged from smoke. If it is, install a new air filter.

Bad Engine Gasket

Smoke coming from your Ariens could be the result of a bad gasket on your mower causing engine oil to leak. When oil is leaked onto a hot surface, like your muffler, it will begin to burn off and smoke.

Internal Engine Damage

The smoke coming from your Ariens mower may be the result of internal engine problems.

Once you have reached this section, it becomes increasingly difficult to identify the exact cause of your internal problem without tearing down your engine and performing leak-down and compression checks.

You can perform one simple check that will signify you have an internal engine problem, but it won’t tell you the exact problem. You’ll need a small engine mechanic to diagnose your engine to find the root cause.

While this check can’t tell you what kind of problem you have, you’ll know you have a problem that needs to be addressed by a mechanic.

To complete this check, remove your spark plug(s) and check for signs of oil on the plug. Oil on the spark plug will indicate you may have a piston ring or valve train problem.

Piston Ring Problem

Your engine will need to be torn down to find a problem with your piston ring. When a piston ring or scoring inside the cylinder wall is found, oil can enter the combustion chamber and burn off causing your

Ariens to start smoking.

Valve Train Problem

An Ariens mower that has overheated can develop a burnt valve. The only way to determine a burn valve problem is by removing the cylinder head and performing a leak-down test.

This test and repair should be performed by a small engine mechanic. The mechanic will have to cut the seat and the valve correctly to properly complete the combustion chamber.

Your Ariens Lawn Mower is Blowing Blue, White, or Black Smoke: What’s the Difference?

I always recommend going through the steps above to identify the cause of the smoke coming from your mower. However, identifying the color of the smoke can point you in the direction of the potential cause of the smoke.

Blue or White Smoke

This type of smoke is associated with the burning of excess oil. This could be from oil burning off in the combustion chamber from damaged piston rings, the valve train, or an engine gasket leak. It can also be the cause of oil being pushed into the cylinder from a plugged air filter.

Black Smoke

Black smoke is associated with excess fuel burning. This is due to a plugged air filter allowing the ratio of fuel to air to have a higher fuel concentration. When the Ariens mower runs rich, it can emit black smoke. If the air filter is not the cause, look for another air restriction in your mower.