Why your Chainsaw Smokes and What to Do About It

Oftentimes when using a chainsaw, it heats up. From a scientific point of view, it is simply an act of energy conversion. The electrical or chemical energy that powers your chainsaw, is converted to mechanical energy.

Why your chainsaw smokes? The most common cause of smoking in a chainsaw is when there are too many sparks coming out from the cutting area or blade. This means that you need to sharpen your chain because it has become dull and needs more power than what you are supplying it with.

Another cause for smoking in a chainsaw would be if there was not enough oil present on the bar lubricant which makes the saw stop working altogether and smoke due to friction.

Friction is a type of force that resists motion between surfaces. It causes a heat buildup when you cut items, so some of the mechanical energy is converted into heat energy while the rest is used for cutting the object. Sorry about the science lesson there guys.

However, while it is normal for your chainsaw to heat up to a reasonable extent, it is not meant to smoke. Smoke fumes from your chainsaw could be a result of a variety of factors.

In this article, I will list the causes, teach you how to diagnose the fault, suggest some remedies, and discuss some safety guidelines to note when using your chainsaw to prevent it from smoking so your tasks do not get delayed and so you can prolong its longevity.

Causes of Smoking in Chainsaws

It is very important to know the causes of smoking in chainsaws, as this can be a sign that something is wrong with your chainsaw and could lead to an emergency situation.

 

Why your Chainsaw Smokes and What to Do About It

 

Obviously, smoking in chainsaws is a bad sign, and here are a few factors that lead to it.

1. Using an Improperly Lubricated Chainsaw

When the chain of a chainsaw is not properly lubricated, friction increases and the amount of work to be done by the chainsaw also increases.

This in turn leads to it overheating and eventually smoking. Chainsaws usually come with automatic oilers or pumps, designed to effectively lubricate their chains. When this mechanism does not work, the chainsaw moves with difficulty through the bar.

To troubleshoot and confirm whether the dull chainsaw is the root cause of smoking in your chainsaw simply follow this action plan.

If the chain is properly lubricated there will be oil stains on the wood surface. If not, you would not find any. If none is found, here is a corrective measure to help.

  • Increase oil flow from the pump by turning up the oil pump dial and repeat the troubleshooting test above.
  • If this proves not to help, change the chain. 
  • Once again, if this does not help, check the pump mechanism as it may be clogged with impurities.

2. Using a Chainsaw with Dull Teeth

With consistent use of a chainsaw over time its teeth dullens. This means your chainsaw will be unable to make clean cuts and you would have to put in more effort to fell trees.

You not only feel the strain of the dull teeth but the chainsaw feels it also. As a result, your chainsaw could begin to overheat and yield smoke emissions. Therefore, as preventive maintenance, it is advised to sharpen your chainsaw’s teeth by a professional or by yourself. Sharpening its teeth could be done manually or electrically.

Sharpening manually does have a lot of cons such as uneven filing of teeth and taking a much longer time to do. Electrical sharpening is done by grinders which have none of the disadvantages of manual sharpening but for the fact that they could be 20x more expensive to purchase.

Therefore, to sharpen your chainsaw’s teeth manually, you would need 3 items. A filing kit, a file gauge as well as a stump vise.

 

 

To manually sharpen a chainsaw:

  • Ensure that the stump vise provides a steady grip on your chain. 
  • Your gauge must be in contact with your chain and its arrows should point in the direction of rotation of the chain. 
  • The filing gauge must be set to the correct angle so the cutter will be filed appropriately. The angles could be the top plate filing, file down, or side plate cutting angle and the depth gauge setting. 
  • Finally, using the round file, file the chain’s teeth as evenly and smoothly as possible.

To sharpen using an electric grinder, follow the instructions provided in your instruction manual. They could vary depending on the manufacturer. However, the core concept of use is to 

  • Lock the chain into place at the base of the grinder using the sliding guides and the chainsaw.
  • Set the angle at which you would prefer the chain to be sharpened. 
  • Finally, lower the grinding wheel so it skims the chain tooth. 

3. Use of Alternative Fuels

When purchasing a chainsaw, its user manual clearly states the recommended fuels to be used with it. By fuels, I am referring to both gas (if you are using a gas powered chainsaw) and oil (for lubricating the chainsaw).

Failure to use these oils in the correct ratio could result in overheating, performance problems, improper clutch engagement, power loss, and fuel vapor lock to name a few. It could also result in the deterioration of parts of the engine such as the carburetor, fuel line, and gasket.

To ascertain whether your chainsaw smokes due to the wrong oil and fuel mix ratio, you would first notice that the smoke emissions are darker, that is, you have got black smoke emissions. Then, drain the chainsaw’s tank and refill it with the right oil-fuel mix as indicated in your instruction manual. At this point, your chainsaw should be working fine.

4. Using the Wrong Filters

Another cause could be a clogged and dirty filter. Regulated airflow is necessary for chainsaws to work in top condition. The pattern of airflow within a chainsaw involves an intake of surrounding air, then the air is mixed with the oil-fuel mix. This combination of air, oil, and fuel is then burned to keep the chainsaw in operation.

Finally, it is exhaled. Now, the filters can get clogged because while the chainsaw is in operation cutting wood, a lot of the debris gets absorbed into it. Therefore the residue of the air, oil, and fuel mix will remain trapped in the chainsaw causing it to smoke. It is advised that air filters should be changed after every eight hours of use of the chainsaw.

To change or clean the air filter, simply wash it using a light brush and warm soapy water.

5. Incorrect Idle Setting

If you notice the chainsaw smoking on startup, it could be as a result of idling the chainsaw at a very high rate. It implies that the engine is running on mostly air, that is, its air intake is far greater than its fuel intake. This leads to the engine of your chainsaw overheating. To fix this issue, simply lower the idle setting of your chainsaw as instructed in your chainsaw’s user manual.

6. Damaged Electric Chainsaw Motor

The problem could be the motor of the chainsaw. Motors wear over time and if they happen to be run on a higher capacity than they could handle overheating occurs. If the motor is not diagnosed quickly enough, it could get damaged beyond repair.

7. Over – tightened Chain

Finally, if the tension of the chain is too high, it results in metal on metal friction between the chain and the guide bar of the chainsaw. This will cause smoke and become a fire hazard if it is not remedied immediately. A loose chain is a disaster waiting to happen as it could detach from the chainsaw while in use.

To lessen the tension of your chain to the right setting:

  • Locate the tension screw and use a wrench to tighten it.
  • Use the pull or snap test to determine if the tension is just right.

The tension of a chainsaw chain is one of the most important factors in determining the efficiency and lifespan of the saw.

How to Maintain your Chainsaw

  1. Always inspect your chainsaw.
  2. Ensure that you are using the oil recommended for your chainsaw. 
  3. Never run your chainsaw on an empty oil tank.
  4. Ensure that the chain is not tense as it will restrict motion.
  5. Always change the air filters after use.
  6. Sharpen the teeth of your chainsaw regularly.

A smoking chainsaw is not ideal and care should be taken when it is noticed. As discussed, it could be caused by any of the following factors; the wrong oil-fuel mix, a tense chain, an impure filter, a clogged exhaust port, etc.

Smoking is a problem that plagues many chainsaws, and it may require you to purchase a new one. Smoking chainsaws are an indication of the engine being starved for oil or gas. The best way to fix this issue is by adding more fuel and lubricant if necessary.

Smoking in chainsaws is a common problem, but it’s not always easy to know why this happens. Your chainsaw must be properly maintained at all times to boost its lifespan, reduce downtime costs, and save you from accidents.