Chainsaws have made cutting wood an easy job. Yet they can run into problems, like any other household machine. One of the common chainsaw hitches is smoking. The smoke may come from the engine, the chain, and bar, or the exhaust passage.” But why is my chainsaw smoking?” you might ask.
A smoking chainsaw is scary, especially if you are new to working with one. Also, if the smoking is not checked and corrected early, the heat might damage the chainsaw beyond repair.
This comprehensive guide to smoking-related problems with a chainsaw will get you started on how to troubleshoot your chainsaw.
Table of Contents
Why is my chainsaw smoking?
Before you can establish why your chainsaw is smoking, it is vital to identify which part is producing the smoke. Knowing the source of the smoke will narrow down the possible causes and viable solutions.
Your chainsaw will produce smoke from these four parts:
- Exhaust channel
- Chain or guide bar
Once you have identified which section of your chainsaw is smoking, it is easier to point out what is wrong. Furthermore, it becomes easy to troubleshoot the fault.
Why is my chainsaw smoking from the engine?
When your chainsaw is smoking from the saw engine, it indicates that your machine has more profound problems. If not troubleshot fast enough, engine smoke can damage your chainsaw.
But what is the cause of the smoke? You can narrow down the severity of the problem depending on when the smoking starts.
Chainsaw smokes on startup
A chainsaw smoking as soon as you start the engine is bad news. It is a way the machine lets you know it needs servicing or getting insufficient fuel from the fuel tank. When this happens, the engine sucks empty air and overheats.
Please adjust the carburetor to feed a larger amount of fuel to your engine to correct this hitch. Follow your brand’s manual for this procedure since different chainsaw makes require varying approaches. While at it, confirm the brand’s recommended temperature settings.
Chainsaw smokes after working for some time
Your chainsaw starts well, runs smoothly, then after some time, it starts smoking. If this is your situation, the engine is overheating. An overheating engine reduces the lifespan of your machine.
Leaving the engine to overheat for long can damage other parts or burn them. If this is the cause of your smoke problems, you could damage your chainsaw in no time. The following reasons could be the cause of an overheated engine:
- Your engine is getting insufficient airflow
- Your exhaust conduit is clogged
- The ratio of oil to gas is incorrect
- A dull chain
- Overstretching your chainsaws ability
Engine getting insufficient air flow
Good airflow is critical for the smooth running of any engine. A chainsaw engine has an air filter that cleanses air as it gets into the machine. Over time, the air filter may trap dust and other microscopic impurities, which will block the airway. This cuts the supply of air to the engine and causes overheating.
This problem may occur more frequently during the rainy season. As you work with your chainsaw in the rain, moist air and raindrops may find their way to the air filter. When the dust mixes with the moisture, the mixture forms a layer on the air filter blocking incoming air.
To fix the air filter problem, remove the air filter and clean it. Put the air filter in warm detergent water, scrub it lightly, then leave it to drench. When dry, insert it back as per the manufacturer’s instructions. You could also blow the filter with your mouth or a pressure washer.
If the problem doesn’t go away after cleaning the air filter, consider replacing the filter with a new one.
Clogged exhaust conduit
The exhaust pipe of your chainsaw acts as the pathway for the removal of fumes. These exhaust fumes result from fuel combustion in the engine. When the engine is running, it gets warm, and so do the fumes.
If the exhaust pathway is blocked, the fumes accumulate inside the engine and cause the temperature to rocket. Clogging of the exhaust is rare. When it happens, you will find debris stuck on the port.
Apart from seeing the debris causing the clogging, you will notice a change in the chainsaw’s sound as it cuts through wood. Correct this problem by dislodging the stuck materials to allow seamless passage of exhaust fumes. This helps balance your engine’s temperature.
The ratio of oil to gas is incorrect
If you are using a gas-powered chainsaw, then your chainsaw engine utilizes a mixture of oil and gas in particular proportions. Consult your chainsaw manual for the right proportions. If you prepare the mix with an incorrect ratio, the engine will have a faulty operation.
You may be wondering why the engine needs oil to run. It is because the engine has pistons that require lubrication. Too little oil in the mixture will not lubricate the piston as required. The pistons will cause friction against the engine parts and raise the temperatures.
Always follow the manufacturer’s manual to prepare a fresh oil-gas mixture for your chainsaw before starting your work. If you suspect this is the cause of chainsaw overheating, drain the bad mixture from the tank and replace it with the right amounts.
You could try and balance the bad mixture, but that is only possible if you can recall the proportions you used to make the mixture. If you don’t remember, avoid wasting more fuel and oil in a mixture unlikely to help you later.
Another reason why the oil-gas mixture may cause engine overheating is contamination by water, dirt, or wood dust. Open your fuel tank and ensure the oil is clean. Also, check the containers you use to store the two liquids and ensure they are not contaminated. Similarly, maintain a clean working environment when mixing the fuel and the oil.
A dull chain
Prolonged use or cutting into the dirt can dull your chain. The duller the chain, the more power is needed to cut wood. When your chainsaw uses more energy than usual due to insufficient sharpness, the engine will overheat.
How to tell your chain is dull
First, when your chain is dull, it takes longer to cut into the wood. If you need to apply more pressure than you usually do, it is an indicator your chain needs sharpening or replacement.
Another indicator that your chain has lost its sharpness is the size of the wood scraps. A blunt chain will produce a powdery or dusty wood scrap. A well-sharpened chain, on the other hand, produces big wood fragments.
Besides, a dull chain will have a rough feel and damaged chain teeth.
How to sharpen your chainsaw at home
- Use a manual file. If you don’t know how to use a file, consider asking an expert to sharpen the chain for you at a fee
- Sharpen with a grinder
Overstretching your chainsaw’s ability
There are different brands of chainsaws depending on their ability (the size of wood they can cut) and price. Using a chainsaw for the recommended tree/wood size helps maintain a good condition and efficiency.
Using a small chainsaw on a huge tree can overstretch its engine’s ability by drawing more power than usual. When an engine is overworked, it consumes more fuel and overheats fast. Also, the wood can trap the guide bar.
Trying to remove the stuck guide bar can damage the chain teeth. It can also bend the bar. The right way to remove a stuck chainsaw bar from a tree or wood is using a wedge.
How to fix a bent chainsaw bar
It is possible to straighten a bent chainsaw bar. However, if the bend is severe, it would be better to get a new guide bar.
Follow these steps to unbend your guide bar:
- Place your guide bar in an upright position
- Get your screwdriver and unscrew the bolts holding the guide bar onto the chainsaw
- Remove the chain from the guide bar
- Dislocate the bar from the main body of your chainsaw and put it on a flat surface to gauge the bend
Straighten the ben using a rubber mallet until the bends are straight
Fix the chain back onto the guide bar
- Refasten the chained bar back to the main body and secure the bolts
Why is my chainsaw smoking from the exhaust conduit?
When you notice dark smoke coming from your exhaust pathway, it is an indicator that your fuel is imbalanced. Always mix the oil and gas in the stipulated ratio. The ratio varies depending on the chainsaw brand, though most recent chainsaws use an oil/gas mixture in the 1:50 balance.
To get rid of the smoke, remove the faulty oil/gas mixture from the fuel tank. Prepare fresh fuel as outlined in the chainsaw manual. Add the new mix in the fuel tank and run the chainsaw to ascertain the problem is gone.
Another possible cause of smoke coming out of the exhaust passage is an unstable idle. When you mount the idle incorrectly, it increases the engine’s idle speed, which causes overheating.
To fix this problem, do the following:
- Revolve the idle screw in a clockwise direction, checking the idle speed
- When the idle speed declines, rotate the screw in the opposite direction to 90 degrees
- Intensify the chainsaw’s throttle gradually as you watch out for the proper acceleration of the engine
Why is my chainsaw motor smoking?
This problem arises if your chainsaw is electric. When the smoke emanates from the motor area, it is an indication that your motor is overworking. To fix this, turn off the chainsaw and give it some time to shed off the heat and relax. You could use this break to rejuvenate your body.
If the smoking problem persists, then there is an internal problem causing the motor to overheat. Ensure the chain is well lubricated as this could put pressure on the motor and cause overheating.
In addition, check the ability of your chainsaw to avoid overworking the motor. Cutting hard and wide wood could exert extra pressure on the motor. If this is the case, only cut sizable trees to avoid damaging your chainsaw.
Why is my chainsaw smoking on the chain?
A smoking chain indicates possible excessive friction that leads to heat production at the point of contact with the wood. It is easy to diagnose this problem because a chain will start smoking after cutting wood for some time.
When this happens, there are three explanations for that:
- Your chain is dull
- The chain’s lubrication is insufficient
- Chain tension is too tight
Your chain is dull
If your chain has become blunt, either due to inappropriate use or cutting wood for long, it cuts wood slowly with a lot of friction. The more the chain rubs against the wood, the warmer it becomes. This heat accumulates after a long tree cutting session and could produce smoke or even sparks.
We talked about knowing your chain is blunt earlier in the article, depending on the size of the wood scraps and the appearance of the chain teeth.
To fix this problem, sharpen your chainsaw with a file, a grinder or take it to the local repair shop for sharpening.
Your chain is receiving insufficient lubricant
So you have checked your chain, and it is sharp enough. But the chain is still smoking. What is the next probable cause? Well, the problem might lie in the lubrication of your chain.
The first thing you should check is the oil tank. Ensure there is enough lubricant in the oil reservoir, and if it needs replenishing, please do so. If the oil is sufficient, then the problem lies in the channels delivering the oil to the chain.
How to test if the lubricant is reaching the chain
To check if your chain receives the oil, place the edge of the guide bar against a colored surface or a paper. Run the chainsaw, hold down the chain, and check if any drops of oil come through the chain and drop on the paper or colored surface.
If you don’t notice a string of oil drops, your lubrication network is faulty or blocked by dirt. The oil may be getting to the bar, but the distribution channels where the chain rotates on the bar. To fix this problem, loosen the chain from the guide bar to expose the oil distributing channel. Clean the small holes with a pressure hose pipe or a sharp object small enough to fit into the tiny holes.
If the chain continues to smoke after unclogging the oil distribution holes, the oil is not getting to the chain bar. This could be due to a faulty oiler passage.
Fixing this needs thorough troubleshooting and following the chainsaw repair manual. If you are up to the task, disassemble the guide bar from the chainsaw base. Locate the oiler passage. Run your engine and observe if the oil is dripping through the port.
If no oil flows through the passage, check for wood scraps and other impurities that might clog the path. Clear the pathway, then re-attach the bar and check if the problem goes away. If the problem is still there, consider taking the chainsaw to a servicing and repair shop near you.
Your chain tension is too tight
When you fasten the chain too tightly around the guide bar, the chain may fail to rotate around the bar. A tight chain could also increase the friction between the chain and the bar, overheating the chain.
Whenever your chain heats up more than average, it increases the chances of a fire outbreak. It also reduces the efficiency and life span of your chainsaw.
How to check if your chain is too tight
Before you check the tension, make sure to turn off the chainsaw and leave it to cool down. This prevents injuries to your fingers and possible burns from the hot chain and guide bar.
Here are the two ways in which you can check if your chain tension is correct:
Do a snap test
Hold the chain with your fingers and pull the chain downwards such that two drive links fall out of their rails on the bar. Release the chain and observe the chain’s behavior. When the drive links snap back onto the rails, the tension is proper.
However, if the chain resists your pull and stays fixed on the bar rails, the chain is too tight.
Pull the chain
This pull test involves pulling the chain away from the guide bar as far as your fingers can reach. If the chain extends too much, it is loose, while not getting any lift or movement of the drive links indicates a too-tight tension.
How to adjust a tight chain
Locate where your chainsaw’s tension screw is by consulting your manual. Most of the chainsaws will have the screw on the side panel or the front panel. Others come with an in-built tension controller with an external control handle.
After identifying your screw’s location, rotate the screw gradually with one hand while holding down the guide bar with the other hand. Revolve the screw, checking to make sure the drive links correspond well with the spaces in the guide bar.
A well-tightened chain will not show the drive links because the guide bar conceals them. Re-check the chain to ensure you have set the tightness at the correct tension. Re-adjust until you get the most suitable tension.
Other possible causes of a smoking chainsaw
Apart from mechanical problems. There may be other poor handling that may lead to your chainsaw smoking:
Cutting wet wood
If you are using your chainsaw during a rainy season, the heat coming from the engine can cause the moisture to evaporate. As the water evaporates, you may mistake the steam for smoke.
You could also experience the steam during drier weather when you cut a green wood such as a living tree. However, this is an indicator that your chain is hotter than usual. The problem’s source is an overheating guide bar-chain area rather than the wood itself.
Faulty carburetor needle
If the carburetor needle mounting is faulty such as leaving a gap, the oil will leak. The carburetor needle could also have perforations leaking the oil. When oil falls on a hot guide bar or chain, it will produce white smoke.
Check if this is the problem and tighten the needle. If the needle is damaged, replace it with a new one.
As you work on some wood, your chainsaw produces some noise. Gas-powered chainsaws are noisier than the electric kind. A silencer is the part of the chainsaw that cancels the noise or reduces it to safe levels.
Sometimes dirt and wood scraps stick on the silencer and block the pathway. The silencer may also hoard carbon from the engine fumes. A clogged silencer increases the temperature around the engine leading to overheating. Excess heat causes smoking.
To correct this problem, clean the silencer with warm soapy water and leave it to air dry. After drying, please put it back and check that the silencer is working as it should. Consider replacing the silencer after a year.
Tips and tricks to prevent your chainsaw from smoking
- Buy high-quality lubricant. Some cheap quality lubricants dry too fast and cause friction which in turn leads to overheating
- Clean your air filter regularly
- Always follow the manufacturer’s instructions when mixing your oil and fuel
- Pay attention when filling your oil and fuel tanks. Make sure you put the oil in the oil tank and the gas-oil mixture in the fuel tank
- When using an electric chainsaw, note the difference between lubricating oil and motor oil. Confusing these two could cause damage to your chain or motor
- Always run your chainsaw engine at the recommended speed. Use the manual to set the speed
- Maintain a well-sharpened chain at all times. Prepare your chainsaw for the work by oiling and sharpening the chain
A smoking chainsaw is a source of worry for any user. Evaluating the source of the smoke is vital to narrow down the possible cause and how to alleviate the problem. The main reasons for a smoking chainsaw are an overheating engine, too hot guide bar, and using badly-mixed fuel.
You can troubleshoot most of these problems with the help of the manufacturer’s manual. If the problem persists after doing the troubleshooting, consider taking the chainsaw to an expert repair guy.