chainsaw smoking? 🤔
Don’t PANIC! – This is the first rule.
It’s a problem that chainsawers often face. I’ve also been to that place (can’t lie!).
If your chainsaw is smoking, it could be because the oiling system isn’t working right, the air filter is blocked, the engine is going too fast, or the fuel-oil mix isn’t right. Plus, if you’re using a dull chain, it might make your chainsaw smoke when cutting.
But how do you fix a chainsaw that’s smoking?
Well, that’s what this article is all about!
I’m Sam and I have more than two decades of experience in chainsaw repair and maintenance 😎. In this article, I’m going to share with you the methods to fix your smoking chainsaw.
Are you ready?
Let’s get started…
Chainsaws have a 2-stroke engine which requires unrestricted airflow (more specifically, OXYGEN!) to burn fuel & generate power.
The air filter plays an important role in this process!
Its job is to trap dirt & debris, preventing them from entering the engine’s combustion chamber and clogging it up.
But as time goes on, the air filter gets all clogged up and doesn’t let enough air through. This means your saw doesn’t get enough oxygen, which leads to carbon building up and, in the end, makes your chainsaw smoke.
Here’s a pic of one of my “nasty” looking chainsaw air filters: 👇
How to Tell If Your Air Filter is Clogged Up?
Here are 4 sings that there’s something wrong with your chainsaw’s air filter:
- Check the air filter: Open the back cover where the air filter is located and inspect it. Check for dust, dirt, or debris!
- Black smoke: If your chainsaw is emitting BLACK smoke, it’s a sign that your saw’s air filter is all clogged up!
- Poor acceleration: When the air filter gets dirty, it limits the airflow. This results in poor acceleration & lower engine power.
- Poor fuel efficiency: A clogged air filter also reduces fuel efficiency.
How to Fix This?
If you’ve noticed any of these symptoms, just clean or change the air filter, and your chainsaw should be back to normal.
- Simply take the air filter off,
- Soak it in a mild detergent solution & brush off any dirt.
- Let it dry completely before re-installing.
If you use your chainsaw daily, it’s recommended to clean the air filter weekly.
However, if you want to SKIP the cleaning part, replacing it is your BEST bet! I usually replace my air filters once every 2-3 months.
You Put Too Much Oil in the Gas
If you’re noticing a lot of smoke coming out when you start your chainsaw, chances are you’ve mixed too much oil with the gasoline.
Here’s what you need to know:
2-stroke engines require a mixture of gasoline & oil. The oil lubricates the cylinder, piston, and other internal parts. This ensures smooth performance and prevents overheating.
But if you put too much oil in the mixture, it can cause excessive smoke, generate carbon buildup, and reduce the total power of your saw.
Ideal Oil-Gas Ratio for a Chainsaw
Most 2-stroke chainsaw engines require a 50:1 fuel-to-oil ratio. This means for every gallon of gas, you should mix in 2.6 ounces of oil.
| MIX RATIO TO 1 | 1 GAL. | 2 GAL. | 2.5 GAL. | 4 GAL. |
|---|---|---|---|---|
| 50 | 2.6 oz. | 5.1 oz. | 6.4 oz. | 12.8 oz. |
However, depending on the brand & model of your saw, this ratio can change.
For example, Husqvarna recommends a 50:1 oil/fuel ratio for chainsaws up to and including 75cc, while a 33:1 ratio for chainsaws 76cc and above. (Source)
So always refer to your manufacturer’s guide for the specific ratio that applies to your chainsaw.
What If You've Accidentally Mixed Too Much Oil with Gas?
Don’t get MAD if you’ve put too much oil in the mixture.
Dump out the oil and gas from the tank, mix a new batch of oil with gasoline according to your manufacturer’s instructions.
Here’s a video tutorial that explains the same thing (but in a more detailed way): 👇
Your Chainsaw is Idling Way to Fast
If your chainsaw smokes only when it’s idling (not when you’re using it to cut wood), it might be because your saw engine is idling way faster than it should!
Let’s dig a little deeper 🕳️
The carburetor in a chainsaw is responsible for controlling the fuel & air mixture that is sent to the engine.
When there’s too much fuel, the engine will run “rich“, idle faster, and produce more smoke and waste gas than usual. (Source: Hunker)
I know what you’re wondering: “How do I fix this?“
Luckily, it’s not that complicated! All you need to do is adjust the idle on your chainsaw carburetor.
Adjusting the Idle Speed on a Chainsaw?
1. Locate the idle-speed screw (usually labeled “LA/T“) on your chainsaw (check the image below for reference).
2. While the chainsaw is running, take a screwdriver & turn the idle speed screw in a clockwise direction (in small increments) until the chain starts to move.
3. Then, turn the screw back counter-clockwise until the chain stops moving.
4. Watch the smoke from your chainsaw – if it disappears, you’ve tuned the idle speed correctly.
However, if you’re experiencing poor acceleration after the new adjustment, tweak the idle screw a bit more until you get the desired result!
Recommended Idling Speed for Chainsaws
The recommended idle speed for chainsaws is between 2500 and 2700 RPM (Revolutions Per Minute). You can use a tachometer to check the RPM of your chainsaw and make sure it falls within that range.
Note: Depending on the model, some chainsaws may not run well at that RPM range – so don’t forget to consult your chainsaw’s manual for the correct RPM!
Your Chainsaw isn't Oiling
If your chainsaw is smoking from the bar & chain while cutting, it’s a sign that the oiling system in your chainsaw isn’t working.
This means that the bar & chain can’t get enough oil to stay “lubricated” while cutting, which causes extra heat and smoke.
And frankly speaking, there are TONS of reasons that might lead to the issue, but the common causes –
- Empty oil reservoir,
- Dirty or clogged-up oiler holes, and
- Faulty oil pump.
Okay! but now the question is – how do you fix it?
How to Fix a Chainsaw that's Not Oiling?
1. Check the oil reservoir: Make sure it has the right amount of oil with the recommended viscosity. If it’s not, what are you waiting for? Top it up!
2. Clean the oiler holes: Oiler holes are the small holes located on the end of your guide bar that help supply oil to the bar & chain. If these holes get all dirty and blocked, take a screwdriver to clean them out. That way, the oil can keep flowing like it’s supposed to.
3. Replace the oil pump: Try running your saw while the bar and the chain are off. See if the oil pump is working correctly (check if fresh oil coming out of the oil outlet port!). If not, then there’s something wrong with your oil pump.
How to Check if Your Chainsaw is Oiling?
Point the tip of your chainsaw at a light-colored surface, like a piece of cardboard, and start throttling. If you see oil droplets coming out of the tip, it means your chainsaw is oiling just fine.
💡 TIP: Check if your saw’s oiling every time you refuel.
Your are Using a Dull Chain
If any of the above didn’t solve the issue, it might be because your chainsaw chain is not sharp or it wasn’t sharpened the right way.
A dull chain won’t be able to cut through wood.
And if you push too hard, it will keep rubbing against the wood, making friction and heat, which can make smoke.
Signs that Your Chain is Dull
Here’re a few tell-tale signs that indicate that your chain is dull:
- Your chainsaw produces fine sawdust instead of wood chips.
- You can’t get a straight cut. (Here are 7 other reasons why your saw might be cutting crooked!)
- You feel a lot of vibration when cutting.
- Smokes come from the bar & chain.
If you’re facing any of these problems, it’s time to sharpen your chainsaw chain.
Here’s a Video Guide by Steve that shows how to sharpen a chain the right way:
However, if your chain is completely “grounded” (means it’s beyond sharpening), replace it!
Make sure the chain you choose is compatible with your saw & matches the requirements of your bar!
(Read this article where I’ve discussed how to choose the right chain for a chainsaw)
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