Why Your Chainsaw Is Smoking and Burning Wood

Is your chainsaw causing the wood you are cutting to smoke or even leaving scorch marks on the face of cut logs? The issue of a chainsaw burning wood is more common than you might think, and it is likely the result of a dull chain, high rakers, a chain put on backward, or a problem with bar oiler. In this article, we will discuss these common causes of a chainsaw burning wood and producing smoke and how to diagnose and fix the issue. Stick with us, and you will be back out cutting in no time!

A Dull Chain Will Cause Wood to Smoke and Burn

The most common cause of smoking and burning wood is undoubtedly a dull chain, and it happens to the best of us. Chainsaws produce a tremendous amount of heat as they cut. Under normal circumstances, a sharp chain will cut away wood before that heat has a chance to build up, but if a chain is dull, the heat will build up quickly, causing the wood to smoke and eventually burn before the chainsaw makes its way completely through the tree. If this is the case, sharpening your chainsaw will alleviate the problem entirely. Be sure to keep your chain sharp!

How to Check if Your Chain is Dull

There are a few easy ways to check if your chainsaw needs to be sharpened:

1. A well-sharpened chain should be producing larger chips of wood. A chainsaw chain works like a chisel, stripping wood away–not grinding it. If the chainsaw is producing chips that resemble saw dust more than solid chunks, it is likely the saw is dull.
2. A chainsaw should be cutting through wood relatively easily. If you find yourself having to apply excessive pressure or working the chainsaw to get it to cut through, the chainsaw is probably dull. That said, there are certain species of wood, such as oak and hickory, that will naturally be tougher to cut through than softer species.
3. If a chainsaw is excessively dull, you can usually tell through visual inspection. The cutting edges will appear more rounded, which is indicative of a chain in need of sharpening.
4. If in the process of cutting, your chainsaw came in contact with the ground (even if for just a second), the chain will need to be sharpened. Rocks and sand in the dirt will dull your chain in an instant!

Your Rakers Are Too High

Sharpening isn’t the only regular maintenance you need to be doing to your chain, you also need to be filing your rakers to ensure a proper cutting depth. Rakers are the bits of metal in front of the tooth that keep the cutting depth consistent. As you can see from the diagram below, the teeth of a chainsaw are produced from a downward-sloping angle. As the tooth is gradually filed away from repeated sharpening, the overall height of the tooth is reduced until the raker obscures it entirely. When this happens, the saw will be virtually unable to cut, even if the chain itself is well-sharpened. This can cause a massive amount of heat to build up and result in your chainsaw burning wood and smoking from the heat produced from the friction.

To resolve this issue, you must file down the rakers to create a proper cutting depth of .025″. The use of a depth gauge is required to get proper and consistent depth. Every time you sharpen your chainsaw, it is good practice to check your rakers with a depth gauge to ensure your saw will cut quickly and efficiently–and without smoke!

To learn how to properly file your rakers, we have an article on the subject here.

Did You Put the Chain on Backward?

An embarrassing yet extremely common cause of a chainsaw producing smoke and burning wood is a chain put on backward. A chain should be configured so the cutting face of each tooth is facing away from the chainsaw operator on the top of the bar and toward the chainsaw operator on the bottom of the bar, such as in the photo below:

Putting your chain on on backward can make you feel silly, but luckily it is an easy fix! Simply take the chain off and put it back on correctly. And don’t worry, we have all been there. There are only two types of chainsaw owners in this world: Those who have put their chain on backward and those who are liars.

Problems With the Chainsaw Oiler

One of the more frustrating and problematic causes of a chainsaw burning wood and producing smoke is a problem with the saw’s oiler system. Chains require a constant feed of lubrication, and when the lubrication stops, it can cause all sorts of problems. If your chainsaw is having problems feeding oil, the problems will go beyond a little smoke. The bar could become discolored from the high amount of heat, and the chain may become loose from the thermal expansion, creating occasional sparks and perhaps even causing the chain the jump off the sprocket (always wear your gear). This is a substantial problem that needs to be resolved as quickly as possible, and you should refrain from running your saw until it is repaired.

Check Your Chainsaw’s Oil Supply

If you suspect the problem may be related to the saw’s oil system, the first thing you should do is check the levels of bar oil. If the chainsaw is out of bar oil, you have found your problem. Simply refill the oil chamber and remember to refill the oil every time you fill up with gas.

If the bar oil is full, then check to see if the oil is making it to the bar. There are two ways to check this:

1. Gently pull the chain up from the bar and see if the underside of the bar looks lubricated.
2. put the tip up the bar a few inches away from the end of a log (not touching it) and rev the throttle a couple times to allow the chain to spin. If the oiler is working, there should be a visible line of oil spray on the log that came off the chain.

If it looks like no oil is getting to the chain, then you have found your problem.

How to Fix a Chainsaw Oiler That Is Not Dispensing Oil

The most common cause of a malfunctioning oiler is blockage. With so much sawdust produced from using a chainsaw, it is incredibly normal for material to occasionally build up and cause some blockage. Luckily, this is also easy to fix.

Simply remove your bar and clean any debris from the oil dispenser on the chainsaw itself and the oil hole of the bar. This is a task that should be included in your regular chainsaw maintenance.

If there is no debris causing blockage, then the likely problem is a broken oiler or stripped gear.

There are several gears that play a role in bringing oil to the bar. On certain models of chainsaw, these gears can be made of plastic and strip or melt fairly easily. You will have to remove the clutch and inspect the parts individually, replacing broken parts as necessary. Take the saw to your local repair shop for assistance.

For a more detailed article on fixing this issue, you can read our article here.

Get Back to Cutting!

Chainsaws burning wood and producing smoke is a fairly common problem, and it is usually an easy problem to fix. Once you correctly diagnose the issue and implement the solution, it’s time to get back to cutting! Have fun, and don’t forget your chaps!