Is Your Chainsaw Sparking? Try This!


It has happened to all of us: We go to cut a log and our chain starts throwing sparks like a musket. If it is happening to you, don’t worry. There are a few common reasons why the chainsaw may be sparking, and the majority of them are quick fixes. In most cases, it is nothing but a mild annoyance as it adds extra wear to the chain, but it is best to prevent it if possible. In this article we we go over the reasons why your chainsaw may be sparking, its impact on the saw, and how you can best prevent it. These reasons are:

  • Hitting the dirt
  • Applying an angled pressure on the saw
  • Dirty bark
  • Hidden metal in the tree
  • Improper chain tension
  • Malfunctioning oiler

Let’s dive in to these issues and their solutions.

Sparking chainsaw dogs.

Hitting Dirt Will Cause Sparking

The most common reason for a chainsaw sparking from the chain is operator error. Namely, you keep hitting the dirt. This is causing the chain to hit rocks and spark as a result of the impact. The solution is simply to control your saw better and be more careful when operating close to the ground.

If this is your problem, we have an article about what to do when your chainsaw hits the ground and how to better prevent it. Give it a read here. This happens on occasion to even the most experienced sawyers, so don’t sweat it. That said, it is important you properly inspect your chain and sharpen it after such an occurance and do your best to prevent it from happening again. Chainsaws were meant to cut wood, not rocks.

Angled Pressure on the Saw

Another common source of sparks from user error is the pressure on the saw exerted by the sawyer. A properly tuned and sharpened saw should be doing all the work. The duty of a sawyer is simply to control the power of the saw. If you find your self exerting pressure on the saw at an angle, it could be causing misalignment with the chain, sprocket, and bar groove, creating sparks as the chain contacts the bar in ways it was not intended to.

The angle of a cut should always be established prior to cutting, after the cut is underway, the saw is not designed to adjust direction. If you find the saw cutting at an angle, it is likely due to inconsistently sharpened angles on the teeth of the bar. Always use a gauge to ensure you are sharpening at proper and consistent angles. You can find one here.

Is the Log the Problem?

It is entirely possible your chainsaw is sparking not because of anything wrong with the saw or your technique but because of the log (or log pile) you are trying to cut. The wood could either be dirty or hiding a piece of metal within the stem.

Dirty Logs

Dirty logs is the name of the game in forestry. During the harvest process, it is common for forest machines like skidders to drag logs across the forest floor, and during certain times of the year, the forest floor is little more than mud. If a tree has bark with deep fissures (such as sugar maple or white pine) these fissures can become absolutely caked with rocks and dirt, which will produce a similar effect as hitting the dirt with your saw. Unfortunately, once the log is dirty, there is little that can be done to clean it, unless you want to take the time to pressure wash your logs. That may be worth it if you plan to mill your logs, as bandsaws can be even more sensitive to these rocks than chainsaws, but it otherwise probably is not worth the effort. Sparking on part of the chainsaw is just a normal part of wear and tear–just be sure to wear your safety glasses and face shield in case any rocks come flying up!

The best solution to prevent dirty logs is to take more care in the felling and transport of them, if you have any control over the process. The best time to harvest timber is the winter, as ice and snow provides a clean medium that prevents bark from becoming caked in mud. It also prevents staining in certain stain-prone species like maple and white pine. If harvesting in winter is not an option, moving wood in such a way that keeps them off the ground, such as by using a forwarder or timber trailer, may be a preferable option.

Wood from a messy or muddy harvest can cause sparking from a chainsaw from rocks that get stuck in the crevices of bark.

Hidden Metal

Another big reason a log may be causing a chainsaw to throw sparks is that the log contains overgrown metal. This is incredibly common in woods around old farms or woods that have been used and harvested for centuries, which is the norm for small woodlots used for firewood production and the like.

As trees grow, they have a tendency to pick up and absorb metal from the surrounding area. In some cases, it is barbed wire fence the tree grew around, but in other cases, larger objects like horseshoes can become lodged in the growth of the tree. I imagine these extreme scenarios are the result of anomalies, such as kids playing a game of horse shoe with a tree back in the day, but there are more common and more explainable occurrences. Abandoned maple taps and bullets are both common finds for irritated sawyers, and both can wreak real having a chain–often with a grand finale of sparking. If you cut wood from a woodlot with, shall we say, a lot of history, perhaps it would be wise to invest in a metal detector to try to find these chunks of metal before they create a bigger headache.

Check the Tension on the Chain

If the log is not the problem, and the chainsaw is repeatedly sparking, the next step would be to check the chain tension. If a chain is either too tight or too loose, it can cause sparks.

A chain that is too loose will have too much uncontrolled motion, often lifting up off the bar and losing contact with the sprocket. This can cause the metal to create sparks as it comes back in contact with bar and metal contacts metal at high speeds. Alternatively, if a chain is too tight, too much friction can be produced, and heat can build up, oil can burn off, and metal can come in contact with raw metal, leading to a fireworks show of sparking.

To check your saw tension, simply pull down on the chain (with the saw OFF) and release. A properly tensioned saw should be able to pull out about a half inch or so and then firmly (but not violently) snap back into position. To read more about tensioning your chainsaw chain, check out this article here.

A chain can also spark from too much or too little chain tension.

Is the Oiler Working?

This problem can be a bit more difficult to fix, and it can happen in tandem with issues with a saw retaining tension. If the oiler is not properly lubricating the chain, it can lead to a massive increase in friction, heat, and expansion in the bar and chain. These problems can present as a whole array of other issues, including the chain becoming too loose or too tight, discoloration of the bar, scorching and smoking the wood you are cutting, and, of course, causing a great deal of sparking from the chainsaw.

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. Inspect the oil ducts to ensure there is no blockage, and if all looks clear move on to inspect the gear system of the oiler itself. If all else fails, bring your saw into a local repair shop for assistance.

Conclusion

Sparks are produced when two objects of comparable density collide energetically. Because a chainsaw is designed to cut through wood with a steel chain, sparking is indicative of a problem. That said, sparks here and there are a normal part of wear and tear on a chain. As long as you are consistently sharpening your chain, it won’t be too much of a problem, aside from dulling out your chain faster. However, if you find your chainsaw is sparking freaking or violently (something on the scale of a 4th of July sparkler, it is a major problem. Stop cutting immediately, turn the saw off, and inspect for any issues, using the information here as a guide. Good luck, and as always, stay safe!

Zachary Lowry

Working as a professional forester in northern Maine, I quickly saw the opportunities within the forest industry for small-time investors and woodlot owners. I started The TImberland Investor to bring these insights and opportunities to you.

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