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Chainsaw Cuts Out When the Chain Brake Is On: 5 Fixes

Chainsaw Cuts Out When the Chain Brake Is On: 5 Fixes

Your chainsaw brake keeps you safe and prevents any kind of kickback (i.e., when you cut into something like a piece of wood, and it moves back at you). But when it malfunctions, you may be tempted to remove your chain brake altogether. There are better ways to deal with the problem, though.

If your chainsaw cuts out when the chain brake is on, you may need to replace your drums, bearings, or sprockets. Additionally, an air leak or misalignment on the chainsaw bar might affect your chainsaw functioning. You can also lubricate your chainsaw to see if this helps. 

Your chainsaw won’t work well (not to mention become pretty dangerous) if the brake is defective. Luckily, it’s pretty easy to fix. Below, I’ll explain in more detail what your chain brake does, the common reasons it malfunctions, and tips on fixing these malfunctions. 

Your Chain Brake Explained

As I’ve mentioned earlier, the chain brake is a safety feature that prevents your chainsaw from flying up into the air and hitting you in the face (source). A chain brake is supposed to help you with kickback. It’s located on the upper part of your saw, so it’s fairly easy to find.

This video shows where it’s located and how it works:

Chainbreak system by STIHL: the safety feature protecting you against kickback

When using your chainsaw, ensure that the chain brake is engaged (i.e., turned toward you). If it isn’t, turn it around so that it points toward yourself. You’ll see a small lever between two pieces of metal on top of your saw’s engine housing. 

Now that you know what the chain brake is, what it’s used for, and how to find it, let’s get into the most common problems chainsaw brakes experience and how you can fix them.  

1. Worn Drums, Bearings, or Sprockets

First, you must check if a broken chain brake is causing the malfunction (source). It’s possible that other parts may be to blame. Start checking the drums, followed by the bearings, and then the sprockets. 

This video shows how this system functions and how to fix the issue:

Stihl Chainbrake Repair :How To (Ground Saw)

How To Fix It

If any of the items I mentioned above look worn, broken, rusty, cracked, chipped, or the like, it’s time to replace them. You can usually find parts online or in your local hardware store. 

Also, here are a couple of things you can do to ensure your chain brake is working properly. 

  • Check for tension on the sprocket side of your bar. If there’s too much tension, loosen it. If there’s too little, tighten it until there’s a slight gap between each tooth on both sides of its track.
  • Ensure that your bar has been properly greased or oiled before use. This way, dirt doesn’t get into any moving parts. Otherwise, they’ll malfunction over time due to friction caused by dust buildup.

2. Your Chainsaw Needs Lubrication

Lubricating the chain before you start cutting is important. If you don’t do this, it can damage your saw and cause things like the chain brake and chain to start acting up. 

How To Fix It

Make sure you have the right oil, and change it regularly (source). Also, check your chain tension regularly. You can do this by pulling the bar towards the front of the saw while holding it down firmly on top of an old rag to catch any falling debris or oil drips.

3. Chainsaw Bar Is Not Aligned

Again, the chain brake is a safety feature that keeps the chain from rotating if it breaks or becomes loose. It also works to prevent kickback by stopping the rotation of the blade when misaligned (source). If your chainsaw bar isn’t aligned, the chain brake won’t work.

Other signs of a misaligned chainsaw bar are:

  • The chainsaw doesn’t cut straight. Put another way, the chainsaw cuts off at an angle. This happens when the chain is misaligned with the bar on your saw.
  • The chain seems to bind up or jump around while cutting. This happens because the chain isn’t aligned with the bar and is cutting unevenly across the face of the blade, which causes friction and vibration in the chain.
  • You hear a rattling sound when you’re cutting through the wood. This is usually caused by a loose chain or a bent bar that doesn’t properly support the teeth on your chainsaw’s chain as they pass through each other during use. If you’ve recently dropped your chainsaw, this is the most likely issue.
  • Your saw starts smoking. This happens when too much heat builds up inside it due to friction between parts that aren’t properly aligned with one another like those described above.
  • Your saw stalls out more often than usual. This may mean something inside has jammed up against another part because everything wasn’t properly aligned. 

How To Fix It

Try loosening the bolt on the bar and tilting it back. Make sure you don’t apply too much pressure, or you could damage the engine. Once you have realigned the bar, tighten up the bolt and ensure it doesn’t move anymore. This can take a while to do, but it’s worth the benefit of having a chainsaw that’s safe to use. 

4. Clutch Springs or Clutch Clips Need Replacing

If your chainsaw is cutting out when the chain brake is on and you can’t find a spring, or if you have removed the spring, the clutch spring may need replacing. The process for replacing this part varies depending on which chainsaw model you have, though there are general steps you can follow. 

How To Fix It

To replace a broken clutch spring:

  1. Remove all the screws holding down your cover plate and take off the cover plate.
  2. Locate where your clutch spring goes by looking at how it was originally positioned in your chain brake system. It will probably be connected as part of a plastic rod.
  3. Slide one end of another new spring onto this plastic rod while sliding its other end into place behind where its original counterpart connected with other parts inside the motor housing. Check that both ends are firmly connected before reassembling everything else.

This video gives a visual of this process:

Chainsaw Clutch Spring replacement, STIHL 029 super

Of course, if this sounds a little too intimidating for you, a certified dealer should be able to help you out.

5. An Air Leak

If your chain brake is on and the chain stops turning when you bring the saw to a stop, there may be an air leak. That’s because a chain brake creates back pressure in the oil lines that run from the tank to your engine. 

If there are any leaks in these lines and/or fittings on either end, this back pressure will find a way out, and that can lead to your chainsaw not cutting properly.

How To Fix It

The air filter is going to be your target for this fix. 

Specifically, here’s a step-by-step guide on fixing air leak issues with your chainsaw. 

  1. Remove the air filter screen from your saw by removing the screws.
  2. Clean any debris or dirt inside the filter housing with a cloth or paper towel soaked in degreaser and warm water. Be sure to wipe away any excess cleaner, so it doesn’t run through into other parts of the machine.
  3. Check for holes or tears in the filter media. If there’s any damage there, replace it with a new one made specifically for your chainsaw model. You should be able to find these at any hardware store.
  4. Reinstall your new filter screen into its housing and screw it back into place using a small screwdriver or Allen wrench. The size depends on how many screws came with your machine. Make sure not to overtighten these screws, or they may strip out over time.


If you’ve been having trouble with your chainsaw cutting out when the chain brake is on, you may have a problem with it or the parts around it. Regular preventative maintenance, such as lubricating your chainsaw, tightening pieces, and watching tension, should help keep your chainsaw running smoothly.

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