Not only does a slow-moving chain cause your chainsaw to underperform. It may cause additional damage to the saw if it isn’t addressed.
A chainsaw chain won’t turn or move when the chain brake is activated, the chain tension is too tight, the clutch pads are worn, or the bar and chain are not sufficiently lubricated.
Before checking the bar and chain, turn off the saw, remove the spark plug boot, and wait for all parts to stop moving. Wear heavy safety gloves and follow all safety precautions listed in the operator’s manual.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
Reasons a Chainsaw Chain Won’t Turn, Move or Rotate
Chain Brake Activated
You will have a plastic hand guard placed in front of the handle on a chainsaw. This guard is used to protect the user when the saw kicks up and back at the user.
The chain brake is designed to engage and stop the chain from turning in the event this happens. It also stops the chain from moving when it is pushed forward.
Check the hand guard to make sure it isn’t pushed forward activating the chain brake. You may have accidentally pushed it forward causing the chain to stop. Pull the guard to the rear to disengage the brake.
Lack of Bar and Chain Oil
The bar and chain must be kept lubricated to avoid friction and heat buildup that may cause the chain to begin moving slowly around the chain.
To check for sufficient oil on the bar, run your chainsaw at about 1/2 – 3/4 throttle while holding it about a foot off the ground. Look for a line of oil coming off the bar and appearing on the ground after about 30 seconds. This will indicate proper lubrication.
If you aren’t getting good lubrication, make sure the bar is in good condition and the oil channel isn’t blocked. Clean the oil channel and replace a worn or damaged guide bar.
Make sure the bar and chain are well lubricated with oil like premium bar and chain oil like the oils offered by STIHL, Husqvarna, and ECHO.
Refill the bar and chain oil every time you fill up with fuel so you don’t run out. Note: If you are running too thin of oil, you may run out of chain oil before it’s time to refill the fuel tank.
Change the Bar and Chain Oil with the Ambient Temperature
- Thinner oil for cold temperatures: Oil will thicken and become tackier in cold temperatures. Look for oils often sold as low-temperature or winter bar and chain oil.
- Standard weight for warmer temperatures
Chain Tension is Too Tight
The chain should be adjusted regularly as it will become a little longer the more you use it. When the chain is too tight, it will not rotate around the bar.
Adjust the chain tension so it easily moves around the chainsaw bar:
- Remove the spark plug wire.
- Unlock the chain brake.
- Loosen the bar retaining nuts that hold on the cover over the clutch and chain brake.
- Hold the nose of the bar up.
- Turn the tensioning screw counter-clockwise to loosen the chain and clockwise to tighten the chain.
- Once you achieve the correct tension, tighten the bar retaining nuts while continuing to hold the bar nose up.
You want the chain to sit securely around the bar, but still able to move easily. You don’t want it so loose that it hangs from the guide bar.
Worn Clutch Pads
The clutch pads can wear with time. When this happens, they won’t engage the clutch drum to turn the chain. The clutch assembly will need to be replaced.
Reasons a Chain Moves at Idle Speed on a Chainsaw
Carburetor Needs Adjustment
A chain should not move when the chainsaw is idling. If yours does, you need to adjust the saw to stop the chain from moving.
There are adjustment screws on the carburetor that adjust the mixture of fuel to air. One of the adjustment screws, the “idle screw” adjusts the idle speed affecting chain movement.
Adjust idle speed so the chain doesn’t move while idling begins by turning the screw counter-clockwise just until the chain stops moving. Then continue 1/4 turn further.
Worn Clutch Springs
On a chainsaw centrifugal clutch, there are springs that retract the clutch weights. When the engine speeds up, the centrifugal force pushes the weights outward making contact with the drum. The drum spins making the chain move on the bar.
When the engine slows down, the spring retracts the clutch weights and the chain is supposed to stop moving. If your chain continues to move, you may have a worn spring that needs to be replaced.
Still Having Troubles With Your Chainsaw?
As a chainsaw owner, you’re going to run into problems with it occasionally. This is true of all chainsaws.
To help you quickly identify the cause of your problem and how to fix it, I’ve put together a handy reference guide.
You will find charts with problems and solutions to many common issues along with links to information in more detail.
Check out Common Chainsaw Problems for help solving problems with your equipment not starting, the chain not turning, the engine dying, a loss of power, and more.