Replacing a chainsaw chain: A How-to guide
Replacing the chain on your chainsaw is something that is sure to need doing. Learn how to fit a chainsaw replacement chain with our instructions and video guide.
15.10.2024
Overview: replacing a chainsaw chain and other regular maintenance
- Switch off the engine. For cordless models, remove the battery and for electric models, unplug the device. Apply the chain brake
- Wear gloves made from cut-resistant material when replacing your chainsaw chain
- The methods for fitting a cutting attachment are the same across electric, cordless and petrol chainsaws, though the method for replacing the attachment depends on whether your STIHL chainsaw has Quick Chain Tensioning or side chain tensioning
- Refuel your chainsaw on a clean, level surface
- Do not fill the chain oil or fuel tank right to the top
Replacing a chainsaw chain: safety first
Ensure that the chainsaw is switched off and cannot start up during assembly:
- For a cordless chainsaw, remove the battery and apply the chain brake.
- For an electric chainsaw, remove the plug from the socket and apply the chain brake.
- For a petrol chainsaw, switch off the engine and turn the combi lever to 0. Apply the chain brake.
- Always wear work gloves made from robust material.
Replacing a chainsaw chain: cutting attachment installation
When replacing a chainsaw chain, you want to make sure the chainsaw chain direction remains correct. The method for fitting a cutting attachment is the same for electric, cordless and petrol chainsaws. The only difference is in the individual steps related to the tensioning device with which your STIHL chainsaw is equipped.
Replacing a chain on a chainsaw with Quick Chain Tensioning
Fitting the cutting attachment is particularly quick and convenient on STIHL chainsaws that have Quick Chain Tensioning, and requires virtually no tools – just a flat head screwdriver.
Here's how it works:
Fold out the handle of the wingnut and turn it anti-clockwise until you can remove the chain sprocket cover.
Take out the tensioning gear and turn it over so you can access the screw on the back. Take the screw out.
Release the chain brake by pulling the chain brake handle towards you.
Place the guide bar onto the tensioning gear so that the two pins of the tensioning gear sit in the boreholes on the guide bar. The orientation of the guide bar is not important – it doesn’t even matter if the lettering on the guide bar is facing the wrong way. Replace the screw and tighten it.
Make you are using a suitable guide bar and saw chain combination as indicated in the operating instructions. To make sure your chainsaw chain direction is correct, place the saw chain into the groove of the guide bar, working downwards from the bar nose, checking that the arrows on the connecting links of the chain are pointing in the direction of rotation. Turn the tensioning gear clockwise as far as possible.
Turn the guide bar so that the tensioning gear faces outward. Place the saw chain onto the sprocket; the drive links of the chain should sit into the teeth of the sprocket as you do this.
Position the guide bar on the chainsaw and slide it over the collar screw. Guide the drive link into the bar groove and turn the tensioning gear anti-clockwise as far as possible.
To secure the chain sprocket cover, push the guide pins into the openings in the engine casing. Turn the wing nut clockwise until the cover is firmly attached to the chainsaw.
Lift the chainsaw guide bar by the tip a little so that the chain sags slightly. Tighten the chain by turning the adjustment wheel clockwise as far as it will go. The chain should now be close to the bar; the distance between chain and bar should be 1–2 mm in the middle of the guide bar.
You will find more helpful tips in our instructions for tightening your chainsaw chain.
Finish by tightening the wingnut by hand and then fold the handle in.
Replacing a chain on a chainsaw with side-mounted chain tensioning
The side-mounted tensioner is widely used in many electric, cordless and petrol chainsaws. It offers convenient access to the chain tensioning components and also reduces the risk of contact with hot engine components.
Here's how it works:
Use a combination socket tool to loosen the fixing nut or nuts on the chain sprocket cover so you can remove it.
To release the chain brake, pull the chain brake handle backward until it clicks.
Now that the tensioning plate is visible, turn the tensioning screw anti-clockwise until the tensioner slide is all the way to the left.
Make you are using a suitable guide bar and saw chain combination as indicated in the operating instructions. To make sure your chainsaw chain direction is correct, place the saw chain into the groove of the guide bar, working downwards from the bar nose, checking that the arrows on the connecting links of the chain are pointing in the direction of rotation.
Turn the guide bar into position facing the tensioning plate. Place the saw chain onto the sprocket; the drive links of the chain should sit into the teeth of the sprocket as you do this.
Replace the sprocket cover on the engine housing. Hand-tighten the nut.
Lift the tip of the guide bar so that the chain sags slightly, turning the tensioning screw clockwise as far as it will go. The chain should now be close to the bar; the distance between chain and bar should be 1–2 mm in the middle of the guide bar.
You will find more helpful tips in our instructions for tightening your chainsaw chain.
Finally, tighten the nut using the combination socket tool.
Chainsaw replacement chain tension: Front chain tensioning
The tension adjustment screw is usually located on the side, however there are a few models, where it is located on the front. The method for adjusting the tension is the same as for side-mounted tensioners.
To access and mount the bar and chain, remove the nuts with a socket tool and remove the sprocket cover.
To release the chain brake, pull the chain brake handle backward until it clicks.
Now that the tensioning plate is visible, turn the tensioning screw anti-clockwise until the tensioner slide is all the way to the left.
Make you are using a suitable guide bar and saw chain combination as indicated in the operating instructions. To make sure your chainsaw chain direction is correct, place the saw chain into the groove of the guide bar, working downwards from the bar nose, checking that the arrows on the connecting links of the chain are pointing in the direction of rotation.
Turn the guide bar into position facing the tensioning plate. Place the saw chain onto the sprocket; the drive links of the chain should sit into the teeth of the sprocket as you do this.
Position the pin of the tensioning slide in the lower mounting hole of the bar.
Replace the sprocket cover on the engine housing. Hand-tighten the nut.
Lift the tip of the guide bar so that the chain sags slightly, turning the tensioning screw clockwise until the chain is very close to the bar; the distance between chain and bar should be 1–2 mm in the middle of the guide bar.
Finally, tighten the nut using the combination socket tool.
After replacing the chain: topping-up chain oil in your chainsaw
All petrol, cordless and electric chainsaws must be filled with high-quality chain oil to ensure that the saw chain and guide bar are always lubricated and cooled. Doing this reduces wear on the chain and extends the service life of your cutting attachment. The process is the same for chainsaws of all drive types. If you have a petrol tool, you should top up the chain oil every time you fill up with petrol. For cordless and electric chainsaws, check the tank regularly and refill it as needed. Some STIHL chainsaws have a window on the tank that helps you to check the fill level.
Fuel caps
STIHL chainsaws either have a conventional screw-on fuel cap or a toolless fuel tank cap. The process described here is for using and replacing a screw-on cap; if you have toolless tank caps, we have put together separate detailed information about opening and replacing tool-free fuel caps.
How to fill your chainsaw with chain oil:
Place the chainsaw on a level surface so that the tank cap is facing up. Clean the area around the fuel cap with a damp cloth to ensure that no dirt gets into the tank.
Turn the fuel cap anti-clockwise and remove it.
Pour chain oil into the oil tank, taking care not to spill it. Make sure you do not fill the tank all the way to the top. We recommend you use the STIHL filling system to make this easy.
Replace the cap and turn it clockwise until it is tight. The chain oil tank is now securely closed.
Petrol chainsaw fuel mix
Your chainsaw needs the right fuel mix and filling process to keep it performing at its best and to ensure your safety.
Safety when refuelling
- Petrol is extremely flammable. You should always maintain a safe distance from any naked flames when refuelling your chainsaw, avoid spilling fuel and do not smoke in the area. Chainsaw refuelling should always be done at least 3 metres from the working area in which you will be starting your chainsaw.
- Switch the engine off completely before filling the fuel tank; you should not refuel while the motor is hot.
- Open the fuel cap carefully to allow any overpressure to dissipate gradually and to ensure that no fuel sprays out of the tank.
- You should only ever refuel a chainsaw in a well-ventilated area.
- Make sure that you do not spill any fuel on the tool or your clothes. If you do spill fuel, you must immediately clean the chainsaw and change your clothes.
How to fill a petrol chainsaw with fuel mix
Find out how to fill your chainsaw with mixed fuel.
Find a clean, level surface for refuelling your chainsaw. Position the chainsaw so that the fuel tank cap is facing up. Clean the cap and the area around it with a cloth so that no dirt falls into the tank.
These instructions describe the process for a tool-free fuel tank cap. If your chainsaw has a screw-on fuel cap, follow the same steps as given above for filling chain oil.
Flip out the handle on the cap and turn it clockwise to remove it.
Fill the fuel tank slowly and carefully. Take care not to spill the fuel and do not fill the tank up to the very top. The STIHL filling system for fuel makes it especially easy to refuel your chainsaw.
Replace the cap so that the markings on the lid and the fuel tank match up, and push it down. Turn the cap anti-clockwise as far as it will go and flip the handle back in. Are the markings aligned? If so, the tank is securely closed.
Your STIHL dealer is always happy to support you by preparing your chainsaw for use.
After replacing and fuelling, you're ready to go: Our article tells you how to start your chainsaw.
