Your chainsaw will either require you to adjust the chain tension manually with a socket spanner or screwdriver (usually supplied) or it may have manual tool-less chain tensioning, operated with a dial or lever.
There are a very few models with fully automatic chain tensioning. If this is fitted, all you need do is carry out though a thorough check before every.
If your Chainsaw has manual ‘tool-less’ tensioning, you will have to adjust it yourself.
The instruction manual of your Chainsaw will contain guidance in how to adjust the tension of your chain, but we have included some basic, generic instructions below:
N.B. Make sure you are wearing protective gloves before you carry out this procedure.
Manual tooled chain tensioning
1.Make sure the chainsaw is sitting on its base, and then loosen the nuts fixing the guide bar to the engine mount.
2.Lift up the end (the ‘nose’) of your guide bar.
3.With guide bar nose lifted, rotate the tensioning screw, which you will usually find on the front of the saw near the point at which the chain is attached. Use a screwdriver or purpose made tool to adjust the screw.
Clockwise - increases the tension
Anti-Clockwise - decreases the tension.
On some chainsaws these the tensioning screw can be reached without removing the cover screws, as in the image below.
image courtesy of Stihl
You will know the chain is at the correct tension when it fits closely all the way round but you can still move it slightly away with your hand.
Top chain guide bar and chain manufacturer Oregon suggest that if you have a drive-sprocket nose bar, you then try the ‘snap test’. Grip the chain along the bottom of the bar, pull down and let go. Your chain should ‘snap’ back against the bar, it’s position, clicking into position along the bar rail.
Here is an illustration to demonstrate the correct and incorrect chain position.
image courtesy of Oregon
4.Finally, re-tighten the fixing nuts and you should be ready to go.
Manual toolless chain tensioning
1.Make sure the chainsaw is sitting on its base
2.Using the manufacturers dial or switch turn clockwise to increase tension and anti-clockwise to de-crease tension (see image below)
3.Check as above
image courtesy of Stihl
NB: NEVER ADJUST THE CHAIN WHILE IT IS HOT. IF YOU ADJUST IT AFTER USE, ALWAYS WAIT UNTIL IT HAS COMPLETELY COOLED.