The Snap Test: Wearing gloves and goggles, hold onto the top of the saw. With the other hand, lift the chain off the bar (near the mid-point of the bar) slightly and let go. If it doesn’t snap back into place cleanly, you’ll need to adjust the tension. For precise work, you want about a 1. 25mm space between the blade and the bottom of the bar when the motor is cool. A hot motor and chain will slightly expand the chain, loosening it slightly.
Some smaller saws may have a knob or lever to release the cover, instead of screws or nuts, making it easier to adjust without tools.
A toothbrush is a good way to help remove tricky, hard-to-reach bits.
Not all guide bars include a roller tip and not all roller tips require additional grease. Follow the operating instructions for your particular saw. If you’re adding a new chain and want to adjust it, click here. If you simply need to tighten your old chain, click here.
If the edges of the guide bar have become flared from heavy use, they may interfere with the smooth cutting of the chain, making it difficult to cut straight, if at all. If the edges or the grooves become worn, it may be time for a replacement guide bar. While the chain is off the saw, check the saw’s drive sprocket for excessive wear. It is not unusual to need a new drive sprocket after wearing out multiple chains.
With some types of sprockets, you may need to insert the bar without the chain on it, then loop the chain around the drive sprocket, finishing up by aligning the chain loosely into the groove on the guide bar.
Do not completely tighten the attachment nuts yet because they serve to clamp the bar into position, and it needs to be adjusted first.
Sometimes the adjustment screw is located between the mounting studs. It could also be on the outside of the chainsaw, on the bar cover or on the engine. [5] X Research source
A “perfect” middle ground to shoot for is 1. 25mm of space between the chain and the bar, on the bottom half.
