Check the chains for excessive wear, and replace when necessary.
Inspect the drive links, sprockets, cutters and track for damage:
Repair or replace badly hammered links.
If cutters need replacing, file them to the same length as the existing cutters.
Replace the bar if nicked or distorted.
Replace bar and chain if the bar is damaged.
Replace worn or damaged drive sprocket before it damages the chain.
Use the proper size files to sharpen the chain. Two files are necessary:
a flat file for adjusting depth gauge
a round file of uniform diameter for sharpening cutters and maintaining drive links
Check depth gauges every third of fourth time you sharpen the chain.
Adjust the tension of the saw chain after it has been in use for five to ten minutes. The chain stretches as it heats up and requires adjustments at intervals throughout its operation. Do not adjust tension or replace chain while the chain is hot. Damage to the guide bar or crankshaft can occur when an overly tightened chain cools.