After each use, turn off the engine then wipe the engine housing and chain bar with a clean rag. Wipe the bar with an oily rag and lightly coat the chain with oil.
Before putting your chainsaw into storage for any amount of time, remove the oil-gas mixture. Run the engine with the choke open until no fuel remains. Cover the chain to protect it from grit.
Consult the owner’s manual for all aspects of care for your particular chain saw.
Also see Caring for Power Equipment for details about engine maintenance.
The chain and guide bar require just as much attention as the engine, if not more. The chain tension must be carefully adjusted; the chain must be properly sharpened; the nose sprocket (if there is one) must be kept greased; and the bar must be inspected regularly for any wear or damage. Neglecting any of these elements will cause the saw to cut incorrectly and, ultimately, to be ruined.
Adjusting Chain Tension
The chain must be kept properly adjusted for efficient cutting. A too-tight chain will overheat and break or damage the bar; a too-loose chain will cut poorly, damage the bar, and possibly fly off the bar.
Because a chain expands slightly as it warms up, adjust the tension only when the chain is cool. To do this, first make sure the ignition is off. Then loosen the bar-mounting nuts so that the chain tension screw can move the bar. Hold the nose of the bar up, then tighten the chain tension screw until the tie straps on each link just touch the bottom of the bar. Pull the chain around several times, holding the nose up all the while. If the tie straps are still just barely touching the bar, tighten the bar-mounting nuts. (If your saw does not have a nose sprocket, there should be enough room for the edge of a dime between the tie straps and the bar bottom.)
The chain will sag slightly when it is warm from use, but it should sag no more than half the depth of the tang in the groove. If it still sags this much after the chain has cooled, retighten the bar-mounting nuts.
The Guide Bar
The guide bar must be inspected and cleaned regularly. Each time you clean the saw, brush out the channel with an old toothbrush. Use a sharpened twig to remove any dirt that’s stuck inside.
To make sure the rails are even and straight, sight down the channels from the nose of the saw. If you see that the rails are spread out at the top, you can hammer them back into shape. Place the bar on a flat, hard surface and put a length of 1 by 4 on the side of the rail. Hammer the wood lightly to bring the rail back in line.
Every time you remove the chain to work on the saw, turn the bar over. This regular rotation will keep the bar from becoming too worn on one side.
If the bar has a nose sprocket, it should be greased each time you use the saw. With a small needle-nose grease gun (available from most chainsaw dealers), pump in grease until you see the grease oozing out around the sprocket.
A final note on preventive maintenance: When the bar is pinched in a cut, never twist and jerk it to get it free. Instead, pry the log up or use wedges.