Adjusting The Chain Tension - Craftsman S145 Manual Del Operador

ADJUSTING THE CHAIN TENSION

CAUTION:
The guide bar, saw chain, and saw bearings
will wear more rapidly if the saw chain is not properly
tensioned. Maintaining proper chain tension will improve
cutting performance and prolong the life of the saw chain.
WARNING:
To prevent serious injury, never touch the
saw chain or adjust the chain tension while the unit is
running. Disconnect the spark plug wire to prevent the unit
from starting accidentally.
WARNING:
The saw chain is very sharp. Always wear
heavy-duty protective gloves when handling or performing
maintenance on the saw chain.
Check the chain tension before and during operation. The saw chain
will expand as it heats up during operation. Adjust the chain tension
whenever the flats on the saw chain hang out of the bar groove (Fig.
25 and Fig. 26).
NOTE: A new saw chain tends to stretch and will need readjustment
after as few as five (5) cuts. This is normal during the break-in
period. The interval between future adjustments will lengthen
quickly.
1. Make sure the chain brake is disengaged. Refer to Testing the
Chain Brake in the Assembly section.
2. Use the multi-purpose tool or a 1/2 inch (13 mm) wrench to
slightly loosen the bar-retaining nuts (Fig. 27). DO NOT remove
the bar cover.
3. Hold the guide bar tip up and use a flat-head screwdriver to turn
the chain-tensioning screw (Fig. 27).
• Turn the chain-tensioning screw clockwise to tighten the saw
chain.
• Turn the chain-tensioning screw counterclockwise to loosen
the saw chain.
The saw chain should fit snuggly against the underside of the
guide bar. There should be no sag (Fig. 26).
4. Continue to hold the guide bar tip up and move the saw chain
back and forth along the guide bar (Fig. 28). Make sure the saw
chain moves freely and is in proper mesh with the sprocket. If
the saw chain does not move easily, slowly turn the chain-
tensioning screw counterclockwise to loosen the saw chain.
NOTE: The saw chain will not move if the chain brake is engaged.
5. Continue to hold the guide bar tip up and securely tighten the
bar-retaining nuts.
CAUTION:
If the saw chain was tensioned while warm, it
may become too tight when cooled. Loosen the chain
tension after operation and check the chain tension before
the next use.
Correct Tension
Incorrect Tension
21
Flats Guide Bar
Fig. 25
Fig. 26
Bar-Retaining Nuts
Guide Bar Tip
Bar Cover
Chain-Tensioning Screw
Fig. 27
Fig. 28