19
Fig. 27
Correct Warm Tension
Too Loose
Correct Cold Tension
ADJUSTING THE CHAIN TENSION
Check the chain tension before and during operation. Adjust the
chain tension whenever the flats on the saw chain hang out of the
bar groove (Fig. 25).
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. 26).
3. Hold the guide bar tip up and use a flat-head screwdriver to turn
the chain-tensioning screw (Fig. 26).
• Turn the chain-tensioning screw clockwise to tighten the saw
chain.
• Turn the chain-tensioning screw counterclockwise to loosen
the saw chain.
The desired chain tension depends upon the temperature of the
saw chain (Fig. 27).
• Cold Chain Tensioning - The saw chain should fit snuggly
against the underside of the guide bar. There should be no sag
(Fig. 27).
• Warm Chain Tensioning - The saw chain will expand as it
heats up during operation. The drive links should hang
approximately 1/16 inch (1.3 mm) out of the guide bar groove
(Fig. 27).
4. 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. Hold the guide bar tip up and securely tighten the bar-retaining nuts.
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.
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.
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.
Fig. 25
Flats
Fig. 26
Bar-Retaining Nuts
Guide Bar Tip
Drive Links
Guide Bar
Chain-Tensioning Screw
Fig. 28
Содержание RM4618
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