Craftsman S145 Operator's Manual page 24

MAINTAINING THE GUIDE BAR
1. Rotate the guide bar frequently, at regular intervals (for example,
after every 5 hours of operation), to ensure even wear on the top
and bottom of the guide bar. Refer to Removing and Installing
the Guide Bar and Saw Chain.
2. Clean the guide bar groove and oil passages whenever the saw
chain is removed, when the unit has been used heavily or when
the saw chain appears dirty. Use a screwdriver, putty knife, wire
brush or similar instrument to remove debris from the guide bar
groove (Fig. 38). Use a small, soft wire to remove any debris
from the chain oil discharge hole (Fig. 39).
NOTE: If the oil passages are clear, the saw chain will give off a
spray of oil shortly after it begins to rotate during operation.
3. Frequently check the guide bar for damage (Fig. 40). Feathering
and burring of the guide bar rails (the ridges on either side of the
bar groove) is a normal process of guide bar wear. Such faults
should be smoothed with a file as soon as they occur (Fig. 40). A
guide bar with the following faults should be replaced:
• Wear inside the guide bar rails that permits the chain to lay
sideways
• Bent guide bar
• Cracked or broken rails
• Spread rails
Refer to Replacing the Guide Bar and Saw Chain.
Lubricating the Guide Bar Sprocket Tip
The guide bar sprocket tip was lubricated at the factory, but
requires regular lubrication. Failure to lubricate the guide bar
sprocket tip will result in poor performance, damage to the unit and
will VOID the warranty.
NOTE: This procedure can be performed while the guide bar and
saw chain are still assembled on the unit.
1. Clean the guide bar sprocket tip thoroughly with a damp cloth
(Fig. 41).
2. Use a guide bar tip lube gun (not included) to inject grease into
the lubrication hole (Fig. 41). Inject grease until it appears on the
outer edge of the guide bar sprocket tip.
3. Rotate the saw chain by hand. Always wear heavy-duty
protective gloves. Make sure the chain brake is disengaged.
4. Repeat the lubrication process until the entire guide bar
sprocket tip is lubricated.
Restore original rounded shape
Guide Bar Groove
Flat File
Bur
24
Fig. 37
Oil Passages
Fig. 38
Chain Oil
Discharge Hole
Fig. 39
Uneven Wear Spread Rails
Fig. 40