3. Use a depth gauge tool (not included) to measure the depth
gauge clearance (Fig. 42) of each cutter. The depth gauge
clearance must be maintained at 1/32 inch (0.6 mm). The depth
gauge clearance determines the depth at which the cutter enters
the wood during operation and the size of the wood chips
produced. Too much clearance increases the chance of
kickback. Too little clearance decreases the size of the wood
chips, thus deceasing the ability to cut.
• Use a 0.025 inch (0.635 mm) depth gauge jointer and a flat file
(tools not included) to lower the depth gauge to the correct
clearance (Fig. 42).
• After lowering the depth gauge, use the flat file to restore the
original rounded shape to the depth gauge (Fig. 43). Take care
not to damage the cutting edges or nearby links.
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. 44). Use a small, soft wire to remove any debris
from the chain oil discharge hole (Fig. 45).
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. 46). 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. 46). 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.
REPLACING THE GUIDE BAR AND SAW CHAIN
WARNING:
Always use a low-kickback saw chain,
which significantly reduces the danger of kickback. Low-
kickback saw chain does not completely eliminate
kickback. A low-kickback or "safety chain," should never
be regarded as total protection against injury.
When replacing the guide bar and saw chain, only use the
replacement parts specified by the manufacturer or their
equivalents. Refer to Replacement Parts. Use of any unauthorized
parts or accessories could lead to serious injury to the operator or
damage to the unit and will VOID the warranty.
Always use a replacement saw chain designated as "low-kickback"
or a saw chain that meets the low-kickback performance
requirements. A standard saw chain (a chain that does not have the
kickback-reducing guard links) should only be used by an
experienced professional chain saw operator.
Restore original rounded shape
Guide Bar Groove
Flat File
Bur
27
Fig. 43
Oil Passage
Fig. 44
Chain Oil
Discharge Hole
Fig. 45
Uneven Wear
Spread Rails
Fig. 46