10 Checking the Saw
10.1 Checking the Chain Sprocket
► Shut off the engine.
► Disengage the chain brake.
► Remove the chain sprocket cover.
► Remove the bar and chain.
► Use a STIHL gauge to check the wear marks
on the sprocket.
► If wear marks are deeper than a = 0.5 mm: Do
not use your chainsaw and contact your
STIHL servicing dealer for assistance.
The chain sprocket must be replaced.
10.2 Checking the Guide Bar
► Shut off the engine and engage the chain
brake.
► Remove the depth limiter.
► Remove the chain and guide bar.
► Measure depth of bar groove with scale on
STIHL filing gauge.
► Install a new guide bar if one of the following
points applies:
–
Guide bar is damaged.
–
Measured bar groove depth is less than
specified minimum depth, 19.3.
–
Bar groove is pinched or splayed.
► If you have any queries: Contact your STIHL
servicing dealer for assistance.
10.3 Checking the Saw Chain
► Shut off the engine and engage the chain
brake.
► Remove the depth limiter.
► Use a STIHL filing gauge (2) to check the
height of the depth gauges (1). The STIHL fil‐
ing gauge must match the chain pitch.
► If a depth gauge (1) projects from the filing
gauge (2): Use a STIHL USG to lower the
depth gauge (1), 16.3.
► Make sure the service marks (3, 4 and 6) on
the cutters and tie straps are visible.
► Check that the cutting edges (5) on the cutters
are in good condition.
► If one of the service marks on a cutter or tie
strap strip is no longer visible or a cutting edge
is missing: Do not use your saw chain and
contact your STIHL servicing dealer for assis‐
tance.
► Use a STIHL filing gauge to check that a filing
angle of 30° has been maintained on all cut‐
ters. The STIHL filing gauge must match the
chain pitch.
► If a filing angle of 30° has not been main‐
tained: Resharpen the saw chain.
► If you have any queries: Contact your STIHL
servicing dealer for assistance.
10.4 Testing the Chain Brake
► Shut off the engine and engage the chain
brake.
► Adjust the depth limiter so that a large portion
of the guide bar is visible.
English 10 Checking the Saw
16 0458-787-0121-B. VA0.M20.