Stihl MS 391 - Page 57

MS 311, MS 391
English
35
When the specified files and/or
sharpening tools and the proper setting
are used, the specified values for angles
A and B will be attained automatically.
The angles must be identical for all
cutters in the saw chain. Varying angles:
Rough, uneven running of the saw
chain, increased wear – even to the
point of saw chain breakage.
Because these requirements can be met
only after sufficient, constant practice:
N Use a file holder
Always use a file holder (special
accessory, see table "Sharpening tools")
when sharpening saw chains by hand.
File holders have markings for the
sharpening angle.
To check the angles
STIHL filing gauge (special accessory,
see table "Sharpening tools") – a
universal tool for checking sharpening
and side plate angles, depth gauge
setting, and tooth length, as well as
cleaning grooves and oil inlet holes.
Proper sharpening
N Select sharpening tools in
accordance with chain pitch
N Clamp guide bar if necessary
N Block saw chain – push the hand
guard forward
N To advance the saw chain, pull the
hand guard toward the handlebar:
The chain brake is disengaged.
With the Quickstop Super chain
brake system, additionally press the
throttle trigger lockout
N Sharpen frequently, removing little
material – two or three strokes of the
file are usually sufficient for simple
resharpening
N Guide the file: horizontally (at a
right angle to the side surface of the
guide bar) in accordance with the
specified angle – according to the
markings on the file holder – rest the
file holder on the tooth head and the
depth gauge
N File only from the inside outward
N The file only sharpens on the
forward stroke – lift the file on the
backstroke
N Do not file tie straps and drive links
N Rotate the file a little periodically in
order to avoid uneven wear
N To remove file burr, use a piece of
hardwood
N Check angle with file gauge
All cutters must be equally long.
Chain Type Angle (°)
AB
Rapid Micro (RM) 30 75
Rapid Super (RS) 30 60
Picco Micro (PM) 30 75
Rapid Micro X (RMX, rip-
ping chain)
10 75
Picco Micro X (PMX, rip-
ping chain)
10 75
Tooth shapes
Micro = semi-chisel tooth
Super = chisel tooth
689BA025 KN
001BA203 KN
689BA018 KN
90°
689BA043 KN