Instruction Manual

MS 271, MS 271 C, MS 291, MS 291 C
English
33
Releasing the chain brake
N Pull the hand guard back toward the
front handle.
NOTICE
Always disengage chain brake before
accelerating engine and before starting
cutting work. The only exception to this
rule is when you check operation of the
chain brake.
High revs with the chain brake engaged
(chain locked) will quickly damage the
powerhead and chain drive (clutch,
chain brake).
The chain brake is designed to be
activated also by the inertia of the front
hand guard
if the forces are sufficiently high. The
hand guard is accelerated toward the
bar nose - even if your left hand is not
behind the hand guard, e.g. during a
felling cut. The chain brake will operate
only if it has been properly maintained
and the hand guard has not been
modified in any way.
Check operation of chain brake
Before starting work: Run engine at idle
speed, engage the chain brake (push
hand guard toward bar nose).
Accelerate up to full throttle for no more
than 3 seconds – the chain must not
rotate. The hand guard must be free
from dirt and move freely.
Chain brake maintenance
The chain brake is subject to normal
wear. It is necessary to have it serviced
and maintained regularly by trained
personnel, such as your STIHL servicing
dealer, at the following intervals:
Pre-heat carburetor
N Remove the shroud – see "Shroud"
At temperatures below +50 °F (+10 °C)
N Using the combination wrench or a
screwdriver, pry the shutter out of
the s (summer operation) position
N Place the slide with the opening in
the direction of the chain saw
(winter operation) – arrow points
toward symbol r – shutter must
audibly snap into place
In the winter operation position, the tip of
the arrow (1) is visible.
143BA012 KN
Full-time usage: every 3
months
Part-time usage: every 6
months
Occasional usage: every 12
months
Winter Operation
5902BA002 KN
5902BA003 KN
1