Owner's Manual

MS 251, MS 251 C
English
50
N Use a screwdriver to remove the E-
clip (1)
N Remove the washer (2)
N Remove rim sprocket (3) (if so
equipped), clutch drum (4) and
needle cage (6).
N Inspect transport profile for rim
sprocket on the clutch drum (4) – if
there are also heavy signs of wear,
also replace the clutch drum
N Remove clutch drum with integrated
spur chain sprocket (5) (if so
equipped) including needle cage (6)
from the crankshaft – for
powerheads with Quickstop Plus
chain brake system, depress
throttle trigger lockout beforehand
Install spur chain sprocket / rim sprocket
N Clean crankshaft stub and needle
cage and lubricate with STIHL
lubricant (special accessory)
N Slide needle cage onto the
crankshaft stub
N After refitting, turn the clutch drum
and/or spur chain sprocket approx.
1 full turn so that the carrier for the
oil pump drive engages
N Refit the rim sprocket – cavities
toward the outside
N Refit washer and E-clip on the
crankshaft
Sawing effortlessly with a properly
sharpened saw chain
A properly sharpened saw chain cuts
through wood effortlessly even with very
little pushing.
Never use a dull or damaged saw chain
– this leads to increased physical strain,
increased vibration load, unsatisfactory
cutting results and increased wear.
N Clean the saw chain
N Check the saw chain for cracks and
damaged rivets
N Replace damaged or worn chain
components and adapt these parts
to the remaining parts in terms of
shape and level of wear – rework
accordingly
Carbide-tipped (Duro) saw chains are
especially wear-resistant. For an optimal
sharpening result, STIHL recommends
STIHL servicing dealers.
WARNING
Compliance with the angles and
dimensions listed below is absolutely
necessary. An improperly sharpened
saw chain – especially depth gauges
that are too low – can lead to increased
kickback tendency of the chain saw –
risk of injury!
001BA122 KN
1
2
4
5
6
1
2
3
6
Maintaining and Sharpening
the Saw Chain