User Instructions

ENSK
25
TRHUSRHRCSLVLTROELBGETAZKK
0478 111 9841 B - EN
12.4 Checking blade wear
Maintenance interval:
Before each use
● Tilt the mower upwards into the
cleaning position. (Ö 12.3)
● Clean the mowing blade (1).
● Place a ruler (1) against the front blade
edge and measure permissible
grinding A.
● Measure blade width B using a slide
calliper (2).
● Check blade thickness C at 5 points at
least using a slide calliper (2). In
particular, minimum thickness must
also be ensured in the area of the blade
wings.
Wear limits:
Permissible grinding A: < 15mm
Blade width B: > 39 mm
Blade thickness C: > 2 mm
The blade must be replaced,
– if it is damaged (notches, cracks),
– if the measured values are achieved at
one or more points or are outside the
permissible limits.
If the multi-blade available as a special
accessory is installed on the lawn mower,
different wear limits apply (see instruction
manual for accessory).
12.5 Removing and installing the
mowing blade
Removing:
● Use a suitable wooden block (1) to
counterhold mowing blade (2).
● Unscrew the blade fastening screw (3).
Remove the mowing blade (2), blade
fastening screw (3) and retaining
washer (4).
Installation:
● Clean the blade contact surface and
blade bushing.
● Install the mowing blade (2) with the
curved wings pointing upwards
(towards the machine). The locating
lugs (5) on the blade bushing must be
located in the bores (6) of the mowing
blade.
● Use a suitable wooden block (1) to
counterhold mowing blade (2).
● Install the blade fastening screw (3)
with a new retaining washer (4) and
tighten.
Tightening torque: 60 - 65 Nm
12.6 Sharpening the mowing blade
STIHL recommends having the mowing
blade sharpened by a technician.
Operation of the machine is impaired in the
case of an incorrectly sharpened blade
(incorrect sharpening angle, imbalance,
etc.).
Sharpening instructions:
● Remove the mowing blade. (Ö 12.5).
● Cool the mowing blade when
sharpening, e.g. with water. The blade
must not be allowed to display blue
colouring, as this would reduce its
cutting quality.
● Sharpen the blade evenly to prevent
vibrations due to imbalance.
● Observe the sharpening angle of 30°.
● After sharpening, remove any
sharpening burr at the cutting edge
using fine sandpaper if necessary.
● Observe the wear limits. (Ö 12.4)
Risk of injury!
Blades are subjected to differing
degrees of wear depending on the
location and duration of use. If you
use the machine on sandy ground
or use it frequently under dry
conditions, the blade will be
subjected to greater loads and will
wear more quickly than the
average. A worn blade may break
off and cause serious injuries. The
instructions for blade maintenance
must therefore always be observed.
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Risk of injury!
The mowing blade (2) must only be
installed as shown. The tabs (7)
must face downwards and the
curved wings must point upwards.
Observe the specified torque when
tightening the blade fastening
screw, as the secure attachment of
the cutting tool depends on this.
Additionally secure the blade
fastening screw (3) with
Loctite 243.
Replace the spring washer (4) each
time the blade is installed and the
blade fastening screw (3) each time
the blade is replaced.
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