11.6 Checking blade wear
Maintenance interval:
Before each use
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.
Checking procedure
Risk of injury!
Observe the safety instructions in
the "For your safety" section.
(
4.7)
● Place the machine in the cleaning
position. (
11.1)
● Clean mowing blade (1) and check for
notches and cracks.
● Use slide calliper (2) to measure the
blade thickness A at several points.
● Measure the blade width as illustrated
at the points B and C on the left and
right of the blade.
Wear limits:
The blade thickness A must be at least
2,5 mm at any point.
The blade width must be at least 80 mm at
point B and at least 55 mm at point C.
0478 111 9937 B - EN
Different wear limits apply if e.g. the
mulching blade available as a special
accessory is installed in the lawn mower
22
instead of the supplied mowing blade.
11.7 Removing and installing the
mowing blade
Risk of injury!
Always wear gloves.
Removing
● Place the machine in the cleaning
position. (
11.1)
● Hold mowing blade (1) and loosen
blade fastening screw (2).
● Remove blade fastening screw (2),
retaining washer (3) and mowing
blade (1).
Assembly
Avoid damage to the machine!
The mowing blade must be
replaced if notches or cracks are
detected or if a wear limit is
reached (
11.6).
● Clean the blade contact surface and
blade holder.
● Secure the blade fastening screw with
Loctite 243.
● Place mowing blade (1) on blade
holder (4) as illustrated.
● Position retaining washer (3) as
illustrated and tighten with blade
fastening screw (2) to 60 - 65 Nm.
Risk of injury!
The prescribed tightening torque
must be observed.
Retaining washer (3) must be
replaced each time the blade is
installed.
Blade fastening screw (2) must be
renewed each time the blade is
23
replaced.
11.8 Sharpening the mowing blade
If mowing results deteriorate over time,
this is usually the result of a blunt mowing
blade.
The following points must be noted when
resharpening:
● Remove the mowing blade. (
● 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 blades evenly to prevent
vibration due to imbalance.
● The cutting angle of 30° must be
observed.
● Observe the wear limits when
sharpening.
● Remove any sharpening burr.
11.9 Cable maintenance
The throttle cable must only be
maintained by trained personnel. STIHL
recommends STIHL specialist dealers.
11.7)
49