42
7.7 FUSE REPLACEMENT
Lift the front bonnet. Unscrew the sleeve, take out the fuse and insert the new one having the same value
as the original fuse had, i.e. 20 A. If it is not possible to start the engine even after the fuse replacement,
contact the authorized service.
7.8 MACHINE JACKING UP
If You want to jack up the mowing machine, use a jack and supports. At the jacking up proceed as
follows:
• Place the jack under the gearbox and jack up the machine front part.
• Put two supports under both ends of axle inside the front wheels side.
• Jack up the machine front part and put two supports under ends of both king pins.
7.9 REPLACEMENT OF MOWING MECHANISM KNIVES
The mowing knives must be sharp, statically balanced and straight. These conditions are important for the evenness of height of
mowing and quality of cut.
Dull blades worsen the quality of mulching.
CAUTION !!!
At the moment the knives hit a solid obstacle, stop the engine immediately and check the knives! The shear pins may be
damaged or cut. Replace the cut pins with new ones provided in the machine equipment. Also check if the fi xing screws of
knives are tightened with the tightening torque specifi ed.
Replace the knives in the following way:
• Lift the mowing mechanism to the transport position.
• Unscrew both knives, clean them and carry out their sharpening. Check the static balance of knives (see the fi gure above).
• At reassembly see to it that the bendings of the blades are pointing upwards into the housing of the mowing mechanism. Do
not confuse the left knife with the right one. The right knife is provided with the screw having left-hand thread.
• Check the condition of the shear pins which serve as the protection of mowing mechanism against a damage. If the shear pins
are damaged replace them immediately.
• Tighten the fi xing screws of knives thoroughly with the specifi ed tightening torque of 30±3 Nm.
The screw is tightened
correctly once the tangential spring under the screw just reaches a fl at position, it must not be tightened any further than this
point - danger of damage to the cogged belt by moving blades!
7.9.1 SHARPENING
OF
KNIVES
The knife may be sharpened with a fi le or a grinder. Do not carry out the sharpening directly on the mowing mechanism.
Pay great attention to the alignment and balancing of knives. The vibrations generated by the unaligned and unbalanced knives
can cause a serious damage to the engine or mowing mechanism.
When balancing, insert a screwdriver into the centring hole and set
the knife into the horizontal position (see the fi gure 7.9 above). If
the knife remains in this position, it is balanced. If one of the knife
ends is overbalancing, carry out the grinding of this side until the
knife is balanced.
The allowable static unbalance may be 2g maximally.
7.10 STEERING
UNIT
MAINTENANCE
Check the play in the steering regularly. When an excessive backlash
is ascertained, take it up. At the backlash taking up, fi rst, straighten
the wheels into the direct direction. Loosen the nut
1
and take up the
backlash to the minimum by turning the adjusting screw
2
at the end
of wire rope. Then, retighten the nut
1
fi rmly. Carry out the same
adjustment at the other end of the chain. See to it that the wire ropes
on both ends of the chain are tightened equally.
