Masport AB107, Owner'S Manual, Page: 37 / 48

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6.3.6 MOWING DECK - SHARPENING AND REPLACING THE BLADES
► SHARPENING THE BLADES
The mowing blades must be sharp, statically balanced and straight. Blunt, incorrectly sharpened or damaged mowing blades
cause grass to be torn out of the ground, damage to lawns and mediocre collection of mowed grass in the grass catcher.
Do not repair a blade that is deformed or otherwise damaged, replace it immediately.
Whenever handling the mowing blades, always use heavy-duty work gloves.
Sharpening procedure:
6.3.6a
►
Locate the machine so that you have access under the mowing deck. You can either lift up the machine using
a cradle-type mower jack or transport it to a service workshop equipped with a suitable garage pit (
6.3.5).
►
Unscrew both blades and clean them.
►
First sharpen with a grinder and then with a file.
Do not sharpen directly on the mowing deck.
►
After sharpening the blades, do not install them yet, but check their balance, see procedure below.
►
Prior to reinstalling the blades, check the condition of the break pins which serve as protection of the mowing deck.
If the break pins are damaged, replace them immediately. Spare pins are supplied with the machine.
6.3.6b
►
After checking the balance and the brake pins, screw the blades back in position. During installation, ensure that the bend of the
blades points upwards into the mowing deck body. Do not interchange the left and right blades. The right blade has a bolt with
a left thread.
►
Carefully tighten the fastening bolts using a torque wrench using the prescribed tightening torque of 30
±
3 Nm . This torque is
achieved the moment when the tangential (convex) spring under the fastening bolt is fully compressed and from this point on the
bolt is not tightened.
► BALANCING THE BLADES
Pay increased attention to levelling and balancing the blades. The vibration of blades that are not levelled and balanced may
damage the engine or the mowing deck.
When balancing, insert the screwdriver into the centring hole and set the blade into
a horizontal position. If the blade remains in this position, it is balanced. If one of the ends
is weighs down, grind this side until it is balanced. When balancing by grinding, do not
shorten the length of the blade! The permitted static imbalance may not exceed 2g.
If you are not certain about the procedure, please contact an authorised service centre, where they will gladly provide advice.
► REPLACING BLADES
If due to frequent use the blades are damaged, they cannot be balanced or sharpened properly, it is necessary to replace them.
Proceed as follows:
►
Lift up the machine using a cradle-type mower jack or drive over a suitable garage pit ( 6.3.5) so that you have access to the
mowing deck.
►
Screw out both blades ( 6.3.6a).
►
Prior to installing new blades, check the condition of the brake pins which serve as protection of the mowing deck. If the break
pins are damaged, replace them immediately (
6.3.6b).
►
Check that the blades are balanced, see above.
►
Screw on the new blades. During installation, ensure that the bend of the blades points upwards into the mowing deck body. Do
not interchange the left and right blades. The right blade has a bolt with a left thread.
►
Carefully tighten the fastening bolts using a torque wrench using the prescribed tightening torque of 30
±
3 Nm . This torque is
achieved the moment when the tangential (convex) spring under the fastening bolt is fully compressed and from this point on the
bolt is not tightened.
When the blades impact a solid obstacle, immediately stop the engine and check the blades! The break pins may be
damaged or broken.
Whenever handling the mowing blades, always use heavy-duty work gloves.
Always only use blades recommended by the manufacturer or supplier of the riding mower. The use of blades and/or
fastening parts that are not recommended may result in improper mowing results, damage to the machine and in the
event that they come off during operation also injury to people.
6.3.7 MOWING DECK - INSPECTION AND BALANCING
The mowing deck is equipped with plastic covers which prevent hand access to moving parts and to the machine drive
parts of the machine.
The covers can be very quickly and easily removed using the quick coupling pins on the sides of the covers. Slide
a screwdriver into the pin groove and turn it anticlockwise. Then take the cover off the machine.
6.3.7a