Maintenance - Makita BUC121 Instruction Manual

Pruning trees
Fig.12
Fig.13
CAUTION:
Keep all parts of the body away from the saw chain
•
when the motor is operating.
Hold the chain saw firmly with both hands when
•
the motor is running.
Do not overreach. Keep proper footing and
•
balance at all times.
Bring the tip guide/lower guide into contact with the
branch to be cut before switching on. Cutting without
bringing the tip guide/lower guide into contact with the
branch may cause the guide bar to wobble, resulting in
injury to operator.
When cutting thick branches, first make a shallow
undercut and then make the finish cut from the top.
Fig.14
If you try to cut off thick branches from the bottom, the
branch may close in and pinch the saw chain in the cut.
If you try to cut off thick branches from the top without a
shallow undercut, the branch may splinter.
Fig.15
If you cannot cut the timber right through with a single
stroke:
Apply light pressure to the handle and continue sawing
and draw the chain saw back a little; then apply the
spike a little lower and finish the cut by raising the
handle.
Fig.16
Carrying tool
Fig.17
Always remove the battery cartridge from the tool and
overlap the guide bar with the scabbard before carrying
the tool. Also cover the battery cartridge with the battery
cover.

MAINTENANCE

CAUTION:
Always be sure that the tool is switched off and the
•
battery cartridge is removed before attempting to
perform inspection or maintenance.
Always wear gloves
•
inspection or maintenance.
Sharpening the saw chain
CAUTION:
Always remove the battery cartridge and wear
•
safety gloves when performing work on the saw
chain.
Fig.18
when performing any
Sharpen the saw chain when:
− Mealy sawdust is produced when damp wood is
cut;
− The chain penetrates the wood with difficulty, even
when heavy pressure is applied;
− The cutting edge is obviously damaged;
− The saw pulls to the left or right in the wood. The
reason for this behaviour is uneven sharpening of
the saw chain, or damage to one side only.
Sharpen the saw chain frequently, but remove only a
little material each time.
Two or three strokes with a file are usually sufficient for
routine resharpening. When the saw chain has been
resharpened several times, have it sharpened in a
MAKITA specialist repair shop.
File and file guiding
− Use a special round file (optional accessory) for
saw chains, with a diameter of 4 mm, to sharpen
the chain. Normal round files are not suitable.
Fig.19
− The file should only engage the material on the
forward stroke. Lift the file off the material on the
return stroke.
− Sharpen the shortest cutter first. The length of this
cutter is then the gauge dimension for all other
cutters on the saw chain.
− Guide the file as shown in the figure.
− The file can be guided more easily if a file holder
(accessory) is employed. The file holder has
markings for the correct sharpening angle of 30 °
(align the markings parallel to the saw chain) and
limits the depth of penetration (to 4/5 of the file
diameter).
Guide the file as shown in the figure.
− After sharpening the chain, check the height of the
depth gauge using the chain gauge tool (optional
accessory).
Fig.20
− Remove any projecting material, however small,
with a special flat file (optional accessory).
− Round off the front of the depth gauge again.
− Wash away dust and particles from saw chain after
adjusting the height of depth gauge.
Cleaning guide bar
Fig.21
Chips and sawdust will build up in the guide bar groove,
clogging it and impairing oil flow. Always clean out the
chips and sawdust when sharpening or replacing the
saw chain.
Cleaning the oil filter at the oil discharge hole
Small dust or particles may be built up in the oil filter at
the oil discharge hole during operation.
Small dust or particles built up in the oil filter may impair
the oil discharge flow and cause an insufficient
lubrication on the whole saw chain.
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