Replacing Carbon Brushes - Makita BUC121 Instruction Manual

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.
When a poor chain oil delivery occurs at the top of
guide bar, clean the filter as follows.
Remove the battery cartridge from the tool.
Remove the sprocket cover and saw chain from the tool.
(Refer to the section titled " Installing or removing saw
chain ".)
Fig.22
Remove the push nut using a slotted bit screwdriver with
a slender shaft or the like.
Fig.23
Take the filter out of the chain saw and remove small
dust or particles from it. When the filter is too dirty,
replace it with a new one.
Insert the battery cartridge into the tool.
Fig.24
Pull the switch trigger to flow built-up dust or particles off
the oil discharge hole by discharging chain oil.
Remove the battery cartridge from the tool.
Fig.25
Insert the cleaned oil filter into the oil discharge hole.
When the filter is too dirty, replace it with a new one.
Fig.26
Insert the push nut with its correct side facing up as
shown in the figure into the oil discharge hole to secure
the filter. When the filter cannot be secured with a
disfigured push nut, replace the push nut with a new
one.
Reinstall the sprocket cover and saw chain on the tool.
Replacing the sprocket
Before fitting a new saw chain, check the condition of the
sprocket.
Fig.27
CAUTION:
A worn sprocket will damage a new saw chain.
•
Have the sprocket replaced in this case. The
sprocket need to be installed so that it always
faces as shown in the figure.
Fig.28
Always fit a new locking ring when replacing the
sprocket.

Replacing carbon brushes

Fig.29
Remove and check the carbon brushes regularly.
Replace when they wear down to the limit mark. Keep
the carbon brushes clean and free to slip in the holders.
Both carbon brushes should be replaced at the same
time. Use only identical carbon brushes.
Use a screwdriver to remove the brush holder caps.
Take out the worn carbon brushes, insert the new ones
and secure the brush holder caps.
Fig.30
Storing tool
Clean the tool before storing. Remove any chips and
sawdust from the tool after removing the sprocket cover.
After cleaning the tool, run it under no load to lubricate
the saw chain and guide bar.
Cover the guide bar with the scabbard.
Remove oil from the oil tank to empty it and place the
chain saw with the tank cap facing upward.
To maintain product SAFETY and RELIABILITY, repairs,
any other maintenance or adjustment should be
performed by Makita Authorized Service Centers,
always using Makita replacement parts.
ACCESSORIES
CAUTION:
These accessories
•
recommended for use with your Makita tool
specified in this manual. The use of any other
accessories or attachments might present a risk of
injury to persons.
attachment for its stated purpose.
If you need any assistance for more details regarding
these accessories, ask your local Makita Service Center.
Various type of Makita genuine batteries and
•
chargers
Saw chain
•
Scabbard
•
Guide bar complete
•
File
•
12
or attachments
Only use accessory or
are