NOTICE
Do not remove the bearings for inspection. Removal may damage them.

The rollers and ball in a bearing normally wear very little, and wear is difficult to measure. Instead of measuring, visually inspect the bearing for abrasion, discoloration, or other damage.
If the needle bearing, and sleeve [B] show any sings of abnormal wear, discoloration, or damage, replace them as a set.
If bearing play, roughness, or binding is found, replace the bearing.
If the seal is torn or is leaking, replace the bearing.

Swingarm Bearing Lubrication
NOTE
Since the bearing are packed with grease and sealed, lubrication is not required.
Swingarm Bearing InstallationTransmission Shaft Disassembly
Remove the transmission shafts (see Transmission Shaft
Removal).
Remove the circlips, and then disassemble the transmission
shafts.
Special Tool - Outside Circlip Pliers: 57001-144
The 5th gear [A] on the output shaft has three steel balls
assembled into it for the positive neutral fin ...
Liquid Gasket, Non-permanent Locking Agent
For applications that require Liquid Gasket or a
Non-permanent Locking Agent, clean the surfaces so
that no oil residue remains before applying liquid gasket or
non-permanent locking agent. Do not apply them excessively.
Excessive application can clog oil passages and
cause serious damage.
...
Exhaust Device
This motorcycle is equipped with a
exhaust device system. This system
controls the valve in the exhaust pipe
and produces stable engine power at
low and middle engine speed. This exhaust
device is controlled by the ECU,
and adjustment or maintenance should
be done only by a competent mechanic ...