If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterCrankshaft Installation
NOTE
If the crankshaft is replaced with a new one, refer to
the Connecting Rod Big End Bearing/Crankshaft Main
Bearing Insert Selection in the Specifications.
NOTICE
If the crankshaft, bearing inserts, or crankcase
halves are replaced with new ones, select the bearing
inserts and check cleara ...
Specifications
Connecting Rod Big End Bearing Insert Selection
Crankshaft Main Bearing Insert Selection
*: The bearing inserts for Nos. 2 and 4 journals have an oil groove,
respectively. ...
Hub Bearing Installation
Before installing the hub bearings, blow any dirt or foreign
particles out of the hub with compressed air to prevent
contamination of the bearings.
Replace the bearings with new ones.
Install the bearings by using the bearing driver set which
does not contact the bearing inner race.
...