Yamaha YZF-R125 Service Manual: Installing the primary drive gear and balancer gears
1. Install:
- Balancer driven gear "1"
- Lock washer
- Balancer drive gear "2"
- Primary drive gear
- Washer "3"
- Balancer driven gear nut
- Primary drive gear nut
NOTE:
- Align the punch mark "a" in the balancer drive gear "2" with the punch mark "b" in the balancer driven gear "1".
- Be sure to install the washer so that its sharp edge "c" is facing the primary drive gear.
2. Tighten:
- Balancer driven gear nut "1"
- Primary drive gear nut "2"
NOTE:
- Place the aluminum plate "a" between the balancer drive gear "3" and the balancer driven gear "4", and then tighten the balancer driven gear nut.
- Place the aluminum plate "b" between the balancer drive gear "3" and the balancer driven gear "4", and then tighten the primary drive gear nut.
3. Bend the lock washer tab along a flat side of the nut.
Checking the balancer gears and primary drive gear
1. Check:
Balancer drive gear
Balancer driven gear
Cracks/damage/wear Replace.
2. Check:
Primary drive gear
Refer to "CHECKING THE PRIMARY DRIVE
GEAR" on page 5-43.
...
Crankcase
...
Other materials:
Checking the rear brake master cylinder
1. Check:
Brake master cylinder
Damage/scratches/wear Replace.
Brake fluid delivery passages
(brake master cylinder body)
Obstruction Blow out with
compressed air.
2. Check:
Brake master cylinder kit
Damage/scratches/wear Replace.
3. Check:
Brake fluid reservoir
Cracks/ ...
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
To check the drive chain slack
Place the motorcycle on the sidestand.
TIP
When checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.
Shift the transmission in ...
Coolant
The coolant level should be checked
before each ride. In addition, the coolant
must be changed at the intervals
specified in the periodic maintenance
and lubrication chart.
To check the coolant level
Place the vehicle on a level surface
and hold it in an upright position.
TIP
...