Yamaha YZF-R125 Service Manual: Checking the bulbs and bulb sockets
NOTE:
Do not check any of the lights that use LEDs.
Check each bulb and bulb socket for damage or wear, proper connections, and also for continuity between the terminals.
Damage/wear
Repair or replace
the bulb,
bulb socket or both.
Improperly connected 
Properly
connect.
No continuity 
Repair or replace the
bulb, bulb
socket or both.
Checking the switches
1. Clutch switch
2. Main switch
3. Front brake light switch
4. Sidestand switch
5. Rear brake light switch
6. Neutral switch
7. Turn signal switch
8. Horn switch
9. Dimmer switch
10.Pass ...
Types of bulbs
The bulbs used on this vehicle are shown in the
illustration.
Bulbs "a" and "b" are used for the headlights
and usually use a bulb holder that must be detached
before removing the bulb. The m ...
Other materials:
Removing the rear brake master cylinder
NOTE:
Before removing the rear brake master cylinder,
drain the brake fluid from the entire brake system.
1. Disconnect:
Rear brake light switch coupler
2. Loosen:
Rear brake light switch "1"
3. Remove:
Rear brake master cylinder bolts
Rear brake master cylinder
4. Remove:
...
Special tools
The following special tools are necessary for complete and accurate tune-up
and assembly. Use only
the appropriate special tools as this will help prevent damage caused by the use
of inappropriate tools
or improvised techniques. Special tools, part numbers or both may differ
depending on the ...
Unstable handling
Handlebars
- Bent or improperly installed right handlebar
- Bent or improperly installed left handlebar
1. Steering head components
- Improperly installed upper bracket
- Improperly installed lower bracket
(improperly tightened ring nut)
- Bent steering stem
- Damaged ball bearing or bearing ...