Check the leads, couplers, and connectors for stains, rust, moisture, etc.
1. Disconnect:
2. Check:
Moisture → Dry with an air blower.
Rust/stains → Connect and disconnect several times.

3. Check:
Loose connection → Connect properly.
NOTE:
If the pin "1" on the terminal is flattened, bend it up.

4. Connect:
NOTE:
Make sure all connections are tight.
5. Check:

NOTE:
If there is no continuity, clean the terminals.
When checking the wire harness, perform steps (1) to (3).
As a quick remedy, use a contact revitalizer available at most part stores.

Circlips
Special toolsRemoving 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:
...
Identification numbers
Record the key identification number,
vehicle identification number and model
label information in the spaces provided
below for assistance when
ordering spare parts from a Yamaha
dealer or for reference in case the vehicle
is stolen.
KEY IDENTIFICATION NUMBER:
VEHICLE IDENTIFICATION ...
Removing the front brake caliper
NOTE:
Before disassembling the brake caliper, drain
the brake fluid from the entire brake system.
1. Remove:
Brake hose union bolt "1"
Copper washers "2"
Brake hose "3"
NOTE:
Put the end of the brake hose into a container
and pump out the brake fluid carefully.
...