Yamaha YBR 125 Service Manual page 192

ELEC
Starting system
7.Clutch switch
Remove the branch-connector of clutch switch from
the bale of wire.
Check if the clutch switch is conducted between
"the black" and "the black "
R
Abnormal
If the clutch switch is failure,replace it
Normal
Poor connection,break
8.Wire joint
Refer to the loop wire of starting system
Correct or replace
7-16