Yamaha YBR 125 Service Manual page 214

2.Voltage
Connect min. Multitester(DC20V) to branchconn-
nector of fuel gange.(at the side of bundle conductor)
Check if the brown wire voltage at the fuel gauge
binding post (at the side of bundle conductor)gets
to 12V.
3.Fuel gauge
Connect fuel level sensor to circuit joint
Move the float up and down .
Turn the main switch to "ON".
Move the float to Max. upper postion or
max. Lower position to check the fuel gallge
needle's action
Position of float bowl Needle of fuel gauge
Upper float bowl
Lower float bowl
The loop connection of signal system is normal
Meet normal value
Showing F
Showing E
Normal
Signal system
Out of normal value
Check all socket connectors of singal system
Remark
Firm the float bowl on the 1 or 2 position respectively
for over 3 minutes to confirm the needle of fuel gauge.
Poor function
7-38
ELEC
Replace petrol gauge