Yamaha YZF-R125 Service Manual: Checking the fuel sender
1. Drain the fuel from the fuel tank.
2. Check:
Fuel sender resistance
Out of specification → Replace the fuel
sender.
a. Connect the pocket tester ( 
×
10) to the fuel
sender coupler as shown.
- Positive tester probe
sky blue "1" - Negative tester probe
orange/white "2"
A. Full fuel tank position
B. Empty fuel tank position
b. Measure the fuel sender resistance.
Checking the horn
1. Check:
Horn resistance
Out of specification Replace.
a. Disconnect the horn connectors from the
horn terminals.
b. Connect the pocket tester ( × 1) to the horn
terminals.
Positiv ...
Checking the speed sensor
1. Check:
Speed sensor output voltage
Out of specification → Replace.
a. Connect the pocket tester (DC 20 V) to the
speed sensor coupler (wire harness end) as
shown.
Positive tester pro ...
Other materials:
Checking the front fork
1. Stand the vehicle on a level surface.
WARNINGSecurely support the vehicle so that there
is
no danger of it falling over.
2. Check:
Inner tube
Damage/scratches Replace.
Oil seal
Oil leakage Replace.
3. Hold the vehicle upright and apply the front
brake.
4. Che ...
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/ ...
Checking the turn signal relay
1. Check:
Turn signal relay input voltage
Out of specification →The wiring circuit
from
the main switch to the turn signal relay coupler
is faulty and must be repaired.
a. Connect the pocket tester (DC 20 V) to the
turn signal relay terminal as shown.
- Positive tester probe
b ...