Yamaha YZF-R125 Service Manual: 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 probe gray "1"
- Negative tester probe gray/black "2"
b. Set the main switch to "ON".
c. Elevate the front wheel and slowly rotate it.
d. Measure the voltage of gray and gray/black.
With each full rotation of the front wheel, the voltage reading should cycle from 0 V to 5.0 V to 0 V to 5.0 V.
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 c ...
Checking the radiator fan motor
1. Check:
Radiator fan motor
Faulty/rough movement → Replace.
a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
Posi ...
Other materials:
Checking the spark plug cap
1. Check:
Spark plug cap resistance
Out of specification Replace.
a. Remove the spark plug cap from the spark
plug lead.
b. Connect the pocket tester ( × 1k)
to the
spark plug cap as shown.
c. Measure the spark plug cap resistance. ...
Installing the rear brake master cylinder
1. Install:
Copper washers "1"
Brake hose "2"
Rear brake light switch "3"
WARNINGProper brake hose routing is essential to
insure
safe vehicle operation. Refer to "CABLE
ROUTING" on page 2-33.
CAUTION:When installing the brake hose onto the
brake master ...
Periodic maintenance and adjustment
Periodic inspection, adjustment, and lubrication
will keep your vehicle in the
safest and most efficient condition possible.
Safety is an obligation of the vehicle
owner/operator. The most important
points of vehicle inspection, adjustment,
and lubrication are explained on
the followin ...