Yamaha YZF-R125 Service Manual: Checking the diode
1. Check:
Diode
Out of specification 
Replace.
NOTE:
The pocket tester or the analog pocket tester
readings are shown in the following table.
a. Disconnect the diode from the wire harness.
b. Connect the pocket tester (
× 1)
to the diode
terminals as shown.
c. Check the diode for continuity.
d. Check the diode for no continuity.
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 poc ...
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 ...
Other materials:
Parking
When parking, stop the engine, and
then remove the key from the main
switch.
WARNING
Since the engine and exhaust
system can become very hot,
park in a place where pedestrians
or children are not likely to
touch them and be burned.
Do not park on a slope or on soft
ground, ...
Checking the piston pin
1. Check:
Piston pin
Blue discoloration/grooves
Replace the
piston pin and then check the lubrication system.
2. Measure:
Piston pin outside diameter "a"
Out of specification Replace
the piston pin.
3. Measure:
Piston pin bore diameter "b"
Out of specifica ...
Troubleshooting
The starter motor fails to turn.
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Left lower side cowling
4. Left upper side cowling
...