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:
Faulty clutch
Clutch slips
1. Clutch
Improperly assembled clutch
Improperly adjusted clutch cable
Loose or fatigued clutch spring
Worn friction plate
Worn clutch plate
2. Engine oil
Incorrect oil level
Incorrect oil viscosity (low)
Deteriorated oil
Clutch drags
1. Clutch
Unevenly t ...
Removing the primary drive gear and balancer gears
1. Loosen:
Primary drive gear nut "1"
NOTE:
Place the aluminum plate "a" between the balancer
drive gear "2" and the balancer driven
gear "3", and then loosen the primary drive gear
nut.
2. Straighten the lock washer tab.
3. Loosen:
Balancer driven gear nut "1"
NOTE:
Place ...
Checking the starter motor operation
1. Check:
Starter motor operation
Does not operate → Perform the electric
starting system troubleshooting, starting with
step 4.
Refer to "TROUBLESHOOTING" on page
8-9.
a. Connect the positive battery terminal "1" and
starter motor lead "2" with a jumper lead "3".
W ...