Yamaha YZF-R125 Service Manual: Checking the stator coil
1. Disconnect:
- Stator coil coupler (from the wire harness)
2. Check:
Stator coil resistance
Out of specification → Replace the
crankshaft
position sensor/stator assembly.
a. Connect the pocket tester ( 
×
1) to the stator
coil coupler as shown.
b. Measure the stator coil resistance.
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. Con ...
Checking the rectifier/regulator
1. Check:
Rectifier/regulator output voltage
Out of specification → Replace the
rectifier/
regulator.
a. Set the engine tachometer to the spark plug
lead.
b. Connect the pocket tester ...
Other materials:
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 ...
Disassembling the front wheel
1. Remove:
Oil seal
Wheel bearings
a. Clean the surface of the front wheel hub.
b. Remove the oil seal "1" with a flat-head
screwdriver.
NOTE:
To prevent damaging the wheel, place a rag "2"
between the screwdriver and the wheel surface.
c. Remove the wheel bearings "3" with a ge ...
Engine break-in
There is never a more important period
in the life of your engine than the period
between 0 and 1000 km (600 mi). For
this reason, you should read the following
material carefully.
Since the engine is brand new, do not
put an excessive load on it for the first
1000 km (600 mi). The vari ...