Yamaha YZF-R125 Service Manual: 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.
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.
...
Checking the ignition coil
1. Check:
Primary coil resistance
Out of specification Replace.
a. Disconnect the ignition coil connectors from
the ignition coil terminals.
b. Connect the pocket tester ( × 1)
to ...
Other materials:
Checking the radiator
1. Check:
Radiator fins
obstruction clean.
Apply compressed air to the rear of the radiator.
Damage repair or replace.
NOTE:
Straighten any flattened fins with a thin, flat-head
screwdriver.
2. Check:
Radiator hoses
Cracks/damage Replace.
3. Measure:
Radiator cap ...
Handlebar switches
Left
Left
1. Pass switch "PASS"
2. Dimmer switch "/"
3. Turn signal switch "/"
4. Horn switch""
Right
Right
Engine stop switch "/"
Start switch""
Pass switch "PASS"
Press this switch to flash the headlight.
Dimmer switch "/"
Set this switch to""
for the high
beam an ...
Installing the drive chain
1. Lubricate:
Drive chain
Master link
2. Install:
Drive sprocket
Drive sprocket retainer bolts
3. Install:
Master link
O-rings
Master link plate
Master link clip "1"
CAUTION:
The closed end of the master link clip must
face in the direction of drive ch ...