Yamaha YZF-R125 Service Manual: Circuit diagram
4. Main fuse
5. Main switch
6. Radiator fan motor fuse
9. Battery
22.Coolant temperature sensor
32.Radiator fan motor relay
33.Radiator fan motor
59.Coolant temperature warning light
64.Ignition fuse
66.Signaling system fuse
Cooling system
...
Troubleshooting
NOTE:
Before troubleshooting, remove the following part(s):
1. Rider seat
2. Fuel tank
3. Right upper side cowling
4. Passenger seat
...
Other materials:
Types of bulbs
The bulbs used on this vehicle are shown in the
illustration.
Bulbs "a" and "b" are used for the headlights
and usually use a bulb holder that must be detached
before removing the bulb. The majority
of these types of bulbs can be removed from
their respective socket by turning them coun ...
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 the ignition
coil as shown.
Positive tester probe
red/white "1"
Negative tester probe
orange ...
Checking the camshaft sprocket and timing chain guide
1. Check:
Camshaft sprocket
More than 1/4 tooth wear "a" Replace
the
camshaft sprocket, timing chain and crankshaft
as a set.
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
2. Check:
Timing chain guide (exhaust side)
Damage/wear Replace.
...