Yamaha YZF-R125 Service Manual: Installing the water pump
1. Install:
- Water pump assembly "1"
- O-rings "2"
NOTE:
- Align the projection "a" on the impeller shaft with the slit "b" on the camshaft sprocket bolt.
- Lubricate the O-rings with a thin coat of lithiumsoap- based grease.
2. Fill:
- Cooling system (with the specified amount of the recommended coolant)
Refer to "CHANGING THE COOLANT" on page 3-15.
3. Check:
Cooling system
Leaks 
Repair or replace the faulty
part.
4. Measure:
Radiator cap opening pressure
Below the specified pressure
Replace the
radiator cap.
Refer to "CHECKING THE RADIATOR" on page 6-3.
Assembling the water pump
1. Install:
Water pump seal "1"
(into the water pump housing "2")
CAUTION:Never lubricate the water pump seal
surface
with oil or grease.
NOTE:
Install the water pump ...
Fuel system
...
Other materials:
Installing the generator
1. Install:
Woodruff key
Generator rotor
Washer
Generator rotor nut
NOTE:
Clean the tapered portion of the crankshaft and
the generator rotor hub.
When installing the generator rotor, make sure
the woodruff key is properly sealed in the keyway
of the crankshaft.
2. Tighte ...
Troubleshooting
Although Yamaha motorcycles receive
a thorough inspection before shipment
from the factory, trouble may occur during
operation. Any problem in the fuel,
compression, or ignition systems, for
example, can cause poor starting and
loss of power.
The following troubleshooting charts
repre ...
Cast wheels
To maximize the performance, durability,
and safe operation of your vehicle,
note the following points regarding the
specified wheels.
The wheel rims should be checked
for cracks, bends or warpage before
each ride. If any damage is
found, have a Yamaha dealer replace
the wheel. ...