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:
Checking the engine oil level
1. Stand the vehicle on a level surface.
NOTE:
Place the vehicle on a suitable stand.
Make sure the vehicle is upright.
2. Start the engine, warm it up for several minutes,
and then turn it off.
3. Check:
Engine oil level
The engine oil level should be between the
minimum level ...
Checking the oil pump
1. Check:
Oil pump drive gear
Oil pump driven gear
Oil pump housing
Oil pump housing cover
Cracks/damage/wear Replace the
defective
part(s).
2. Measure:
Inner-rotor-to-outer-rotor-tip clearance "a"
Outer-rotor-to-oil-pump-housing clearance
"b"
- Oil-pump-housing-to-inn ...
Fuel tank cap
Fuel tank cap
Fuel tank cap lock cover
Unlock.
To remove the fuel tank cap
Open the fuel tank cap lock cover.
Insert the key into the lock and turn
it 1/4 turn counterclockwise. The
lock will be released and the fuel
tank cap can be removed.
To install the fuel tank ca ...