Yamaha YZF-R125 Service Manual: 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 opening pressure
Below the specified pressure
Replace the radiator cap.
a. Install the radiator cap tester "1" and radiator
cap tester adapter "2" to the radiator cap "3".
b. Apply the specified pressure for ten seconds and make sure there is no drop in pressure.
4. Check:
- Radiator fan
Damage
Replace.
Malfunction
Check and repair.Refer to "COOLING SYSTEM" on page 8-25.
Radiator
...
Installing the radiator
1. Fill:
Cooling system
(with the specified amount of the recommended
coolant)
Refer to "CHANGING THE COOLANT" on
page 3-15.
2. Check:
Cooling system
Leaks Repair or replace any
...
Other materials:
Installing the camshaft and rocker arms
1. Lubricate:
Rocker arms
Rocker arm shafts
2. Lubricate:
Camshaft
3. Install:
Camshaft "1"
NOTE:
Make sure that the camshaft projections "a" and
hole "b" are positioned as shown in the illustration.
4. Install:
Rocker arms
Rocker arm shafts "1"
NOTE:
Make ...
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
To check the drive chain slack
Place the motorcycle on the sidestand.
TIP
When checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.
Shift the transmission in ...
Removing the fuel tank
1. Extract the fuel in the fuel tank through the
fuel tank filler hole with a pump.
2. Remove:
Fuel hose connector cover "1"
3. Disconnect:
Fuel hose "2"
CAUTION:
Be sure to disconnect the fuel hose by
hand. Do not forcefully disconnect the
hose with tools.
A ...