Yamaha YZF-R125 Service Manual: Installing the thermostat
1. Install:
- Thermostat
NOTE:
Install the thermostat with its breather hole "a"
facing up.
2. Install:
- Copper washer
- Coolant temperature sensor
| CAUTION: Use extreme care when handling the coolant temperature sensor. Replace any part that was dropped or subjected to a strong impact. |
3. Fill:
- Cooling system (with the specified amount of the recommended coolant) Refer to "CHANGING THE COOLANT" on page 3-15.
4. Check:
- Cooling system
Leaks
Repair or replace any
faulty part.
5. Measure:
- Radiator cap opening pressure
Below the specified pressure
Replace the radiator cap.Refer to "CHECKING THE RADIATOR" on page 6-3.
Checking the thermostat
1. Check:
Thermostat
Does not open at 80.5-83.5 C (176.9-182.3
F) Replace.
a. Suspend the thermostat "1" in a container "2"
filled with water.
b. Slowly heat the water "3".
c. ...
Water pump
...
Other materials:
Measuring the compression pressure
NOTE:
Insufficient compression pressure will result in a
loss of performance.
1. Measure:
Valve clearance
Out of specification →Adjust.
Refer to "ADJUSTING THE VALVE CLEARANCE"
on page 3-3.
2. Start the engine, warm it up for several minutes,
and then turn it off.
3. Remove:
...
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 amou ...
Checking the radiator fan motor
1. Check:
Radiator fan motor
Faulty/rough movement → Replace.
a. Disconnect the radiator fan motor coupler
from the wire harness.
b. Connect the battery (DC 12 V) as shown.
Positive tester probe →
blue "1"
Negative tester probe →
black "2"
c. Measure ...