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:

    Checking the clutch housing
    1. Check: Clutch housing dogs "1" Damage/pitting/wear  Deburr the clutch housing dogs or replace the clutch housing. NOTE: Pitting on the clutch housing dogs will cause erratic clutch operation. 2. Check: Bearing Damage/wear Replace the bearing and clutch housin ...

    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. Place a thermometer "4" in the water. d. While stirring the water, observe the thermostat and th ...

    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 ...

    2026 Copyright www.yam-r125.net |