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 shift forks
    The following procedure applies to all of the shift forks. 1. Check: Shift fork cam follower "1" Shift fork pawl "2" Bends/damage/scoring/wear Replace the shift fork. 2. Check: Shift fork guide bar Roll the shift fork guide bar on a flat surface. Bends  Replace. ...

    Setting the diagnostic mode
    1. Set the main switch to "OFF" and the engine stop switch to " ". 2. Disconnect the self-diagnosis signal connector "1", and then connect the FI diagnostic tool "2" as shown. 3. Disconnect the fuel pump coupler. 4. While pressing the "MODE" button, set the main switch to "ON". NOTE: ...

    Checking the fid (fast idle solenoid)
    1. Disconnect: FID (fast idle solenoid) coupler 2. Check: FID (fast idle solenoid) resistance a. Disconnect the FID (fast idle solenoid) coupler from the FID. b. Connect the pocket tester ( × 10) to the terminals of the FID (fast idle solenoid). Positive tester probe ...

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