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 rocker arms and rocker arm shafts
    The following procedure applies to all of the rocker arms and rocker arm shafts. 1. Check: Rocker arm Damage/wear Replace. 2. Check: Rocker arm shaft Blue discoloration/excessive wear/pitting/ scratches  Replace or check the lubrication system. 3. Measure: Rocke ...

    Adjusting the throttle cable free play
    Throttle cable free play The throttle cable free play should measure 3.0-5.0 mm (0.12-0.20 in) at the throttle grip. Periodically check the throttle cable free play and, if necessary, adjust it as follows. TIP The engine idling speed must be correctly adjusted before checkin ...

    Checking the clutch plates
    The following procedure applies to all of the clutch plates. 1. Check: Clutch plate Damage Replace the clutch plates as a set. 2. Measure: Clutch plate warpage (with a surface plate and thickness gauge "1") Out of specification Replace the clutch plates as a set. ...

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