Yamaha YZF-R125 Service Manual: 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 thermometer's indicated temperature.

Checking the thermostat


A. Fully closed

B. Fully open

NOTE:

If the accuracy of the thermostat is in doubt, replace it. A faulty thermostat could cause serious overheating or overcooling.

2. Check:

  • Thermostat cover Cracks/damage Replace.

3. Check:

  • Radiator inlet hose Cracks/damage  Replace.

    Thermostat
    ...

    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 ...

    Other materials:

    Removing the primary drive gear and balancer gears
    1. Loosen: Primary drive gear nut "1" NOTE: Place the aluminum plate "a" between the balancer drive gear "2" and the balancer driven gear "3", and then loosen the primary drive gear nut. 2. Straighten the lock washer tab. 3. Loosen: Balancer driven gear nut "1" NOTE: Place ...

    Checking the rear wheel
    1. Check: Rear wheel axle Rear wheel Wheel bearings Oil seals Refer to "CHECKING THE FRONT WHEEL" on page 4-8. 2. Check: Tire Rear wheel Damage/wear → Replace. Refer to "CHECKING THE TIRES" on page 3-23 and "CHECKING THE WHEELS" on page 3-25. 3. Measure: Radi ...

    Removing the rear wheel (disc)
    1. Stand the vehicle on a level surface. WARNINGSecurely support the vehicle so that there is no danger of it falling over. 2. Elevate: Rear wheel NOTE: Place the vehicle on a suitable stand so that the rear wheel is elevated. 3. Remove: Rear brake caliper NOTE: ...

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