Yamaha YZF-R125 Service Manual: 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"

Checking the radiator fan motor


c. Measure the radiator fan motor movement.

    Checking the speed sensor
    1. Check: Speed sensor output voltage Out of specification → Replace. a. Connect the pocket tester (DC 20 V) to the speed sensor coupler (wire harness end) as shown. Positive tester pro ...

    Checking the coolant temperature sensor
    1. Remove: Coolant temperature sensor WARNING Handle the coolant temperature sensor with special care. Never subject the coolant temperature sensor to strong shocks. If t ...

    Other materials:

    Checking the timing chain tensioner
    1. Check: Timing chain tensioner Cracks/damage/rough movement Replace. a. Lightly press the timing chain tensioner rod into the timing chain tensioner housing by hand. NOTE: While pressing the timing chain tensioner rod, wind it clockwise with a thin screwdriver "1" until it stops. b. ...

    Avoid Carbon Monoxide Poisoning
    All engine exhaust contains carbon monoxide, a deadly gas. Breathing carbon monoxide can cause headaches, dizziness, drowsiness, nausea, confusion, and eventually death. Carbon Monoxide is a colorless, odorless, tasteless gas which may be present even if you do not see or smell any en ...

    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 ...

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