Yamaha YZF-R125 Service Manual: Intake air pressure sensor

1. Check:

  • Intake air pressure sensor output voltage Out of specification Replace the throttle body.

a. Connect the pocket tester (DC 20 V) to the throttle body sensor assembly coupler as shown.


  • Positive tester probe
    pink/white "1"
  • Negative tester probe
    gray/black "2"

Intake air pressure sensor


b. Set the main switch to "ON".

c. Measure the intake air pressure sensor output voltage.

    Throttle position sensor
    1. Check: Throttle position sensor a. Connect the digital circuit tester to the terminals of the throttle body sensor assembly coupler as shown. Positive tester probe → gray/red t ...

    Intake air temperature sensor
    1. Check: Intake air temperature sensor resistance Out of specification Replace the throttle body. a. Connect the pocket tester ( × 1k) to the throttle body sensor assembly co ...

    Other materials:

    Installing the starter clutch
    1. Install: Starter clutch assembly Starter clutch bolts "1" NOTE: While holding the generator rotor "2" with the sheave holder "3", tighten the starter clutch bolts. Do not allow the sheave holder to touch the projection on the generator rotor. Stake the end "a" of each start ...

    Checking the transmission
    1. Measure: Main axle runout (with a centering device and dial gauge "1") Out of specification Replace the main axle. 2. Measure: Drive axle runout (with a centering device and dial gauge "1") Out of specification Replace the drive axle. 3. Check: Transmiss ...

    Protective apparel
    The majority of fatalities from motorcycle accidents are the result of head injuries. The use of a safety helmet is the single most critical factor in the prevention or reduction of head injuries. Always wear an approved helmet. Wear a face shield or goggles. Wind in your unprotecte ...

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