Yamaha YZF-R125 Service Manual: Checking the throttle body

1. Check:

  • Throttle body Cracks/damage Replace the
    throttle body.

2. Check:

  • Fuel passages Obstruction Clean.

a. Wash the throttle body in a petroleum-based solvent.

Do not use any caustic carburetor cleaning solution.

b. Blow out all of the passages with compressed air.

    Removing the throttle body
    1. Extract the fuel in the fuel tank through the fuel tank filler hole with a pump. 2. Disconnect: Fuel hose WARNINGCover the fuel hose connections with a cloth when disconnecti ...

    Installing the throttle body
    1. Install: Throttle body joint clamps NOTE: Align the projections "a" on the throttle body joint with the slot "b" in each throttle body joint clamp. 2. Install: Throttle body joint ...

    Other materials:

    Checking the rear brake caliper
    1. Check: Brake caliper piston "1" Rust/scratches/wear Replace the brake caliper piston. Brake caliper cylinder "2" Scratches/wear Replace the brake caliper assembly. Brake caliper body "3" Cracks/damage   Replace the brake caliper assembly. Brake fluid deli ...

    Checking the piston rings
    1. Measure: Piston ring side clearance Out of specification Replace the piston and piston rings as a set. NOTE: Before measuring the piston ring side clearance, eliminate any carbon deposits from the piston ring grooves and piston rings. 2. Install: Piston ring (into the cylind ...

    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 coupler as shown. Positive tester probe brown/white "1" Negative tester probe gray/black ...

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