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:

    Fuel
    Make sure there is sufficient gasoline in the tank. WARNING Gasoline and gasoline vapors are extremely flammable. To avoid fires and explosions and to reduce the risk of injury when refueling, follow these instructions. Before refueling, turn off the engine and be sure that no on ...

    Checking the relays
    Check each switch for continuity with the pocket tester. If the continuity reading is incorrect, replace the relay. 1. Disconnect the relay from the wire harness. 2. Connect the pocket tester ( × 1) and battery (12 V) to the relay terminal as shown. Check the relay operation. Out ...

    Checking the crankshaft position sensor
    1. Disconnect: Crankshaft position sensor coupler (from the wire harness) 2. Check: Crankshaft position sensor resistance Out of specification  Replace the crankshaft position sensor/stator assembly. a. Connect the pocket tester ( × 100) to the crankshaft position sensor c ...

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