Yamaha YZF-R125 Service Manual: Checking the cooling system

1. Remove:

  • Side covers
  • Upper side cowlings Refer to "GENERAL CHASSIS" on page 4-1.

2. Check:

  • Radiator "1"
  • Radiator inlet hose "2"
  • Radiator outlet hose "3"

Coolant reservoir hose "4"

Water pump breather hose "5" Cracks/damage → Replace.

Refer to "RADIATOR" on page 6-1.

Checking the cooling system


3. Install:

  • Upper side cowlings
  • Side covers Refer to "GENERAL CHASSIS" on page 4-1.
    Checking the coolant level
    1. Stand the vehicle on a level surface. NOTE: Place the vehicle on a suitable stand. Make sure the vehicle is upright. 2. Check: Coolant level The coolant level should be between the max ...

    Changing the coolant
    1. Remove: Lower side cowlings Refer to "GENERAL CHASSIS" on page 4-1. 2. Remove: Radiator cap "1" WARNINGA hot radiator is under pressure. Therefore, do not remove t ...

    Other materials:

    Removing the cylinder head
    1. Align: "I" mark "a" on the generator rotor (with the stationary pointer "b" on the generator cover) a. Turn the crankshaft counterclockwise. b. When the piston is at TDC on the compression stroke, align the "I" mark "c" on the camshaft sprocket with the mark "d" on the cylinder h ...

    Troubleshooting charts
    Starting problems or poor engine performance Starting problems or poor engine performance Engine overheating WARNING Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be blown out under pressure, which could cause serious injury. Be ...

    Checking the front brake master cylinder
    1. Check: Brake master cylinder Damage/scratches/wear Replace. Brake fluid delivery passages (brake master cylinder body) Obstruction Blow out with compressed air. 2. Check: Brake master cylinder reservoir Cracks/damage Replace the brake master cylinder. Brake maste ...

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