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:

    Faulty lighting or signaling system
    Headlight does not come on - Wrong headlight bulb - Too many electrical accessories - Hard charging - Incorrect connection - Improperly grounded circuit - Poor contacts (main or light switch) - Burnt-out headlight bulb Headlight bulb burnt out - Wrong headlight bulb - Faulty battery - Fau ...

    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 ...

    Removing the valves
    The following procedure applies to all of the valves and related components. NOTE: Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure the valves properly seal. 1. Check: Valve sealing Leakage at the valve seat Check the valve ...

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