Yamaha YZF-R125 Service Manual: Troubleshooting

The ignition system fails to operate (no spark or intermittent spark).

NOTE:

  • Before troubleshooting, remove the following part(s):

1. Seats

2. Fuel tank

3. Right side cover

4. Left side panel

5. Left upper side cowling

Troubleshooting


Troubleshooting


    Circuit diagram
    2. Crankshaft position sensor 4. Main fuse 5. Main switch 8. Sidestand switch 9. Battery 17.Engine stop switch 23.Lean angle sensor 25.ECU (engine control unit) 26.Ignition coil 27.Spark ...

    Electric starting system
    ...

    Other materials:

    Checking the rocker arms and rocker arm shafts
    The following procedure applies to all of the rocker arms and rocker arm shafts. 1. Check: Rocker arm Damage/wear Replace. 2. Check: Rocker arm shaft Blue discoloration/excessive wear/pitting/ scratches  Replace or check the lubrication system. 3. Measure: Rocke ...

    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 front wheel
    1. Check: Front wheel axle Roll the wheel axle on a flat surface. Bends → Replace. WARNINGDo not attempt to straighten a bent wheel axle. 2. Check: Tire Front wheel Damage/wear → Replace. Refer to "CHECKING THE TIRES" on page 3-23 and "CHECKING TH ...

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