Yamaha YZF-R125 Service Manual: Gaskets, oil seals and o-rings

1. When overhauling the engine, replace all gaskets, seals and O-rings. All gasket surfaces, oil seal lips and O-rings must be cleaned.

2. During reassembly, properly oil all mating parts and bearings and lubricate the oil seal lips with grease.

Gaskets, oil seals and o-rings


  1. Oil
  2. Lip
  3. Spring
  4. Grease
    Replacement parts
    Use only genuine Yamaha parts for all replacements. Use oil and grease recommended by Yamaha for all lubrication jobs. Other brands may be similar in function and appearance, but inferior in qua ...

    Lock washers/plates and cotter pins
    After removal, replace all lock washers/plates "1" and cotter pins. After the bolt or nut has been tightened to specification, bend the lock tabs along a flat of the bolt or nut. ...

    Other materials:

    Checking the diode
    1. Check: Diode Out of specification Replace. NOTE: The pocket tester or the analog pocket tester readings are shown in the following table. a. Disconnect the diode from the wire harness. b. Connect the pocket tester ( × 1) to the diode terminals as shown. c. Check the diod ...

    Checking the bulbs and bulb sockets
    NOTE: Do not check any of the lights that use LEDs. Check each bulb and bulb socket for damage or wear, proper connections, and also for continuity between the terminals. Damage/wear  Repair or replace the bulb, bulb socket or both. Improperly connected Properly connect. No c ...

    Checking the valve springs
    The following procedure applies to all of the valve springs. 1. Measure: Valve spring free length "a" Out of specification Replace the valve spring. 2. Measure: Compressed valve spring force "a" Out of specification Replace the valve spring. b. Installed length 3. ...

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