Yamaha YZF-R125 Service Manual: Checking the spark plug

1. Remove:

  • Right side cover Refer to "GENERAL CHASSIS" on page 4-1.

2. Disconnect:

  • Spark plug cap

3. Remove:

  • Spark plug
CAUTION:

Before removing the spark plug, blow away any dirt accumulated in the spark plug well with compressed air to prevent it from falling into the cylinder.

4. Check:

Spark plug type Incorrect →Change.


5. Check:

  • Electrode "1" Damage/wear→ Replace the spark plug.
  • Insulator "2" Abnormal color→ Replace the spark plug.

    Normal color is medium-to-light tan.

6. Clean:

  • Spark plug (with a spark plug cleaner or wire brush)

7. Measure:

  • Spark plug gap "a" (with a wire thickness gauge) Out of specification → Regap.

Checking the spark plug


8. Install:

  • Spark plug

NOTE:

Before installing the spark plug, clean the spark plug and gasket surface.

9. Connect:

  • Spark plug cap

10.Install:

  • Right side cover Refer to "GENERAL CHASSIS" on page 4-1.
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    Other materials:

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    1. Check: Decompression system a. Check the decompression system with the camshaft sprocket and the decompression cam installed to the camshaft. b. Check that the decompression lever "1" moves smoothly. c. Without operating the decompression lever, check that the decompression cam " ...

    Specifications
    Dimensions: Overall length: 2015 mm (79.3 in) Overall width: 660 mm (26.0 in) Overall height: 1065 mm (41.9 in) Seat height: 818 mm (32.2 in) Wheelbase: 1355 mm (53.3 in) Ground clearance: 155 mm (6.10 in) Minimum turning radius: 3100 mm (122.0 in) Weight: With oil and fuel: 138.0 k ...

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