Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Spark Plug: Testing and Inspection

CAUTION:
- When service the iridium / platinum spark plugs (slender center electrode type plugs), i.e. IFR5J11, IFR6511, do not touch the center electrode to avoid damage to it. The electrode is not strong enough against mechanical force as it is slender and its material is not mechanically tough.
- Do not clean or adjust gap for the iridium / platinum spark plugs.
- Electrode wear
- Carbon deposits
- Insulator damage
- Air gap

If any abnormality is found, replace them with specified new plugs.

Spark plug air gap "a": 1.0 - 1.1 mm (0.040 - 0.043 in.)

Spark plug type
NGK: BKR6E11 / IFR5J11 / IFR6J11
DENSO: SK16PR11 / SK2OPR11 / K2OPR-U11






NOTE: NGK IFR5J11 is highly recommended for better engine starting performance under -25 °C (-13 °F).