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

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Spark Plug: Testing and Inspection

SPARK PLUG DEFECTS:

1. Normal ignition voltage spike: spark plug OK.
2. Low ignition voltage spike: Small electrode gap.
3. High ignition voltage spike: Large electrode gap.

Evaluation of combustion period at idle speed:

- Normal combustion period : Spark plug OK.

- Long combustion period: Small electrode gap.

- Short combustion period: Large electrode gap.