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

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

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Spark Test


Spark Test

1. Disconnect the spark plug wires, one at a time, from each spark plug.





2. Hold each insulator with pliers 0.20-0.40 in (5-10 mm) from a ground.
3. Crank the engine and verify that a strong blue spark is visible.

* NOTICE: Be sure the socket is fitted squarely over the spark plug.