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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Engine Knocks


1. Check ignition timing and adjust as necessary. If timing is satisfactory, proceed to step 2.
2. Check spark plugs for an excessively hot operating condition. If a hot condition exists, install a colder type spark plug.
3. Check distributor governor spring and pin hole in governor. Connect or replace governor spring assembly and governor pin, if necessary.