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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Servo Diaphragm




1. Connect a suitable tachometer to the engine.
2. Operate engine and ensure engine idles properly. Switch engine off and remove air cleaner.
3. Disconnect vacuum hose from servo diaphragm. Connect a suitable vacuum hose between intake manifold and servo diaphragm. Start engine and increase engine speed to 2000 RPM with throttle lever, then release throttle lever and ensure engine speed is 1100 to 1300 RPM, adjusting as necessary.