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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Deceleration Valve: Testing and Inspection




1. Open throttle valve fully, then push dashpot rod with finger and check that rod goes into dashpot slowly.
2. Release rod and check that rod comes out quickly.
3. If dashpot rod does not operate as described, adjust as follows:
a. Warm engine to normal operating temperature and run at idle.
b. Connect tachometer to engine.
c. Increase engine speed to 4000 RPM.
d. Slowly decrease engine speed and check that dashpot rod contacts lever at 3200-3800 RPM.
e. Loosen locknut and adjust by turning dashpot, if necessary.