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)

Or, hide this message: temporarily or permanently

Valve Spring

Compression Pressure @ Height
Test, Intake and Exhaust
396.0 N @ 25.5 mm
(89.0 lbs @ 1.0 inch)
Installed, Intake and Exhaust
177.0 N @ 34.5 mm
(39.8 lbs @ 1.36 inch)

Service Limit
Pressure Loss @ Specified Height 10% @ Specified Height