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

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Testing Notes

NOTE: To provide accurate results, it is essential that the calibration of your engine analyzer be maintained. Refer to your equipment manual. If this is not available, an estimate of the calibration can be made by connecting the spark tester (Ford Part# D81P-6666-A, or equivalent) to a properly operating ignition system and measuring the firing voltage of the spark tester only. Do not include the firing voltage of the rotor to cap clearance. The spark tester firing voltage should be approximately 28 Kv.