Spica lean out?

[eparise@domain.elided]

Probably a dumb question; but, the 69 Duetto (1750) seems to be running
very rich. Difficult to start and when it finally does start and warm up,
it doesn't run very smooth (but it used to). Also, when revving the engine
and letting up quickly on the throttle, it bangs to beat all hell. Have
pulled the new plugs and always find them very black and sooty. Can anyone
offer suggestion(s)? Thanks

69 Duetto
88 Verde
91 164L
etc, etc
Ed Parise
Churchville, VA

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