[guzzijohn]

Had ignition/idle issue that turned out to be cracked,leaky plug caps. Fixed that w 'Dip It' vinyl coating. Before the fix idle screws had some effect on running although miss wouldn't go away. After-engine runs smooth but idles best w screws shut. Carbs are clean and runs great w plenty of power. Just a wandering/persistent Gremlin!

GJ

 

[CXPHREAK]

With the mixture screws closed the mixture may be being pulled through perforated ACVs?

 

[Eurovee]

Yeah, failure to respond to idle mixture screw adjustment is a classic symptom of perforated air cut-off diaphragms.