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Autolite 4100 tuning

3610 Views 5 Replies 3 Participants Last post by  Ivy66GT
Hey guys, I have a 66 289 with an Autolite 4100 and trying to set the fuel/air mixture. Has anyone experienced that even with the screws all the way in they engine will still run and not stumble? The advance is set at about 800 and with the vacuum advance off.
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Your primary or secondary throttle plate is/are probably open to far and the car is not really running on the idle circuit but gettings its fuel through the main jets. The adjustment screws only control fuel through the idle circuit. If it idles with those closed then your fuel is coming from somewhere else; main jets, leaking power valve, etc.
That what I was thinking, the car sat for about 7 years in my brothers garage before I bought it from him. I did pull the carb to see if any of the butterflies were stuck open but were all shut. Guess I'll have to overhaul the carb to make sure and clean out all that ethanol residue, etc.

Thanks Ivvy
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