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Thread: Tuning ideas for 4776 DP on a 327.

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  1. #11

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    Thanks as always for the quick reply! Just to be clear, this happens on the 1850-2 and the 4777 DP. And only when 1) Idle air screws are set to less than 1.5 turns. 2) When accelerating with some spirit, the gas pedal is let off and the clutch pedal is depressed.

    If shifted below 3000 RPM, driving more gently, this does not occur. Just when driving with more pedal. At 3000 RPM, my centrifugal advance is all in. When clutch pedal is depressed My vacuum advance will be all in, 8°-9° advance with my current limiter. That would give me 35°-36° + 8°-9°. Roughly 44° advance which gets me no trailer hitching or pinging.

    I can eliminate this pop by turning the screws to 1.75 turns or greater even though max vacuum at idle is 1 to 1.25 turns. I feel the primary jets are a touch lean at 66. In no way does this contribute to my issue? I’m planning on trying 68s regardless. Rob
    Last edited by H.O.rider; 06-15-2019 at 10:38 AM.

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