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An initial setting might be available but it really needs to be tuned to the combo, which would be unique to your setup.

Dual quad tuning



iagree This!


The mixture screws on the secondary (front) carburetors are there to provide a little fuel to the forward cylinders to keep them from going lean at idle, this is why they were factory set and plugged off as an anti-tamper measure. Once set they won't usually vibrate out unless someone has modified or damaged the screws or holes making them overly loose.