Hi Everyone,
I just installed a Holly 4160-390 cfm 4bbl and Offy dp manifold on my modified 22r. The eng runs real strong off idle to red-line, but I can't get any idle adjustment 1200 rpm is the lowest I can get it to run. Checked and there is no vacuum leaks. Hoping someone in this group has gone down this road and can help me in the tuning problem. TIA Dave
Is this a new carb or one that you have built up?
These following checks, of course, are after looking over the linkage to see if there are any binds preventing the linkage from fully seating.
Have you replaced the power valve?
Does pressure on the linkage toward the idle stop reduce the idle speed? If so, try more spring pressure.
Double check to ensure that you are not hanging on the fast idle cam. It is on the passenger side of the carb and the adjustment is made with a 1/4" open or box end wrench with the linkage opened all the way. (Do not adjust it with the engine running ;) ). It should be set for the second step to give 1500RPM.
Also check to ensure that the secondary butterflies are correctly adjusted.
RD
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