"In general", if your six pack is idling high, then the carburetors aren't fully closed. A very common issue is the return linkage rods which could be holding one or more of the carburetors slightly open at idle. I would suggest you start by disconnecting the clips on the end carburetors & making SURE your center carburetor is completely closed & the return spring is reasonably stiff. Then, close the outer carburetors fully by hand & re-insert/re-clip the return rods one at a time. When those two rods are adjusted correctly, they should just slip right into the hole(s) of the outboard carburetors with no effort at all. HOPE THIS HELPS