Like the ***le says,freshly rebuilt 600 cfm(4160) on a 305 has a dead spot off idle. Air screws at 2 1/2 turns,floats set.Any advice?
I had that same problem with a Holley I had on a 350 in a Nova. Tried everything, even took it to a dyno and never could find out the problem. That was the last Holley I ever owned and that was back in 1972.
The check ball under the acc pump and the red flapper do the same thing. It's "either/or", doesn't use both. There is supposed to be another check ball under the squirter too. Larry T
your air and fuel mixture screw's are to far out...for your app all you need is a 1 1/2 turn's out...they also have different size power valves or you have a faulty one to begin with. if the rebuild kit is old the power valve could be no good.
Check and make sure you have a .015"-.020" clearance between the acc. pump arm and the pump cam lever at wide open throttle... You need feeler gages and a 3/8" and a 7/16" wrenches to make the the adjustment... Let us know how it worked out...
the check ball is inside the accelerator pump casting in the primary blow. It is held in place with a br*** strip. The ball should be loose. Check the float bowl gasket accelerator pump hole alignment with the metering block. Check the metering block to body accelerator pump hole alignment. It may have the transfer pipe. The check valve under the accelerator pump discharge nozzle should be loose. Check the discharge nozzle openings for a restriction. For some reason some engines respond to the hollow accelerator pump discharge screw. Now the linkage: when you open the throttle slightly the arm riding on the plastic cam should move quite a bit to activate the accelerator pump arm. You can shift this plastic cam to another hole or flip it to make the linkage more responsive. There should be no slop or free play in the accelerator pump linkage. Open the throttle and check the distance between the pump arm and the adjusting screw. Push in the arm and a medium paper clip should slide between them. Adjust the screw for clearance. You also need to check for any vacuum leaks around the carb. Vacuum advance working?
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