Are all holley air/idle screws set 1 1/2 turns out or are the double pumpers diff? And i have a 600 holley with vac secondaries and electric choke.Ive rebuilt it and it runs better just not like it should so im getting anew one.I need suggestions. These are two sep questions.

 

According to the Holly instruction manual,
[ol][*]Adjust each idle mixture screw (Figures 10 & 11) 1/8 turn at a time, alternating between each screw. Turn them equally, until you achieve the highest possible vacuum reading without adjusting the curb idle speed screw. Turn screws in to lean the mixture. Turn them out to richen the mixture. [/ol]
The appropriate manual for your carburator can be downloaded at: http://www.holley.com/TechService/Instructions.asp

Of course, you will need a vacuum gauge to do this. I have followed these manuals and tuned my holley o.k.

 

There were some with reverse idle circuits...don't remember which ones. Probably won't matter anymore since I think all new ones are standard. But if you are working on one from the early -mid 70's it may be worth checking.

 

I kno that point but i wanna kno where they start from the factory cuz i kno my 600 is 1 1/2 out to start

 

The holley rebuild instructions that came with myHolley rebuild kitsay to start at 1 1/2 turns out, but I always start with mine fully in and slowly turn out until I reach the highest vacuum. It will run really rough at first but this way you are not running too lean. I am pretty sure it makes no difference were you start as long as you adjust them properly.

 

thanks thats where ill start.