idles high

[Lespaul59]

Any way to turn the idle down on a 600 holley? Everything is plugged and I even turned out the fuel some more at idle.The idle screw itself is backed all the way out. Maybe I'll have to retard the timing. It runs perfect where I have the timing so I hope it doesn't affect anything. Any suggestions?

[spencerforhire]

The first couple of things that come to mind are 1- vacuum leak; 2- bent primary or secondary throttle blades. If neither 1 or 2 is the case, there are other solutions- If the idol drops to where you want it with the vacuum line to the distributor unplugged, try plugging it into the ported vacuum port on the carb instead. It's ABOVE the throttle blades and won't let the timing advance until the throttle is partially open.

[Rickracer]

I really would not go to ported vacuum to solve a high idle problem. There is a secondary idle stop screw on the passenger side of the baseplate. You may have to take the carb off to access it, but I can usually grip it with a pair on needle nose pliers to move it a bit, perhaps half a turn or so should be enough to get you in range with the primary adjustment. It's also possible that the secondary throttle shaft isn't closing all the way. there is a link on the throttle side of the carb that connects the primary shaft to the secondary throttle shaft, at closed throttle, that link should also push the secondary throttle shaft closed, make sure it's doing that.

[spencerforhire]

Rick is right about the ported vacuum thing; it's not a perfect solution, just a "band-aid" fix. The best way to check is pull the carb off and hold it up to the light to see if all 4 throttle plates are closing tightly.

[Lespaul59]

Retarted the timing just slightly to get the idle right. Still runs great. Had to change the power valve from a 6.5 to a 5.5 cause I got a .470 lift cam and had a problem of surging while at cruise.