holley 600 help

[mean350]

how do you set the idling on a holley 600cfm carb? thanks a bunch

[SWIGIN]

with the idle screw on the left side.....no joke

if you mean the air screws what i do is turn them in slowly till the motor starts to stumble then go out till it stumbles and put it right in the middle

[mean350]

thers only 1 screw for the idle then? i though it was the screws that are on each side of the carb,.

[SWIGIN]

those are the air screws

[SWIGIN]

http://www.holley.com/

this will help

[mean350]

thanks!!!!!!!

[MO dx]

If you were closer thats what my specialty setting up carbs on hotrods.

[bondoboy]

Gently turn both idle mixture screws in until they bottom out. Back each one out 1and 1/2 turns. Hook a vacuum gauge to a full manifold vacuum source. Start the engine. Back each screw out the same amount until you get the highest vacuum reading. If you go too far, the vacuum will drop and you will have to turn them in a little bit. Then, set your idle speed with the screw on the throttle linkage.

[mean350]

which vacuum? i cant leave it running it revs so high

[bondoboy]

A full vacuum port would be in the baseplate of the carb, like the port your modulator line runs to for an auto transmission. Is your whole problem the high idle? A vacuum leak in the carb to intake gasket will make it run too fast. Is the fast idle turning off when the engine warms up? Do you have an electric choke? Is your idle speed screw turned in too far? Your idle speed screw is on the linkade near where the throttle cable hooks up. Screwing it in simply opens the throttle. Is your throttle returning to the closed position? Usually the stock throttle cable bracket will not put the proper tension on the spring and engine vacuum will crack the throttle. If this is the case, holley makes a bracket. Let me know if you need more help.

[mean350]

there is no port in the baseplate of the carb. theer is just 2 of them on the side. the idle screw is turned the whole way out and it is not sticking anywhgere. its a manual choke. the throttle is returning fine.i dikdnt look at it whikle the engine is running cause the idle is so high. when i firdst fire it up it aint bad then it revs like crazy.

[bondoboy]

Is your carb a single fuel line vacuum secondary? What model number is stamped on the choke tower? Is it 1850? You should have an 11/32 vacuum port on the base for the PCV hose and there should be a small port at the front of the carb on the passenger side. If you have the choke off and tap the throttle, do the rpm's come down? Your fast idle may be set too high. I would almost bet it's the fast idle or you have a vacuum leak. What kind of vehicle is this on? Is the carb new? Did you just install it?

[mean350]

no its not an 1850. its like 6... and no the rpms does not come down when i hit he gas. how do i adjust the fast idle?

[mean350]

its a 6520

[cr480r]

how do i adjust the fast idle?

The fast idle is usually part of the choke linkage... shouldnt matter unless the chock is engaged. It sounds to me like a your throttle is hung open(most likely improper cable or bracket), or your curb-idle is just set way too high. If you look at the lingage you will see the curb-idle adjuster... then peek down inside the carb and look to see if the throttle blades are closing. the secondaries can hang open too... After you get it to idle down to a reasonable level... then follow the methods described by bondoboy for adjusting the idle-mixture adjustment screws... That is how I do them...and probably the easiest for those that havent developed a feel for it.