blackandgoldl69

ok so i have the original l69 305 in my car with an accel hei distributor and accel super coil also an edelbrock rpm performer manifold and a Holley 600cfm carb my question is how do i go about tuning this carb it has a tuning screw on either side of the carb towards the front of the car which screw is which and how many turns do they get to make it somewhat driveable it is running super rich right now

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fleetmgr

See the sticky at the top of the forum about Holley tuning.

blackandgoldl69

already read it and still confused lol

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fleetmgr

OK, the two little horizontal screws (one on each side) are your idle mixture adjustments. The screw on the throttle linkage is idle speed.

You'll need the following:
1. 5/8 box end wrench for the float adjustment.
2. Large flat blade screwdriver for the float adjustment.
3. Small flat blade for the idle mix screws.
4. Tachometer

Start the car, let it warm up at idle
On the float bowls, there is either a clear plastic plug or a large screw. If it's the large screw, remove it. If the fuel level in the float bowl is correct, it should JUST trickle out. If it's the clear plug, you should JUST be able to see the fuel level at the bottom of it. In either case, if you can't then you need to adjust the float level. Using the 5/8 wrench and the big screwdriver...put the box end on the nut on top of the float bowl, and using the screwdriver loosen the screw. The screw is what locks the adjusting nut. Loosen the screw just enough to turn the nut, and turn the nut CCW to increase the fuel level, or CW to decrease it about 1/4 turn, then immediately tighten the screw. When you loosen the screw, expect a little fuel to leak out. Now, look at the hole/plug on the side. Once fuel is JUST visible, you're done with this part. Turn car off.

Hook up your tach. Now close the small horizontal screws (idle mix screws), but do not tighten them down. IF you do, you will damage the carb internally. Just lightly seat them, then back each one out about 3 full turns. Start the car, let it idle. Watching the tach, set your idle speed using the speed adjust screw. Now turn one of these idle mix screws in until you see the RPM increase slightly. Do the same on the other side. If idle rpm increases slightly, and then decreases again you went too far. Back it out just a bit and repeat, stopping at the highest idle speed. If at any time, idle rpm goes too high (above 900 or so), slow it down with the idle speed screw to a normal idle speed (see tune specs for your car) before continuing.

Now, using the screw on the throttle linkage, set your idle speed one final time.

You're done!!