Holley with excessively lean light throttle cruise

[F-BIRD'88]

When you drill the air bleed 1/16" be sure to BEVEL that fresh drill hole a bit front and rear to just smooth off the sharp drilled edge on the drilled hole.
Hone it by hand a bit with a slightly bigger drill bit.
This ensures that your DIY home drilled .062" air bleed will flow fuel the same as a store bought holley air bleed does.
It needs that slight entry exit bevel.
Not too hard to do.
Compare to one of your holley Air bleeds f&r for reference.

[Ken_Parkman]

An update:
This has been a tremendous education. The secondary idle speed screw is a massive influence. Close it down and now the carb works quite well, cruise is now 14.5-15 on the AFR, no more surge and bucking. Also jetted down 4 numbers all around. Full power may be a bit lean and I may go back up a bit - this is worth a trip to the track or chassis dyno.

The Rambler is a little blue 69 2 door post, dog dish hubcaps. Go to St Thomas every once and a while, but not in the last few years.

[Walter R. Malik]

An update:
This has been a tremendous education. The secondary idle speed screw is a massive influence. Close it down and now the carb works quite well, cruise is now 14.5-15 on the AFR, no more surge and bucking. Also jetted down 4 numbers all around. Full power may be a bit lean and I may go back up a bit - this is worth a trip to the track or chassis dyno.

The Rambler is a little blue 69 2 door post, dog dish hubcaps. Go to St Thomas every once and a while, but not in the last few years.

YES ...if the secondary plate opening is not correct for the application, the carb will present all kinds of unwanted issues.

Different applications will want the secondary idle opening to be "just cracked" merely so they don't stick to an opening "barely below the slot"; which is usually quite a difference.

[Roadknee]

. " The 076 idle air bleeds should be fine."

Based on what ? We don't even know the carb list number or what the original size IAB was. Are they screw in bleeds or pressed in? Most of these older carbs were pressed in bleeds. Have you seen a lot of Holley carbs with .076" IAB's ?
More info is what is needed.

My recommendation was based on experience including plenty of Holley’s with 076-078 primary IABs that work great. We can now add this one to the list.

[HQM383]

An update:
This has been a tremendous education. The secondary idle speed screw is a massive influence. Close it down and now the carb works quite well, cruise is now 14.5-15 on the AFR, no more surge and bucking. Also jetted down 4 numbers all around. Full power may be a bit lean and I may go back up a bit - this is worth a trip to the track or chassis dyno.

The Rambler is a little blue 69 2 door post, dog dish hubcaps. Go to St Thomas every once and a while, but not in the last few years.

Great result. How much did you close it down, or how open in relation to secondary transfer slots? Are transfer slots secondary same dimensions or shorter than primary?

[Ken_Parkman]

Secondaries completely closed. Nowhere close to the transfer slot. Tried to open them back up a bit and immediately back into lean cruise.

[HQM383]

Secondaries completely closed. Nowhere close to the transfer slot. Tried to open them back up a bit and immediately back into lean cruise.

Hints at little to no fuel from secondary idle/transfer. See how it responds opening the secondaries. But hey, if it’s working now for what you’re doing then all good.

To clarify all that’s covered so far is it an 80513 1000cfm?

[rgalajda]

. " The 076 idle air bleeds should be fine."

Based on what ? We don't even know the carb list number or what the original size IAB was. Are they screw in bleeds or pressed in? Most of these older carbs were pressed in bleeds. Have you seen a lot of Holley carbs with .076" IAB's ?
More info is what is needed.

My recommendation was based on experience including plenty of Holley’s with 076-078 primary IABs that work great. We can now add this one to the list.

I apologize for being a little abrupt in my post. At least we agreed on the closing of the secondary.

[Bob Hollinshead]

An update:
This has been a tremendous education. The secondary idle speed screw is a massive influence. Close it down and now the carb works quite well, cruise is now 14.5-15 on the AFR, no more surge and bucking. Also jetted down 4 numbers all around. Full power may be a bit lean and I may go back up a bit - this is worth a trip to the track or chassis dyno.

The Rambler is a little blue 69 2 door post, dog dish hubcaps. Go to St Thomas every once and a while, but not in the last few years.

Instead of jetting up for the richer full power ratio you need---you can enlarge your power valve channel holes. This way it will maintain the leaner cruise ratio.

[Geoff2]

This post is another great example of the fact that the T slot position is the foundation for setting up the idle & low speed cruise.