how is it doing so far

I took the idle screws out and sprayed in the starting fluid. I couldn't really tell if it made any difference. I held my hand over the choke area nd if I got a good seal it raised the RPM so I went from 2 turns out to 2 1/2. Better but same test= same results. I ended up at 3 1/2 turns.

That would seem to indicate a vaccum leak. The idle now smells rich but it holds steady and returns well. I took a spin and it flet much better.

I forgot to tune the secondaries , that might make a differnce at speed but the idle mixture made it much better overall.

I was able to turn the idle speed screw quite a bit after richening the mix, now holding pretty solid at 850.

I still seem to have the off idle stumble some. I think there is something in that circuit as it isn't a constant problem. Will almost bog enough to die in first sometimes.

Yes, I checked the level and drop both today.

I have gas but the stumble is intermittent so...
Earlier today I had no gas so what I did when I broke it back down was an improvement. Has the shooter from the other carb in it now.

The air door setting is 2 turns after slack is taken up. That is for all AVS carbs. Looks like that won't work here and really I think that is the baseline and every engine wuld need some tuning from there.

I think 3 turns would be worth trying on the idle mix. 3.5 seems like a lot for a mostly stock engine.

You might tighten up the air door several more turns just to take the secondaries completely out of the picture as this(appears) to be a pri system problem or even removing the secondary link so the secondary throttles dont even open(kind of brainstorming on that) but anything to eliminate/narrow down the problem but keepin it simple I would lean the idle mix screws a bit & mainly concentrate on the AP system especially after what you did so far made a dramatic improvement. I'd check for immediate tip in, that the plunger lever is in the hole furthest from the fulcrum then readjust the plunger to max height & possible enlarging the shooter nozzles

Here's the rub-

It would havemade much more sense to just swap rods, fix idle screw adjustments and then deal with the hanging idle on the other 4966. I can't believe I messed that opportunity up.

That carb shot gas out w/o issue at all. So enlarging anything on this one seems out of wack. In fact the shooter from the other carb is in it so that leaves the circuit in the body messed up somehow.

yeah but didn't you say that the idle mix threads on the other one were cross threaded or something (it sounded bad )

It was stripped and I retapped it. The screw went in OK. I bet you could baseline it with the carb off and eyeball or in some way measure the tip of the screw sticking out.

The hot idle compensator is missing from that one, could be the hanging idle problem.

I also have a 69 383 stick trans AVS also but that one has the tip of a brass idle mix screw broken off in it.

Hopefully I can get the pump shot right on this carb. I think the air door thing will be no problem at all.

The idle hang on the other carb could be worn primary shaft in the carb body causing the misalignment , this is why 40 year old carbs belong on show poodles that get pushed on and off trailers .

[swingin/72] Just buy a Holley 750 DP and be done with it [/swingin/72]

I'll take donations so you all don't have to endure this anymore

I tuned the air door and that seems to have come around. Slight bog then takes off well.

I tend to think the bog might be from that missing pump shot. I'm going to try the lever in the top hole and see if that generates enough shot to work. i noticed that the arm was in the top hole when i took the carb apart yesterday. The middle hole should be all that is needed but since this isn't working...

I turned the idle mix in 1/2 a turn and reset the speed. Seems OK. An interesting thing is that the cam now sounds much more choppy. The Eddy idled so smooth you would almost not hear any of te overlap.

Engine still isn't as smooth as the Eddy carb had it at cruise but is not as bad as it was.

I think I have the secondaries about as close as they will get to perfect.

The top hole adjustment helped the stumble but I still feel it. When i flushed it nothing came out of the tunnel and I sprayed from both the accel pump side and the shooter side.

Not sure what to do about that now. I could drill one of the three shooter i have but I don't think it is going to help since you still need fuel there to come out.

Maybe try another accel pump???

In the troubleshooting section on edelbrocks site, they mention that an off-idle stumble is usually caused by the idle mixture screws being too rich, or too lean.

I really think it is that I'm not getting any shot immediately for some reason. I've had the stumble with the idle so rich it smelled rich and with the idle so lean it barely ran.

I'd continue to search for why there's no squirt on tip in, maybe check the brass weight under the shooter and the gasket for starters. Since you have several shooters to play with you might drill one a few thou larger since that is the restriction AFTER tip in is reestablished

I don't think there was a brass weight under the shooter. New gasket.

I went out and looked. Sure enough there is a needle that was in the other carb. When I took it out, it looked like I remember the one on the car looking.

I looked all over the bench and in the pan that I cleaned and didn't find a check ball or a needle. The exploded view said you can have either one.

Since the pump shot was in the top hole when i dug into it, I bet that was a mask for the missing part from a prior rebuild. It is better with the bigger shot.

If this makes the one on the car as responsive as the mucked up one, we will have a pretty good piece. Thanks Robert.

Installed the needle in the accel pump circuit-

Noticed it still had a stumble off idle at first. Seemed to get better after running awhile but it was nearly fully warmed when i took off from the house so...?

Car is running smoothly down the road.

WOT doesn't have the bog the 750 Eddy AFB had BUT it doesn't pull near as hard either. I checked the WOT adjustment and with some weight on the pedal it is about 1/16th short of full open. I would like to check with a helper tonight and see what I think, the weights are hard to wedge and I don't have the old 2x4 I used to use as a dead man anymore.

Drone seems less with this carb. Maybe harmonics changed with the smaller butterfly's.

Idle sounds wicked now. I don't understand why the Carter does this and the Eddy was smooth. Anybody have any ideas why that would be?

I will be testing going back to the top hole for a bigger pump shot. Also will try a K&N filter in the current breather(open) and then with a K&N lid. Might be an improvement if the carb doesn't like the drop base putting a restriction close to it with the solid lid. Will also try different idle mixes, hopefully I will find my vac gauge.

This 4966 doesn't feel as crisp as the other one I tried that had the boogered up stuff. It had the one off size rod, makes me think this one could use some tuning but it is hard to go off a cobble carb as a guide. It seemed to really jump on throttle movement more than this 4966 does.

Thanks for all the help!

I checked the WOT when a helper arrived and found that I can't get it any closer. It is about 1/16th off. Not the end of the world.

I got out the K&N lid and found out that I had to run a K&N main filter because they made it so it won't fit down in a stocker. I wanted to run ONLY the lid to see if that made any difference.

The engine then idled roughly and was at only about 650 RPM, not the 850 or so it had held steady before. I had to turn the speed screw up, but wrote that off on something to do with messing around with the throttle cable. Doesn't make any sense, but that is all i came up with on that.

The drive showed a worse running engine, so i returned home to reinstall the old lid and paper filter. No dice, the car now runs crappy. I dorve around with the "good" setup awhile and concluded that it runs like it did before the accel pump fixes today.

So, the air is cooler tonight. Like last night. When it ran good today, the water temp was 170-180. Tonight it ran 160-170. Maybe the more dense air makes it too lean???