Rebuilding an AVS and wondering about mods.

[375instroke]

I have a '69 AVS, 4618S, and am wondering about a few things.  This plug is supposed to cover an off idle adjustment screw, according to the FSM.  Should I gain access to it for cleaning and adjustment?



There is a spring inside that presses against a ball bearing, and on the top, it opens to the atmosphere.



It allows extra air to enter after the idle mixture screw, which itself just adjusts how much the idle fuel is diluted.



This is where the air comes from that goes through the idle mixture screw, and into the idle circuit.



This is where the idle limiter screws, as the FSM calls them, are located.  They are covered by a plug and staked in.  Should I gain access to them for the rebuild also?



Finally, there is this thermostatic air bleed, which I thought was only on A/C equipped cars, like the 4640S carb.  It looks like it opens to a blind hole.  I don't see any holes inside.  Wonder why they wouldn't eliminate it on carbs that aren't drilled for it.





Why are the Edelbrock mixture screws up on the diagonal part, and the Carter has the same plugs next to the PCV port, and their mixture screws are below those?

[resq302]

The AVS are very limited to mods which is why a lot of people prefer the Holleys over them.  It appears that you have an early model carb as the later ones had SA after the carb number.  The A was a designation for a factory revision, in this case, the A on my 4615SA carb for my 69 charger with a 383 4 bbl, the single left hand threaded mixture screw is plugged and the two lower mixture screws are in place where your two plugs are.  Really the only adjustments that are available for the AVS is to change out the metering rods and jets for primary and secondaries.  Even then finding strip kits for the AVS carbs are hard to do.  A lot of people end up changing out the vacuum piston, metal retainer cap, jets and metering rods to the AFB parts which can interchange but you have to do all of the parts and not just some.  The AVS carb is a 2 step system vs. the AFB carb which is a 3 step system. 

Hope this helps.

[Ghoste]

Actually the AVS is the one with the three step rods (that's why they have the dimpled covers).

[resq302]

Ghoste,  you're correct.  Momentary lapse of memory with everything that is going on in the home front lately.

[375instroke]

My Charger has a September '68 build date, and I found a September '68 carb, so that explains the early design.  I'm not looking for major mods.  I'm just wondering about gaining access to the adjustments I mentioned.  I've seen pictures of carbs like mine with the lead plugs removed from the idle limiters.  There are tiny screws in there, and I have no idea what holds them from turning, like is there an interference fit on the threads that allows them to maintain their adjustment?  Is there any problem with leaving the plugs off?

[Ghoste]

I was pretty sure you knew that Brian and that it was just a late night typo but I figured it was important enough to interfere.

[resq302]

I was pretty sure you knew that Brian and that it was just a late night typo but I figured it was important enough to interfere.

No you were correct to notate the correction.  Lack of sleep, working late night shifts, and some issues at home all lead to the memory not being as sharp as what it has been.  Aw hell, who am I kidding, my memory has not been that great from the start.   

[375instroke]

I fixed the pics I messed up on showing the thermostatic valve.

[375instroke]

Here are some more pics.  This is the port where the A/C equipped cars have that thermostatic air bleed that was on this carb, but the port wasn't drilled.





Here's the bottom:



I started with this:



I removed the plugs with these tools, turning by hand, and this is what came out:



I wish someone told me that the threads go all the way to the front of the carb.  I thought the idle screws were smaller than the normal ones, and people tapped the holes for the bigger adjusters.  Well, I didn't damage the threads, so all is good.  I'll use the adjusters from the Edelbrock if they fit instead of the small ones.



As for that off idle adjuster--if I have problems, I'll just plug the hole.

[Just 6T9 CHGR]

Very cool...watching this one.
How deep into "restoration" are you going with this carb?  Will you replate all the linkages etc?

[375instroke]

No replating.  I'm already taking forever with this.  The motor's not rebuilt, or restored, and someone did a bit of a rattle can rebuild, so I'll just clean it and get it working.