Carter AVS questions

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markfh

markfh

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I have a 68 Dart GTS 340. I'm rebuilding the carburetor and my Carter AVS 4425S isn't exactly like those I see on the Internet. All the ones I see on the Internet have two idle adjustment screws but mine only has one as you can see in the images. The holes where it appears there should be two are plugged. Any idea why and is it unusual?

Also, any idea what the H7 means? Is that the month and year of manufacture?

carb 1.jpg


carb 2.jpg
 
That upper center knob is an air bleed to trim the carb a bit further. Handy if you want to super tune that carb for better operation over the standard carb.
 
I believe H7 means August of 67. The guys with the real knowledge will chime in I’m sure.

Jake
markfh said:
I have a 68 Dart GTS 340. I'm rebuilding the carburetor and my Carter AVS 4425S isn't exactly like those I see on the Internet. All the ones I see on the Internet have two idle adjustment screws but mine only has one as you can see in the images. The holes where it appears there should be two are plugged. Any idea why and is it unusual?

Also, any idea what the H7 means? Is that the month and year of manufacture?

View attachment 1715395517

View attachment 1715395518
Click to expand...
 
markfh said:
I have a 68 Dart GTS 340. I'm rebuilding the carburetor and my Carter AVS 4425S isn't exactly like those I see on the Internet. All the ones I see on the Internet have two idle adjustment screws but mine only has one as you can see in the images. The holes where it appears there should be two are plugged. Any idea why and is it unusual?

Also, any idea what the H7 means? Is that the month and year of manufacture?

View attachment 1715395517

View attachment 1715395518
Click to expand...
What Rumblefish said is correct.
The '68 Plymouth FSM covers the carb pretty well. The Dodge manual probably does too.
This MTSC covers some of the unique features for carbs that year.
1968 Chrysler Carburetor Service Highlights Service Book - Session 243

One thing to keep in mind is by controlling the idle air bleed, only very fine adjustments can be made.
The objective was to keep these cars idling at a relatively lean mixture (for idle).

1968 Engine Performance Diagnosis (Session 250), Master Technician's Service Conference
 
Whoaaaa, nice link BRO! I never knew that existed. Cooooooooolllllllll

I had one for a spell. Nice carb. Once I realized what it did, I played with that thing like crazy. Drive me crazy a few times! LOL But, that was the finest running carb I had. Super sweet.
 
markfh said:
I have a 68 Dart GTS 340. I'm rebuilding the carburetor and my Carter AVS 4425S isn't exactly like those I see on the Internet. All the ones I see on the Internet have two idle adjustment screws but mine only has one as you can see in the images. The holes where it appears there should be two are plugged. Any idea why and is it unusual?

Also, any idea what the H7 means? Is that the month and year of manufacture?

View attachment 1715395517

View attachment 1715395518
Click to expand...
Sorry about the hijack ,just curious, is your car an automatic and is that the original carb? My 69 340 has the original carb A9 4611SA and is a 4 speed. I had a discussion with someone who has a 4611S and he said that was the 4 speed carb. Not sure what the A stands for.
 
markfh said:
I have a 68 Dart GTS 340. I'm rebuilding the carburetor and my Carter AVS 4425S isn't exactly like those I see on the Internet. All the ones I see on the Internet have two idle adjustment screws but mine only has one as you can see in the images. The holes where it appears there should be two are plugged. Any idea why and is it unusual?

Also, any idea what the H7 means? Is that the month and year of manufacture?

View attachment 1715395517

View attachment 1715395518
Click to expand...
the two holes below the two plugged holes seem to be missing something

overview.jpg
 
A56 said:
the two holes below the two plugged holes seem to be missing something

View attachment 1715395814
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Thats a different model AVS for a different application...there's nothing missing on the single screw AVS waaayyy up there^^^^^^. You'll probably find little grub screws/mixture screws buried in those wee holes. Each different model number denotes changes in the carbs design or calibration for different years or engines.
 
A56 said:
Sorry about the hijack ,just curious, is your car an automatic and is that the original carb? My 69 340 has the original carb A9 4611SA and is a 4 speed. I had a discussion with someone who has a 4611S and he said that was the 4 speed carb. Not sure what the A stands for.
Click to expand...
No problem. Yes, it's an automatic and it is the original carb. At least I've had the car since 85 and I'm the 3rd owner and know the history of the car back to the first owner.
 
65Val said:
Thats a different model AVS for a different application...there's nothing missing on the single screw AVS waaayyy up there^^^^^^. You'll probably find little grub screws/mixture screws buried in those wee holes. Each different model number denotes changes in the carbs design or calibration for different years or engines.
Click to expand...

Yep, there are little grub screws buried in there.
 
Thanks for all the responses and the info. As I continue to work on this car I'll have more questions. I'm sure.
 
Okay rebuilt and seems the accelerator pump isn't pumping. I warmed up the engine and shut it down. When I manually actuate the linkage I see no jet of gas in the primaries. Is that the check valve under the pump?
 
There is a check valve under the cluster. Depending on the year of the carb, it can be a shinny steel ball or a brass rectangle.

Not trying to be a jerk but you did install a new plunger right? And of course the rod with it.
 
rumblefish360 said:
There is a check valve under the cluster. Depending on the year of the carb, it can be a shinny steel ball or a brass rectangle.

Not trying to be a jerk but you did install a new plunger right? And of course the rod with it.
Click to expand...

Yep. Replaced everything that came in the rebuild kit.

This one doesn't have the steel ball and I think I remember the brass rectangle. I'll open it up again and check.
Thanks
 
A56 said:
Sorry about the hijack ,just curious, is your car an automatic and is that the original carb? My 69 340 has the original carb A9 4611SA and is a 4 speed. I had a discussion with someone who has a 4611S and he said that was the 4 speed carb. Not sure what the A stands for.
Click to expand...
The A9 should be January 1969 built.
 
Found this document about rebuilding the AVS and my AVS didn't have the little discharge check needle shown in the image attached when I rebuilt it. Is this something I need or what?

Carter AVS discharge check needle.jpg
 
markfh said:
Found this document about rebuilding the AVS and my AVS didn't have the little discharge check needle shown in the image attached when I rebuilt it. Is this something I need or what?

View attachment 1715411938
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Every AVS/AFB I've rebuilt had one of those, or similar. I believe it blocks the passage that allows the accel pump well to suck fuel from the bowl, and not from the squirters.
 
65Val said:
Every AVS/AFB I've rebuilt had one of those, or similar. I believe it blocks the passage that allows the accel pump well to suck fuel from the bowl, and not from the squirters.
Click to expand...

Oki doki. I'll order some since all I can find is a package of them. Need a power booster check valve seal as well.


Thanks
 
65Val said:
Every AVS/AFB I've rebuilt had one of those, or similar. I believe it blocks the passage that allows the accel pump well to suck fuel from the bowl, and not from the squirters.
Click to expand...

One more question. Do you know what size that needle is? Seems there's more than one.
 
The needle as the check valve or the needle and seat needle?
 
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