• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

AVS Carter Carb

QOTHL

QOTHL

Well-Known Member
Local time
9:17 PM
Joined
Sep 13, 2017
Messages
7,081
Reaction score
8,256
Location
Planet Mopar
I had the original carburetor sent out for restoration. I've had them done before and no problems once they were adjusted properly.

The one on my 69 Charger R/T SE has been adjusted several times and I'm making this as simple as possible because we've had other problems with the rebuild. A really good Mopar carb guy with a lot of experience adjusted it last year- correction, 2018, and it ran perfect for the rest of the season. The following year, I started having problems with low idle after warming it up and driving it where it would stall at lights, trying to park, back up, etc.
If anyone has any suggestions, please let me know if it's just a simple matter of adjusting the idle. I'm no expert and would appreciate any advice.
 
Last edited:
QOTHL said:
I had the original carburetor sent out for restoration. I've had them done before and no problems once they were adjusted properly.

The one on my 69 Charger R/T SE has been adjusted several times and I'm making this as simple as possible because we've had other problems with the rebuild. A really good Mopar carb guy with a lot of experience adjusted it last year and it ran perfect for the rest of the season. The following year, I started having problems with low idle after warming it up and driving it where it would stall at lights, trying to park, back up, etc.
If anyone has any suggestions, please let me know if it's just a simple matter of adjusting the idle. I'm no expert and would appreciate any advice.
Click to expand...

I'm assuming that your engine is the 440, but is it automatic or 4 speed and does it have A/C. There are subtle differences between auto trans and 4 speed applications and in addition, A/C car's carbs had a hot idle compensator device.
Vacuum leaks usually manifest themselves as erratic idle and off idle transition. YES, it may be as simple as readjusting the idle speed and tweeking the mixture screws slightly. Make sure the carb mounting bolts sre tight. Today's fuels are also problematic and sometimes cause the issues you note.
The original Carter AVS carb is an excellent performer....others will say replace it with an Edlebrock (aka "Eddy") performer model or fuel injection. But in the interest of originality, keep the Carter carb.
Since the origional carb was a product of the emission requirements of the day, there are a few "fixes" to correct off idle transition circuit lean conditions. Do not be afraid to experiment a little with your carb...its to your advantage. I'm sure others will recommend using a vacuum gauge to set the carb, I've always used RPM readings. Also check the badic timing to eliminate that variable. Just my opinion of course.
BOB RENTON
 
Dirty gas, maybe a few pieces of crap in carb. Miles since '18? Might be time for overhaul?
 
Check the nuts on the carb base.
Also try turning up the idle speed just a bit.
Maybe the idle speed adjustment just backed off a little.
 
Should be no more than 2 turns. 1.5-2.0 is the norm. Don’t crank them in. They just need to be lightly seated then backed out. Kim
 
In addition to the previously mentioned check points, some models of the Carter AVS carb had a SINGLE idle mixture screw, which was an adjustable AIR bleed screw controlling the idle mixture, which was turned in to richen the mixture, by reducing the air flow to the mixture. The "real" idle mixture screws were hidden behind 2 small lead plugs near the mounting flange. These plugs were easy to remove and with a small screwdriver, the hidden screws re-adjusted to provide a smooth idle. In addition, there is a "hidden" off idle transition circuit adjustment screw, which can be turned to richen the off idle mixture, which helps to reduce or eliminate a stumble, not related to the accelerator pump circuit or rate of advance and initial timing setting. Carter carbs are easy to work on and understand the various systems functions. Just my opinion of course.
BOB RENTON
 
The reason I asked about the idle screws is, that era AVS carbs were generally lean, and sometimes the idle screws can’t get them rich enough. Internal modifications must be made.
 
Woodruff Carbs said:
The reason I asked about the idle screws is, that era AVS carbs were generally lean, and sometimes the idle screws can’t get them rich enough. Internal modifications must be made.
Click to expand...

Absolutely true....usually these internal mods to the idle feed restrictions (source of all idle and idle transfer fuel) are located in each of the primary booster vsnturii assembly. One must be cautious when enlarging these restrictions (they are decimal number drill sizes) as they are vary small diameter and if drilled too big, are very difficult to return to the origional size. Just thinking out loud....
BOB RENTON
 
First things first: check the idle speed, initial timing, and then the idle mix...
 
RJRENTON said:
I'm assuming that your engine is the 440, but is it automatic or 4 speed and does it have A/C. There are subtle differences between auto trans and 4 speed applications and in addition, A/C car's carbs had a hot idle compensator device.
Vacuum leaks usually manifest themselves as erratic idle and off idle transition. YES, it may be as simple as readjusting the idle speed and tweeking the mixture screws slightly. Make sure the carb mounting bolts sre tight. Today's fuels are also problematic and sometimes cause the issues you note.
The original Carter AVS carb is an excellent performer....others will say replace it with an Edlebrock (aka "Eddy") performer model or fuel injection. But in the interest of originality, keep the Carter carb.
Since the origional carb was a product of the emission requirements of the day, there are a few "fixes" to correct off idle transition circuit lean conditions. Do not be afraid to experiment a little with your carb...its to your advantage. I'm sure others will recommend using a vacuum gauge to set the carb, I've always used RPM readings. Also check the badic timing to eliminate that variable. Just my opinion of course.
BOB RENTON
Click to expand...


Sorry, I didn't get a notification that you posted a reply. Yes, 440 original everything including the Carter, it even has the tag from the manufacturer. It has been restored and rebuilt. It is an AC car. I've checked the bolts and really couldn't get more turns, hardly anything and I didn't want to wail on them.
NO I won't be replacing it. I know it is just some simple matter of figuring it out. We used RPMs and the guy who really had it running near perfect just did it by ear. He's a big Mopar guy and used to race dirt bikes and has a lot of experience with carbs. I've mentioned this problem to him, we're just waiting for better weather to deal with it but in the mean time I figured I'd ask this forum. Thanks for the advice! I don't believe in bailing out on original stuff especially on a car like this.

I forgot to mention that this car has the biggest cam possible without changing the stock stall converter.
 
RJRENTON said:
In addition to the previously mentioned check points, some models of the Carter AVS carb had a SINGLE idle mixture screw, which was an adjustable AIR bleed screw controlling the idle mixture, which was turned in to richen the mixture, by reducing the air flow to the mixture. The "real" idle mixture screws were hidden behind 2 small lead plugs near the mounting flange. These plugs were easy to remove and with a small screwdriver, the hidden screws re-adjusted to provide a smooth idle. In addition, there is a "hidden" off idle transition circuit adjustment screw, which can be turned to richen the off idle mixture, which helps to reduce or eliminate a stumble, not related to the accelerator pump circuit or rate of advance and initial timing setting. Carter carbs are easy to work on and understand the various systems functions. Just my opinion of course.
BOB RENTON
Click to expand...

The R/T SE carb has two screws, the other Charger Carter has the single screw. Someone told me that single screw carb could not possibly be original on a 69...?
 
What model # is your carb,n just for reference the SE option has nothing to do with the model of carb as they were different to weather they were autos,manual trans or equipped with A/C
 
CHARGERSTEVEN said:
What model # is your carb,n just for reference the SE option has nothing to do with the model of carb as they were different to weather they were autos,manual trans or equipped with A/C
Click to expand...
The major carb difference between cars with auto trans and std trans are primary booster venturii as ALL idle and off idle fuel originates in the boosters. In addition, the metering rods are different size in the down position. The metering rods and jets control the fuel delivery when the boosters are feeding fuel; but idle fuel originates in the boosters thru fixed fuel and air restrictions and of course the mixture screws. Carbs used with A/C equipped cars have a thermostatic controlled air bleed to elevate an over rich mixture due to hot under hood temps.
I've seen both 69 & 68 models with the single idle mixture screw. This is about the same time as the "off idle air bleed" appeared to elevate a leaner off idle transition due to increasing emission requirements, in addition to altered distributor advance characteristics. Sometimes, a dashpot (manual trans) or a anti-diesel solenoid was also included...on '69 - '70 + models. Not sure that answered your questions.
BOB RENTON
 
RJRENTON said:
The major carb difference between cars with auto trans and std trans are primary booster venturii as ALL idle and off idle fuel originates in the boosters. In addition, the metering rods are different size in the down position. The metering rods and jets control the fuel delivery when the boosters are feeding fuel; but idle fuel originates in the boosters thru fixed fuel and air restrictions and of course the mixture screws. Carbs used with A/C equipped cars have a thermostatic controlled air bleed to elevate an over rich mixture due to hot under hood temps.
I've seen both 69 & 68 models with the single idle mixture screw. This is about the same time as the "off idle air bleed" appeared to elevate a leaner off idle transition due to increasing emission requirements, in addition to altered distributor advance characteristics. Sometimes, a dashpot (manual trans) or a anti-diesel solenoid was also included...on '69 - '70 + models. Not sure that answered your questions.
BOB RENTON
Click to expand...
I understand the difference in the carbs,just wondering if op had the rite model on his car as he said it was all original.Just though maybe someone some time change it
 
CHARGERSTEVEN said:
What model # is your carb,n just for reference the SE option has nothing to do with the model of carb as they were different to weather they were autos,manual trans or equipped with A/C
Click to expand...


Not sure if this is directed at me but the tag says, and it matches the carb, 4640 SA. There is another number 0859 and then a large 92. I believe this is the right carb for an AC car.
 
You must log in or register to reply here.

Similar threads

Tony 70GTX
Carter AVS 4737S 1970 GTX 440 4BBL
2 3
Replies
40
Views
3K
Some Car Guy
S
Tony 70GTX
Carter AVS 4737 4BBL 1970 440 GTX
Replies
10
Views
1K
RJRENTON
RJRENTON
pdiz
Carter AVS 6125S model applications
Replies
10
Views
491
pdiz
pdiz
AR67GTX
Carter AVS question?
Replies
8
Views
950
AR67GTX
AR67GTX
G
Carburetor running rich after rebuild
2 3 4
Replies
67
Views
5K
JC Boatguy
JC Boatguy
Auto Transport Service
Back
Top