'66 Newport Carburetor

[5fty7vn]

I'm wondering if anyone could give me some advice. My '66 Newport is running pretty rich. The carb was rebuilt about 11-12 years ago and when I go to start the engine while it's cold it'll almost always start for a second before it dies out.......as if there is unspent fuel igniting. When I go to start it after it's been running I have trouble getting it started.............although it's never not started on my. I took some pictures of the carb with a cold engine and after it's hot.......I didn't notice anything stand out between the two. The questions I have are:

in photo 1, the grommet marked "A" stayed open while the engine was cold and hot, not sure if it's supposed close at some point or not.............

in photo 2, the rod marked "B" has some play in it so i'm not sure if that's a problem or not.....of if there is a spring or something underneath the cover at the bottom of the rod (seen with the two bolts)

in photo 3, the "pin" marked "C" isn't connected or tied to anything so I have no clue what it's purpose is............the curved rod marked "D" isn't connected to anything either, other than the vacuum it's running to. It just slides along the groove (the end with the clip on it) and I have no clue what it's purpose is either..........

Any help would be appreciated.............

 

[440Sled]

The rod that goes in to the intake manifold is your choke. When the engine is cold it's supposed to close the flap over the primaries for a cold start. When the engine heats up, it opens. there is a coil spring that controls all of that. I forget what photo "A" is, sorry, but from the looks of it, it looks like it leaks a lot of fuel and needs a rebuild.

 

[moper]

12 years ago it was rebuilt? You know it was common when these were on the road to do them every 20-30K miles. Looking at it I'd rebuild it and clear all the little passages with carb clean or shop air.
"A" is the bowl vent. as the throttle opens that part closes.
"B" is the rod that connects the choke stove to the carb choke plate.
"C" - No clue what that is. Don't recall ever seeing one before.
"D" is the rod that connects the choke pull off to the choke plate.
When it's cold, "B" rod is pushed up by the choke spring. That pushes the choke plate closed so the engine can start easier, it also moves the high idle cam into place on the throttle side of the carb.
Once the engine starts the "C" rod pulls back and if you were to need it more air as it's warming up, the pull off would overcome the choke and open the choke plate as you drive. It also pulls the choke plate open as the choke coil at the base of rod "B" heats up and the rod is pulled down, opening the choke plate.

 

[5fty7vn]

12 years ago it was rebuilt? You know it was common when these were on the road to do them every 20-30K miles. Looking at it I'd rebuild it and clear all the little passages with carb clean or shop air.
"A" is the bowl vent. as the throttle opens that part closes.
"B" is the rod that connects the choke stove to the carb choke plate.
"C" - No clue what that is. Don't recall ever seeing one before.
"D" is the rod that connects the choke pull off to the choke plate.
When it's cold, "B" rod is pushed up by the choke spring. That pushes the choke plate closed so the engine can start easier, it also moves the high idle cam into place on the throttle side of the carb.
Once the engine starts the "C" rod pulls back and if you were to need it more air as it's warming up, the pull off would overcome the choke and open the choke plate as you drive. It also pulls the choke plate open as the choke coil at the base of rod "B" heats up and the rod is pulled down, opening the choke plate.

It's had about 5K miles on it in the past 10 years...............the "D" rod just slides back and forth in that groove but doesn't move that bracket at all..........

 

[Knebel]

I could tell you something to the hot/cold start sympthom. When the engine is cold and you go to start it, it starts but quickly dies and after that starts fine, the choke or choke pulloffis misadjusted. Specifically too lean.

The hot start issue...hm, it could be that the choke dosent open all the way or you simply need to adjust the idle mixture. My holley idles on the rich side too and now that it gets really hot here it needs longer cranking to start...sooo...idk

 

[1970cat]

check the vacuum on the pull off with a vacuum pump. the pull off puts pressure on the choke plate to pull it open as the choke stove warms up and lessens the tension on the choke plate. not sure of the exact dimensions on your carb but when cold the choke plate should be shut solidly(not loose) with about 5/16" gap between the choke plate and the front of the air horn

 

[moper]

It's had about 5K miles on it in the past 10 years...............the "D" rod just slides back and forth in that groove but doesn't move that bracket at all..........

Mielage doesn't matter. If you're not driving it you should still rebuild it if you want to. Think of the changes in the last 5 years in regard to fuel chemistry...
The bracket for "D" doesn't do anything unless the choke is on. When the choke plate is closed then that rod should have a little freeplay, which is taken up when the engine starts and the dashpot retracts the arm.