Carter rebuild reference help

[alini]

**edit...I found the numbers in the service manual, so I do have the correct parts in the car....now to order replacements

 

 

 

So the car runs, but I cant get it to idle.  I have issues with the throttle, if I let off it to a normal idle adjustment it dies.  When I rebuilt the carb I just took it apart and reassembled it with new gaskets and accelerator pump.

 

Im digging in now, and found both metering pins are bent and based of the service manual and two manuals I downloaded from the internet, I am missing the accelerator discharge check valve.

 

I want to confirm the metering pins and jet sizes I have.  Im running a 3921S carter AFB, this number doesnt seem to show up on any online sources but I have seen numerous threads about them and they are correct for a 65.

 

I have metering pins 16-219, primary jet 120-256 and secondary jets 120-158.  Does anyone have a manual to confirm these are adequate numbers for a factory 401.   I will order replacements but dont want to order them if they arent the correct size to begin with.

Edited March 15, 2016 by alini (see edit history)

[alini]

I also found the accelerator pump check valve is bad and I found my seats (for the float needles) were 'leaking' so the float level didnt matter fuel was getting in the bowls. 

[alini]

Anyone got a good source for carb parts, so far my searches are turning up nothing.   Sadly the rod size is .068 x .062 and it appears no one makes those anymore.

[Bill Stoneberg]

CarbKing frequents these forums and is a BIG help in most things carb related.

 

Check out his web site and give him a call

 

http://www.thecarburetorshop.com

[carbking]

The 3921 number DOES show up on-line: 

 

http://www.thecarburetorshop.com/Kbuick3.htm

 

If you were looking for 3921s, that probably does not show up. The "S" in Carter terminology, means "assembly", and is normally not included with carburetors numbers in most lists:

 

http://www.thecarburetorshop.com/Carburetor_ID.htm

 

The pump inlet check valve is in the better repair kits.

 

ALL sizes of step-up rods and metering rods for ALL Carter carburetors are available; however, as they are custom-made, they are not inexpensive.

 

Step-up rods which are bent in the center of the rod may be straightened. Step-up rods which are bent in the bottom 1/2 inch (the metering section) normally are not savable, but it certainly doesn't hurt to try. Most rods bent in this area are because a previous "rebuilder" attempted to place the airhorn on the bowl with the rods attached. The LAST items installed on any Carter AFB are the step-up rods followed by the step-up rod covers.

 

Jon.

Edited March 15, 2016 by carbking (see edit history)

[60FlatTop]

As I scrolled through this post I was thinking, just straighten them, like Jon. The last time I rebuilt my '64 AFB I had the original carb and an old 1959 Lincoln AFB for parts; and all the pieces in a pile on the bench, what went back in were just what I liked the looks of.

I used one of Jon's kits when I rebuilt the dried old carb for my Packard a couple of years ago. He probably wouldn't have liked witnessing what I did but it runs good.

 

A old carburetor engineer who was a friend of Ed Cole and learned on 4GC's, then helped design the Quadrajet. (He's the guy who put the long screws in the venturi) told me carburation is not engineering, it's art. Fuel injection is engineering. A carburetor is just a pot of gasoline on top of your engine subject to air pressure differentials. It's not very accurate or predictable off the drawing board or in application. So be prepared to fiddle with it a little on your car to get it right. For all it's little pieces it is a low tech device. If you get 15 MPG and drive 60 MPH that's four gallons of gas spitting through those little holes in an hour, 15 minutes to drain a gallon can into your engine. That's why we have FI now.

 

My point is to lighten up and do it with a flair. Tap the rods with a 4 oz. hammer, be willing to take it apart a few times, and massage it. You know, I heard Colin Powell enjoys carburetor work; and he takes a general approach as well.

Bernie