I also just had a 57 bird come in with one of these 1848 carbs on it and am going through it now, question? how much should the secondary blades be open? and it is also missing 2 screws in the base and I checked another one laying around and it also is missing the same 2 screws, did they normaally come without those?

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

The Slotted Screws are from my old Teapot. This Carb was missing 2 and the Teapot Ones are same TPI and just a little shorter. If this was someones Handiwork why not put it back together as it wont work with this Base? Complete waste of a new Carb by not doing so.The Linkage on the other Side is the same as what comes on the 8007 390. I trimmed off part of the Linkage using a Dremel to use the Rod and retaining Clip  type on my Ford. The correct 1848-1 Base has a Triangle shape Lever which apparently is designed to use on a Ford.

  

Based on the pictures you provided, this doesn’t look like a Holley blunder with the slotted screws that are in place.  While it’s possible someone was trying to make this carb have a vacuum port, it’s more likely that the original base plate went on a different carb so that the Ford linkage would be more compatible on that other carb.  You don’t show the linkage side of your particular carb but that might help to shed some more light on what you have and why it ended up this way.

Lorena, Texas (South of Waco)

Yeah but at least now I know why it would not work properly. I still think this was assembled wrong at Holley. Why would anyone swap the base on a brand new Carb?.
Nothing to be gained. Throttle bores are the same Size. Who knows?. 

  

Ahhh bugger!



"Came too close to dying to stop living now!"

Those 2 Slot Head were my doing. Missing when I got it.

  

Looks like someone butcher together this one, I doubt Holley assembled it with a few slot head screws..

Finally figured out whats wrong with this Carb. I contacted a Rebuilder and sent some Pictures. He knew right away what the Problem is. This 1848 Carb has a 600 CFM Base Plate on it. Either someone messed with it or it was assembled wrong from the start. My Opinion is it was assembled wrong at Holley. It does not look like it was tampered with. Have a look at the Pictures and look at one on Ebay. The 1848 has no PCV Port and only One vacuum Source for Distributor. The Base on mine has PCV and 2 Vacuum Ports. It will never work with mismatched Base and Body.  Frankenstein Carb. Anyone need a like new 1848-1 Carb for Parts or put the proper Base Plate on a like new Carb?

  

Thanks Ted. I actually thought of that too. Bought a can of spray Carb Cleaner and removed Idle Screws. Sprayed cleaner down the Vent Holes using the included "Straw" and a steady Stream of Cleaner came out where the Screws go. Still working on it. 

  

While this may or may not be obvious, you might double check that the bowl vent tubes are clear.  On most Holley 4V carbs, those vents are located on the main body and not on the bowls.  The most common cause for the vent tube(s) to be plugged would be a mud dauber plugging them.

Lorena, Texas (South of Waco)