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Old 09-18-2023, 01:08 AM
69400 69400 is offline
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Default Carter 4852S service replacement

I was wondering if anyone knows the original calibration of this carburetor (jets, rods, main air bleeds, etc). Only info I have is that it's a 7029262 replacement.
Just bought it off eBay it looks complete but wanted to double check that it wasn't modified at all thank you.

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Old 09-18-2023, 12:16 PM
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Try Jon Hargrove at The Carburetor Shop. He doesn't do emails I don't think but he's active at this site and he takes phone calls.
You may be able to find the answer just exploring his web store. Lots of info there..
https://www.thecarburetorshop.com/

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Old 09-19-2023, 03:25 PM
rockys1970 rockys1970 is offline
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You will need to clarify what carb you need info for.

Your title mentions a Carter # but the Part # you mention, 7029262 is a 1969 Rochester Quadrajet. I can help if its a Q-Jet. I will need to know the application, and the engine size.

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Old 09-19-2023, 03:40 PM
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It is indeed a quadrajet, but with a Carter part # because Carter made aftermarket service replacements using their numbers. Application for a 69 428, big car.

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Old 09-19-2023, 03:44 PM
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Carter 4852S is an aftermarket replacement Quadrajet for 1969 Pontiac V8īs.
Those usually havs a couple of #īs larger main jets and primary rods, otherwise mimics the 7029262 regarding idle and main airbleeds
F.e. the Carter 4887S Quadrajet from the same series have #74 main jets and #46 primary rods.

HTH

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  #6  
Old 09-19-2023, 04:50 PM
rockys1970 rockys1970 is offline
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Default Rochester 7029262

From my factory Delco Rochester Parts Manual.
Hope this helps. I tried scanning to a pdf but the file was to large to post.
Primary Jets 72
Primary Rods 45

rockys1970
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Old 09-19-2023, 05:16 PM
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Thanks guys, was trying to find a good baseline Since it's going on a mild cammed (Crower 60242) YS code 400.

Idle system was modified but the air bleeds weren't. Opened it up and had .038 idle tubes and .052 DCR with a .050 upper idle bleed and .070 lower idle bleed and .110 bypass. Jets were a 71/41 with a .070 main.

Suppose I'll try a 73/43 with a BE Secondary as a baseline when I rebuild it. If idle is too rich I have the screw in the air horn for idle air.


Last edited by 69400; 09-19-2023 at 05:25 PM.
  #8  
Old 09-20-2023, 02:35 AM
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Sounds like a good plan.
Can you post pictures on the carb/air horn?

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  #9  
Old 09-20-2023, 11:28 AM
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Ram Air IV Jack Ram Air IV Jack is offline
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Quote:
Originally Posted by 69400 View Post
Thanks guys, was trying to find a good baseline Since it's going on a mild cammed (Crower 60242) YS code 400.

Idle system was modified but the air bleeds weren't. Opened it up and had .038 idle tubes and .052 DCR with a .050 upper idle bleed and .070 lower idle bleed and .110 bypass. Jets were a 71/41 with a .070 main.

Suppose I'll try a 73/43 with a BE Secondary as a baseline when I rebuild it. If idle is too rich I have the screw in the air horn for idle air.
Call Cliff Ruggles!! Cliff knows these carbs inside and out and I'm sure he could help you and explain what is and is not correct on that carb. Cliff will also need to know what you want out of this carb and the engine parameters the carb is going on!!!

https://cliffshighperformance.com/

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Old 09-20-2023, 12:49 PM
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Quote:
Originally Posted by 69400 View Post
Thanks guys, was trying to find a good baseline Since it's going on a mild cammed (Crower 60242) YS code 400.

Idle system was modified but the air bleeds weren't. Opened it up and had .038 idle tubes and .052 DCR with a .050 upper idle bleed and .070 lower idle bleed and .110 bypass. Jets were a 71/41 with a .070 main.

Suppose I'll try a 73/43 with a BE Secondary as a baseline when I rebuild it. If idle is too rich I have the screw in the air horn for idle air.
I'm running that same cam in my '68 YS 400. I'm using a 1974 carb. I rebuilt it using Cliff Ruggles' recommended changes for a mild performance upgrade (recipe #2) and the it's is just about dead on what you listed above. It's been running trouble free for years. No hesitation, no bog.

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Last edited by Greg Reid; 09-20-2023 at 12:57 PM.
  #11  
Old 09-20-2023, 03:21 PM
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@kenth I have no pictures but the air horn looks like any other '69-70 with the primary POE and the 4 brass tubes under it, as well as the idle vent valve on the front. The body has the "updated" smaller float and a hot idle compensator that was plugged with a piece of lead.

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