Rochester 2g year id

I did a search but couldn't find what I was looking for.

I have these two Rochesters. The left one is configured differently (the way the choke is closed/opened) on the top piece than the right one. Both have been rebuilt, but the left one (from a donor jeep) makes my :v6: run much better than the right one (original Jalopy piece). Why could that be? and what year is each of the carbs from? I can get the engine numbers if that will help.



After rebuild. All clean!

 

You can get the year right off of the carb. If it's starts with 704 then it was built in the 70's and the next number will be the year. If it starts with 702 then it was built in the 60's.

 

There's a slight problem with that, the left one has no numbers. To get my rebuild kit, I used the numbers off the other one.

 

It's hard to tell from the pics but the cleaner carb looks like it was origionally an auto choke set up converted to manual.
The other looks like it started out as a manual choke carb.
As long as they both have the plumbing for PCV, etc. I'd use the one that works best for now, unless there's some other issues.
As far as 1 working better, can be several things, main jet(s) size, worn throttle shaft,crud still somewhere internal in a passage ,vacumn leak.etc..
Hard to tell from here.

 

From the pics it appears these are both Rochester 2 Jets.
Jeep used 6 versions of this carburetor on the Dauntless 225.
Four of them are model 2 G. The other two are model 2 GC.
Left is a model 2 G the right is a model 2 GC.
These pics do not exclude non Jeep applications and we know not if component interchange has occurred.
Identifying the engine via number can be helpfull but it cannot gaurantee posative identification.

According to Jon Hardgrove: http://www.thecarburetorshop.com/Carburetor_ID.htm#IDservice

2G Series (2G, 2GC, 2GV) – (1955 - 1967) (2 barrel) triangular metal tag
2G Series (2G, 2GC, 2GV) – (1968 – up) (2 barrel) roll stamp on side of bowl

Roll stamps: Beginning in 1968, all Rochester carburetors were "roll stamped" with the identification number on the side of the bowl.
These are "stamped" or "recessed" numbers, not "raised" as discussed below

Casting (raised) numbers: Raised numbers appearing on various castings are so-called "casting" numbers.
These numbers were used by Rochester to identify a casting "blank" PRIOR to machining.
A casting could be machined into different parts.
IT IS IMPOSSIBLE TO IDENTIFY ROCHESTER CARBURETORS FROM CASTING NUMBERS ALONE!

I generally agree with the above. Here's my identification suggestion:

1) Indicate any numbers found upon the fuel well body.
Found under the fuel inlet fitting as a stamp or found on the side of the fuel well body as a raised casting number.
2) Locate the raised casting number for the air horn body....It is located internally under neath the float.
3) Note the size of the main venturi....This is raised number found internally just above the venturi.
4) Locate the number upon the metering cluster....This is an internal part suspending the boost venturi.
5) Note the size of the main metering jets 47 48 49 50 51 or 52
6) Measure the diameter of the throttle bore....It is located within the cast iron mounting flange.
7) Designate engine serial number

 

Thanks!

No wonder why I couldn't find the numbers. The tag is missing. I thought I was just being an idiot.

Yep 100% correct on the chokes. I have plenty of spare parts, so I'm going to rebuild the right one too. The right carb always made the engine hard starting, cold or hot. This morning when it was about 35° out, the engine fired right up! Never did that before in its life.

 

Hi all I have a 66 cj5 with the Dauntless, The number on my carb is on a trianglar tag, it is 7025148, then below this number is B3 and to the right of the B3 running verticle is the number 39, mine is like the pic on the right it is a auto choke that has been converted. Is this the correct carb for my Jeep?

 

http://www.oldcarmanualproject.com/manuals/Carbs/Rochester/2-Jet/Manual/index.html
heres some helpfull info on the 2g

 

Thanks for the link!! It helped me figure out I have a one barrel rochester and intake manifold. Any ideas?

 

NO !
You indicate that your carburetor is model Rochester # 702148.
This particular carburetor was used in 1965 by Buick on 225 engines with automatic transmissions.
When Kaiser began production of the 225 Dauntless in 1965 they initially installed Rochester #7025149.
Rochester #7025149 was used by both Jeep and Buick with standard transmissions during 1965.

Both the Rochester #7025148 and #7025149 are model BC which means they are a single barrel with automatic choke.
This carburetor yeilds a maximum engine output of 225 ft lbs of torque for the Dauntless 225.
Later the same year Kaiser began installing Rochester 2 Jets to replace the BC (single barrel) Rochester.
Rochester 2 Jets yeilds a maximum engine output of 235 ft. lbs. of torque for the Dauntless 225.

The single barrel Rochester model BC uses a single barrel manifold.
The 2 Jet Rochester model 2G or 2GC uses a double throat manifold.

 

you know your stuff about these carbs, will the summit 2gc's work on jeeps they're built for circle track racing? Have yu had any experience with them?

 

I'd like to know that too. About the Summit carb that is.

 

Thanks oldtime, is it worth the money to switch out the intake and carb if we only use our jeep for moderate off roading? Also how can I determine which engine i have?

 

Try a search. I'm sure that it has been discussed in detail. I know it is done with the number that is cast in the rear of the intake manifold.

 

Thanks, I found the v6 page my casting number if I read it correctly is 1358495 which I could not find, i will recheck the #s today.

 

If your 225 is currently running well then don't bother changing the carburetor nor the manifold.

The Rochester 1 B is VERY POORLY regarded.
It may be possible to replace it with a high quality 1 barrel such as the Carter YF.
Carter YF # 2467 S was used on Jeeps with the Super Hurricane 226.
It may be an excellent candidate for replacing the Rochester 1B on a Dauntless 225.
The cubic inch displacement is exactly correct and yes this effects the air/fuel mix ratio.
I have not checked on all specifics. Correct mounting flange and the throttle linkage may be an issue.

The other alternative is a correct application of the VERY HIGHLY regarded Rochester 2G.
A Carter YF possibly might yeild better MPG than a Rocester 2G but the jury is still out.

I suggest you first identify your particular engine.
The identification code is located on the right engine side upon a machined flat between the #2 and #4 cylinders.
It is a 6 to 8 series of letters and numbers that is lightly stamped onto the flat.

 

My casting # is 1358435 which according to the v6 page makes it 63-66 single barrel. The owner before me just put headers on and the gasket is in the way, will try tomorrow to get those #. It runs ok I have the adjustment screw 1 turn open it seams to idal best there but it is still rich and blubbers a little off of the bottom. Where does the vacum hose on the front of the carb suppsed to go? It was pinched off when I got it but it runs better with it open. Many thanks for everbodys help.

 

Rich fuel mix is associated with installing an otherwise correct carburetor intended for use with an automatic transmission.(AT)
When a carburetor is metered for use with AT it is typically metered approximately 1/2 size enriched
over the same carburetor calibrated for use with a standard transmission. (ST)
Operating at high elevations will only accentuate a fuel rich condition.

 

If I can't find a good correct intake manifold what do you suggest for after market rep-lacement.

 

The decision of "best" manifold is directly related to the chosen carburetor CFM rating, the intake valves, the compression ratio, etc.
In other words you are addressing VOLUMETRIC EFFICIENCY of "the charge" via the manifold.

Lest we delve into building a high performance engine I suggest that you limit your search to "original" Jeep Dauntless manifolds.
Specifically look for known Dauntless 225 intake manifold casting numbers of 1376398 or 1378704.