Technical Rochester singles; what to do!?

I have these on a 38 chev (235). These were put on well before my time. The truck runs fine AFTER I get her going. This almost always means I have to manually pour about an ounce of gas (*I use premix for the weed eater!) in the carb to get her going.

-The chokes are not hooked up. Id rather not hook them up if possible.
-Only ONE of the accelerator pumps is working. Only one is priming when viewing down the barrel while pumping the peddle.

I am not sure how I should approach this. I am pretty sure it would run fine (*even better?) on one carb only.

Should I:

-Rebuild both and run as duals?
-Rebuild one and block the other off?
-Buy new carbs and not f- with rebuilding?

Is there a 'one kit fits all' for these carbs or will I need to track down a specific kit?

Tks for any advice!

~JH

 

Buy kits to rebuild them, and hook up the choke.

 

You need the choke hooked up ( even if only in one carb

You need the phenolic spacer between the carb and the intake

Do you have the intake heated? Pics are not clear.

And yes get the carbs built, they are both falling apart from the sounds of it.
Easy carb to build

Look for carbking he’s on this site and has good kits.

You can run the engine on one carb but it runs better in two and is slightly more fuel efficient as well.

If you can find them a matched set of carters or better yet zeniths would run a bit better.


But the Rochester’s are a good carb, cheap and easy to maintain.

 

Hook up the chokes on BOTH!!!

It will start MUCH easier.

Once you get it so you can enjoy it, THEN decide if you want to rebuild or not.

If you have no hesitation on acceleration after warm-up, then, while I would personally want both accelerator pumps functional, perhaps one is sufficient on the 235.

Should you decide to rebuild, no, there is not a "one kit fits all"; HOPEFULLY, at least one of the triangular identification tags will still be in place.

(Opinion) there are MUCH better carburetors available for your application (and have been for more than 75 years!).

Jon

 

Speaking from considerable experience with Rochester BV/CV carbs in dual carb applications, I found them completely lacking in adjustability and don't have the necessary internal features that are modify-able to provide a tractable fuel induction system.
To be more specific: BV/CVs lack intermediate or transition ports for controlled delivery of emulsified fuel through the idle to part throttle acceleration. Secondly, the power valve is prematurely opened because each carb senses only half as much vacuum in a dual carb application. Vacuum is required to keep the power valve piston's pin plugged into the power valve jet. This vacuum is being opposed by a spring. Even experimenting with lighter or shorter springs, while improving the overly rich condition, still doesn't provide smooth transitional (stumble free) operation. After several years of messing with them, using a gauge panel I made that included a vacuum gauge, a tachometer and a wide band air/fuel meter that I could set on the seat beside me to watch what was happening with the carbs while driving in varying drive modes, I came to the conclusion these carbs have too many shortcomings to bother with anymore.
The solution is to go to "STOVEBOLT" and buy a pair of Holly/Weber progressive 2 barrel carbs, adapters and linkage. www.langdonsstovebolt.com 586-739-9601
Best regards and good luck with all your endeavors, KB.

 

^^^ THIS ^^^

 

Better heads than mine have already responded.
Yes, you need a choke. At least hook up a cable to the front carb. Simple and cheap.
"Block off a carb?" NO! Fuel distribution is the main advantage of a two carb system, and would be totally destroyed.
Nice intake you're running, BTW . Repro Offy's and Fentons lack that smooth shoulder radius.

 

I have to ask because I can't tell. Progressive linkage or do both carb's open and close equally?