New member. Thanks for having me.  Have a 31 PA that was a well running driving car prior to removing the wrong RJH carb and installing a DRT-08 209s. Upon having an immediate flooding problem I changed out the needle and seat and float was a leaker.  Carb was previously rebuilt a couple years prior to me finding it and it was fine in shape. While I had apart I sized the well jet to be correct (Off the DRT-08 209s Service sheet) and multi-jet to be correct.  The jet tube was not soldered to the screw so i did that as well as flared out the top of the tube to make a better seal. .  Back onto car.  Won't start.  Full choke and good battery won't start.  Check a couple plugs and are fine. Have fuel. Quick spray of starter fluid and fires over at 1/2 choke and high idle.  GOOD, let in choke and stays running at high idle. GOOD.  slowly bring down too idle after warm up and starts to stall out. Can't even get close to the idle RPM before it does.  Been told that I have an incorrect jet tube and mine is an aftermarket item with zero numbers on the screw but looking at a picture of the correct one I need a  11-120s jet tube. Mine has much smaller upper and lower holes in the tube. The well jet I am running is also the leaner one mentioned in the service paperwork.  I live in TX, warmer climate and 600 ft above sea level. Can anyone be of any help in finding the part I need?

These guys might be able to help you.  I believe they have rebuild kits or at least sell jets for the Rt08 Carb.  Anyway, maybe these guys can help you.  Bolting one on is the extent of my expertise.

The Carburetor Shop LLC
204 East 15thStreet
Eldon, Missouri 65026
http://www.thecarburetorshop.com/

No help on the jet tube. Tons of the chevy stuff though. DRT-08 209s was a one year only carb.  Might find a good BB1 to toss on until I can find this 6 dollar part that has me sidelined.  Missing best part of driving season here in TX

If you put the RJH Carb back on does it run ok.

It was running fine before I removed it. So I am pretty sure it would. It is the only change to the car. I wanted the correct carb for the car is all.   There are many different jet tubes for the applications the DRT-08 and RJH carbs but only one tube for drt-08 209s. Extra vacuum for the advance for the distributor.

Pardon my ignorance, but I am not familiar with the PA setup.  Does the vacuum for the distributor tap from the carb or the intake manifold ?  Could you have a vacuum leak some place.  What you are describing sounds a lot like a vacuum leak.  Unable to idle at low rpm.  I would think that an incorrect jet shouldn't create low vacuum.  You would either starve or flood the engine but vacuum should be OK.  Have you looked at the vacuum level ?

I know you have looked at this 15 different ways just trying to understand what's going on.

Think I might have it licked as the lower vent hole on the jet tube is undersized by 2 drill rod sizes. I have to drill it out to match the # in the service directive.   The upper hole is fine. So even at full choke to start it would not pull enough fuel in. I will yank it out this week and do it with the finger drill. Should be a size #62 drill rod. There are actually 3 of us on the AACA boards working on the same carb with the same problem. Getting the correct numbered tube is the next hunt. Mine is out of an old repair kit for Carter Chevy's I found out. Like 1925-26

On the vacuum, the manifold vacuum is strictly for the wiper.  On the acc pump side is a vacuum port just for the distributor advance.

Would you like to see some of the original service sheets and carb pics?

Sure, is there a link to the info.

No, have everything saved on my email and can't seem to cut and paste here

Sorry, You can't cut and past but you can create a pdf file and up-load the document.  But don't worry about it.., just get your car fixed.  It would be good to let us know what the final conclusion is and where parts can be found.

Many Thanks for posting, Vary interesting problem.

Chet