Twin-H carb issue

54Hollywood

Hi everyone.  Here's the thing.  Recently had the Twin-H carbs rebuilt and I'm having a few problems.  The car starts just fine but doesn't want to idle.  I fiddled with the settings a bit and now it idles fine until it starts to warm up and then it dies.  I don't have access to a Uni-Syn but I was hoping that those of you who have dealt with this before could provide some suggestions about how best to solve this problem.  The carbs are WA-1, 968S if that helps.  Thanks in advance.

Tim in WI.

Glowplug

A unisync allows the twin carbs to be more precisely balanced. The principle it operates on is balancing and maximizing vacuum.
Use the procedure provided at this link. Place a vacuum gauge at the balance tube connector. Adjust the carbs per the instruction by looking at the vacuum gauge and maximize the the readings.

http://www.hudsonrestoration1948-54.com/TWINHADJUSTMENT10001.htm

Glowplug

The Maas folks have the unisync:
http://21stcenturyhudson.net/products2.htm

lostmind

You can use a piece of vacuum hose , 3/8 " , that is long enough to reach from carb to your ear.

If you put the hose in the same spot on each carb , you will be able to balance them by getting the

sound the same. I think it's as accurate as the unisync  once you practice.

I worked at an import dealership in the 60's , had a lot of multi carb set ups.

54Hollywood

Hi again.  I appreciate all the good input but the basic problem is that she won't hold an idle long enough for me to try and balance the carbs and I haven't come across enough info regarding the initial settings for the carbs.  The automatic choke is set at 1 point lean and the idle mixture screws are two turns out from the seat but she won't idle.  What am I missing?  Thanks.

Tim in WI.  

hudsontech

Hi Tim.  Give this a try - close both idle screws, then open both 1/2 turn.  Try that - if that doesn't solve the problem go to 1 turn out - then 1-1/2.  I don't have a shop manual for the 968 carb, but the 1951 shop manual says 1/2 to 1-1/2 open on the idle screws and that's pretty close to most applications.
If this doesn't work then the problem is elsewhere.

Hudsonly,
Alex Burr
Memphis, TN

lostmind

Most likely a vacuum leak. Try tightening the manifold bolts as a starting point.

Frankvintagefullflowcom

At the risk of insulting someone, somewhere (that's never stopped me before) there are quite a number of things that can be done incorrectly in the process of "rebuilding" a carb.....the WA-1 is no exception. If your rebuilder wasn't adept at those carbs and in possession of the proper set-up tools, it could be a factor. Simply "kitting" them may not be enough, although of course, I don't know if that is the case.
A quick check for manifold vacuum leaks is the old "spray a shot of carb cleaner" at any suspect area and, if the engine speeds up, it's an air leak.Check for a ruptured Vac Advance diaphragm, although that should not be extreme enough to prevent idle altogether, equalizer tube gaskets and hose connections for the vacuum booster side of the fuel pump (if so equipped).
It does sound like too much air as opposed to too little fuel. Either way it smells of lean idle mixture.
F

Kdancy

http://www.google.com/search?q=uni+syn+carb+synchronizing+tool&ie=UTF-8&oe=UTF-8&hl=en&client=safari

Uni sync

hudsontech

Tim, I been talking to Walt Mordenti about your problem - here's what he has to say -
Alex
I got on but can't send an answer.  Tell him he has idle jets blocked
from varnish in his gas.  Did he install a fuel filter before the carbs
when he installed his rebuilt carbs?  Let me know his answer, Walt.
You can contact Walt Directly at waltmordenti@aol.com

Hudsonly,
Alex Burr
Memphis, TN