Weber 34 DAT 2/250 carburator

[Sampaio]

I have a 1981 Lancia Beta Coupé 2000, originally from Belgium, that comes with a Weber 34 DAT 2/250 carburator. I did a major overall to the carburator and everything seems to be working fine. Nevertheless I found out so little information about this model and i had so much trouble finding out what goes where that, to eventually facilitate others, I decided to provide the main aspects of this specific model in a few pictures. Sampaio

[pi3.14]

Thanks for the very clear pictures. I must start adjusting my Beta Weber and it will be a great help.
Do you know if the carburator loses a lot of fuel after standing still for 3 weeks?

Paul

[Sampaio]

I'm not aware of any carburator loss of fuel after some days.

[SubGothius]

Was just referred to this thread and thought I'd offer some correction/clarification:

In the 5th photo down, labeled "without solenoid, without choke", the vacuum port on the right is mislabeled (re: connecting to the "thermostatic control unit") and should actually connect to the vacuum advance capsule on the distributor. This is a "ported" vacuum source that only gets vacuum to apply ignition advance when the primary throttle butterfly opens.

The thermostatic control unit under the intake snorkel should connect to a thermovalve on the bottom of the main air filter housing, which in turn connects to any available manifold vacuum source.

[Sampaio]

Reply to the previous post. No and yes. My 1981 Lancia Beta Coupé 2000 (from the Belgium market) comes with a Bosch electronic ignition system and the distributor has no vacuum advance capsule. Consistently the installed and original Weber 34 DAT 2/250 carburator has no "ported" vacuum to the distributor. And yes, in this specific carburator the rear port is a "ported" vacuum that could or should connect to one of the two small pipes on the bottom of the air filter assembly (see third picture), that are part of a red thermovalve marked "AC", for italian brand Auto Clima. And from there another connection should go to the thermostatic control unit. This is how it should be, no more no less, in my specific car with this specific carburator. It so happens that in my car the AC valve is not functioning anymore. So I decided to bypass it and i didn't explain this contingency in the picture but i do it now. Well, this is for my car, and sometimes I have more doubts than certainties. But one thing is sure. There are a lot of carburater variants and the devil is on the detail.