Idler screw?!?!? (look at the bottom!)

[pauljdav]

Is this confirmed a 32 ADFA?

I have 2 32 ADFA and the hole you have appears to be where my carbs have an idle jet on the engine side of the carb for the secondary barrel. I am uncertain for its function as the secondary jet does not have an idle unless it it to offer a smoother transition for the secondary barrel opening.

I hope this helps.

Paul

[bradartigue]

The secondary jet controls transition from idle jet to main jet. Absolutely necessary.

[CHMMX]

Well is that what's supposed to go in that hole?

[rlux4]

CHMMX, have you downloaded Brad Artigue's wiring diagrams and "Fiat 124 Spider/Engine Maintenance and Modification"?
In addition to having at least two repair manuals, these two are essential to doing repairs on your car. The Engine Maintenance and Modification booklet has a whole section on carburetors, the first chapter is "understanding carburetors". There's a section in it on identifiying carburetors also. Go here: http://www.artigue.com/fiat/
and download both booklets if you haven't done so yet.
While I'm at it, it's been said before, but we all owe a big debt of gratitude to Brad. Thank's Brad, you've helped more than you know.
Ron

[CHMMX]

Thanks, that should help.