Webers from a 2056 to a 1.7L ? Options

[Literati914]

I have a 2056 GA engine that came with a set of Italian Weber 40 IDF's .. the engine was reported to have ran very strong when removed, I bought it like 8 years ago now. I never started the engine or have any experience with these carburetors. The engine combo is slated to eventually go into a sig. orange '72 that I'm doing complete rust repair, paint and body on (which'll take a while so, eventually).

In the mean time I have a non-running '73 1.7L that I'd like to get back on the road asap, and basically use as-is until the other car is finished. The thing is though, it has an old crappy looking single carburetor on it. I assume it needs a rebuild, I've never tried to start the car but the engine turns easily. I was thinking of rebuilding the dual 40 IDF's from the 2056 and replace the single carb on the 1.7 with them.

What kind of changes (needles etc) would typically be expected related to this move? Is rebuilding Weber IDF's even a DIY thing I should tackle? Anyone know helpful links or vids on doing so? TIA.

[Ninja]

You need the smallest venturis ever made for the IDF.

The 27s I have are better suited for a 2.0.

If you get the venturi size correct the normal main 130-135, air correction 200, and idle of 50-55 should be close.

Even a serious Raby engine used this same "normal" jet set up.

That engine was 2.3L and used 44s with 32mm vents.

If you could find vents in 26 or 25, they might work better.

The IDF is stupid easy to do simple carb overhauls on.

If you have throttle bearing issues, it's a BUNCH more problematic.

Most "used" IDFs need throttle shaft bearings IMO.

I actually like the single progressive 2 BBL, not for performance, for ease of configuration and basic proof of life.

It's also just as easy to rebuild and requires significantly less tuning and adjustment to make work. That was their "claim to fame" and it worked. A completely non-technical could bolt one on with success.

The single carb is a perfectly good system to get the car through resurrection or a new motor through initial break in.

I'd fix that critter up, use it on the 1.7 and maybe use it to break in the new motor before the IDFs.