Weber jet sizes

[Colin Angell]

I have a 365 GTC which has tripple DFI/7 carburettors. As with so many, these have been played with over the years and whereas the car runs ok I know that the set up of the carbs is not correct. Can anyone help me by telling me the "standard" jet sizes, as originally fitted. That would give me a good starting point for further development.

[Colin Angell]

Oops, sorry! They are 40 DFI/7. I believe there were a few late cars with these carbs, rather than 40 DFI/5 which I know are more common.

I started to take a closer look because of a nagging fuel leak to the rearmost carb union. I soon discovered that heavy hands had stripped the threads, so I have started a proper overhaul.

I have machined a simple back-plate to hold the top of the carb on the cross-slide of my lathe. That way I have been able to very accurately centre it and bore it out to take a threaded insert. There isn't much metal there so I was too scared to drill by hand!

Rebuild is going ok, but I would dearly like to get hold of the original jet sizes.

[Michael Bayer]

As a point of reference my FAF Shop manual says for the Weber 40DCZ/6 the venturi is 28mm, main jet is 1.35mm, air bleed jet is 2.00mm, idle jet is .60mm, idling air bleed hole is 1.25mm, choke 3.5mm, pump jet .60mm, pump stroke 4.5mm, pump outlet hole 0.5mm. Hope this helps, Michael Bayer 1967 330GT #9727

[Jimmyr]

Is Pierce Manifolds still in the Weber business?

[Colin Angell]

The choke size on the 40 DFI/7 is 32