Wierd Weber Jets

[SpiderKen]

I finally got around to checking out my carbs and found out they have jets that I have never seen listed anywhere. Could this be yet another hidden remnant of PO insanity? Could this be the reason for the black sooty dot I leave on the pavement after a cold start?

The info:

1985 Spider (European) with 1600 engine. Two Weber 40 DCOE 107/A 3K08's

Now the fun part:

Air correctors: 180 (acceptable so far)

Emulsion tubes: F41 (WTF?)

Main Jets: 132 (Huh? I thought they made either 130s or 135s but 132?

Idle Jets: 55F21 (Double huh?)

The thing is that other than the black spots, the car runs great. I have suspected from the look of the plugs that it runs a little rich, but other than that and a puff of smoke upon deceleration I have no complaints.

I haven't looked at the starting jets or venturi's yet (any easy way to check the size of the venturis?

Anybody ever seen jets like this or have an idea why they might have been put in?

[120]

from the limited experience I have, what you see is typical for the alfa carbs. The very early cars had normal jets, but I have seen some unlisted emulsion tubes and jets on 105 cars.
The 132, like a 117 that I have is also normal, at one time you could get any number you wanted. As use of the carbs becomes less and less the numbers provided become more mundane. Who is going to make a run of jets that no one will likely buy?


I have a notion that alfa either spec ed or researched the jets and other gizzards for their requirements. Thus the odd ball unlisted parts.

55f21 = f21 with 55 mm aor
should read 0.55-f21

the emilsion tube number sounds like a dcnf number

the black spot could be the float level or rich idle (are you using the choke)

after syncing the carbs do you adjust the idle mix with the filter system attached

and this is just a question for anyone reading this post, Dellorto cars use the same internals as webers and I assume the same id numbers, but what about mikuini any chance someone has rebuit this with non weber parts?


randy
76 spider

[120]

Randy,
As far as I have seen, the Dellortos work like a weber but the pieces can't cross pollinate.

Bruce

[papajam]

Those odd (to me, anyway) jet/emulsion numbers may be the result of Webers refinement for a particular application? Don't know. The venturi size can be checked by looking in the intake side of the carb. The venturi size in mm is cast into the venturi. In this pic, the number in the 6 o'clock position says that this venturi is a 32mm.

[papajam]

Oops! Major brain fade. Forgot to crop.

[SpiderKen]

Thanks for the replys. I guess it was all done for a reason. I just got new gasket sets so I'll clean and adjust what I have and then in the spring when I start driving it more I'll order a new set of tubes and jets according to the Centerline chart and see if I can tell a difference.