BBD carburator rebuild - help needed

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  1. Machmeter1

    Machmeter1 FABO Gold Member FABO Gold Member

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    I am about to rebuild an 1969 BBD carburator 4608S. Following problem accured: when removing the Venturi cluster cover, I found out that the two needle style brass pick up tubes were loose and I don't know if they were even in the right position. I attached a picture of the way they came out (on the two inner holes) and another possible option (parts clean), where they would also fit (outer holes). They have a tight fit on the outer holes but are loose in the inner holes. Maybe someone of you has a reference picture of this cluster cover. There are plenty of pictures of later BBD carbs out there, but I could not find one of this particular carb. The only picture in the service manual showing the Venturi is blurry/to dark.
    Thanks Wolfgang

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  2. Machmeter1

    Machmeter1 FABO Gold Member FABO Gold Member

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    Looking at manuals for BBD carburators doesn't help neither. The drawings are not accurate and show also two different locations.

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  3. Garrett Ellison

    Garrett Ellison Amateur driver on public roadway, do not imitate.. FABO Gold Member

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    B01829A8-95B5-4DC9-B754-C2F919C44C36.jpeg 0C4DC200-84F3-4127-9586-7551A3397B1E.jpeg The position shown is correct, they may have to be staked in place with a center punch on the booster body to retain them. Just be careful when staking to not do it near any internal passages. Here’s an early factory booster assembly for comparison.
     
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    • Garrett Ellison

      Garrett Ellison Amateur driver on public roadway, do not imitate.. FABO Gold Member

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      I believe your second drawing in the rebuild kit diagram is of the later booster assembly, starting in 1973 IIRC.
       
      Last edited: Jan 7, 2020
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      • Machmeter1

        Machmeter1 FABO Gold Member FABO Gold Member

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        Thanks Garrett, the Venturi cover in your picture is slightly different from the one I have , but I have exactly the same piece in another BBD carburator.

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      • Machmeter1

        Machmeter1 FABO Gold Member FABO Gold Member

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        The carburator I am rebuilding is slightly simpler than the spare one I have. On the spare carburator the Venturi cluster has no wide brass tubes. Just the horns on the Venturi cover and the two in question, needle style tubes.

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