Bing rebuild question......

Discussion in 'Airheads' started by daveoneshot, Apr 19, 2013.

  1. daveoneshot

    daveoneshot Been here awhile

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    Rebuilding a pair of 32 mm Bings for an R 100/7. What's the best way to lock in the little screws that hold the butterfly disc to the throttle shaft ?? Thanks in advance, Dave.
    #1
  2. squiffynimrod

    squiffynimrod maximum shrinkage

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    It's recommended to peen over the threaded end to physically distort it so it can't back out.
    #2
  3. Plaka

    Plaka Brevis illi vita est

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    Put a big flat punch in the vise to use as an anvil, set the screw head on that and kiss the other end of the screw with a dull chisel, very lightly, to stake it in place.
    #3
  4. brocktoon

    brocktoon Been here awhile

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    I've heard of them coming loose and getting sucked into the engine. Folks who do this for a living can speak to the frequency/likelihood of it happening.

    I used loctite on mine.
    #4
  5. disston

    disston ShadeTreeExpert

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    I have also used locktight but the proper way is with peening.

    CanadaBiker- I have a feeling that you backed the original screws out with out undoing the original peening? When these carbs were put together the first time those screws were peened in place to insure the tiny screws wouldn't come out. When rebuilding if the deformed screw is removed the threads in the shaft will be deformed and likely loose.

    The peening is removed with a file. If they were properly peened originally the shafts will be reusable. You should use new screws. Often times the shafts won't survive or rebuilders change them any way. I have changed them.

    The new screws are longer than needed. I have a small saw blade that fits in the bore and can cut the screws down to size.
    #5
  6. chollo9

    chollo9 Screwed the Pooch

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    It's not that they would back out, it's that damage that would occur if one did and got sucked into the engine.

    Methods vary, I'm sure, but I use a very sharp 3/16" chisel to make a cut/deform the edge of the threaded end. The relatively large burr formed will not allow the screw to pass through the rod if it comes loose.

    I do not attempt to peen the screw in order to prevent it from loosening.
    #6