Rejuvenating needle valves & carb boilout

Discussion in 'Motorbike Technical Discussion' started by Nomen Nescio, Mar 15, 2006.

  1. Nomen Nescio

    Nomen Nescio Guest

    It wasn't too long ago when a carburetor overhaul kit for a Chevy-Six
    Rochester 1-barrel cost all of eight dollars and included needle valve &
    seat, acceleration pump, all gaskets, balls, and springs. Even a float
    setting gauge. So, it was customary to replace everything furnished by the
    kit, whether it needed it or not, just to be safe. Well, those days of
    cheap parts are history.

    A Bing was flooding. Turns out it was the needle valve as you might
    expect. Needles and seats get beat up from all that vibration and fuel
    deposits from long storage. A check online shows the needle only, less
    seat, is a whopping $15 plus shipping. No way, particularly since it may
    be the seat that's bad, not the needle! Here's how to fix a leaking
    needle valve, solid brass or Vitron, makes no difference. With the float
    off and the needle free, slip a short length of heat shrink over the
    tang-end of the needle. Dip the Vitron tip in Clover Valve Grinding Paste
    (Fine). Now insert the needle into its seat and turn the needle by the
    heat shrink in an oscillating motion as well as circular motion. Do this
    for about 30 seconds. Then wash out the grinding compound flush with
    gasoline through the gas inlet. Then, test: With the float in place and
    the carb body inverted, connect the gasoline line. The weight alone of the
    float will provide a leak-free seal if the needle dressing operation was

    The above described servicing procedure is unique and has never before been
    addressed in print or on the Net.

    In general, carburetors can be "boiled out" without replacing ANY parts, if
    those parts are in working order. IOW, if the needle doesn't leak, leave
    it alone. If it leaks, lap it with grinding paste. If that fails
    (doubtful), replace it with the expensive part, if available. Gaskets, if
    intact, will not leak if reused. Balls, unless pitted are also okay to
    reuse. If a part is reworked, add 50% of the new cost as a "service
    charge" for you guys in the business.

    As you will find if you are a scientific mechanic as I, 99% of carburetor
    troubles are clogged fuel supply jets (main or idle) and clogged air
    bleeds. Sediment and gasoline gum from long storage are the culprits.
    Always add gas preservative for winter storage. Now that Spring is almost
    here, there will be an awful lot of carburetor jobs; using the
    recommendations in this post will save you enough money to buy plenty of
    gas for many enjoyable hours of motorcycling pleasure.

    Nomen Nescio, Mar 15, 2006
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  2. Nomen Nescio

    Hank Guest

    what kind of crack are you on????!
    a bunch of other loony drivel

    prices have gone up since '75, so have wages, so???

    wtf, happy trolling!!
    Hank, Mar 17, 2006
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  3. Nomen Nescio

    humanid Guest

    That sounds cheap to me, they last for many many miles and the
    market is much more specialized. I have at least 130,000 on my Bings
    and the seats are fine, I've rebuilt the carbs once. It's been awhile since
    I've read the terminology but I think you are referring to the float valves,
    they have a rubber seal thats cone shaped and I can't imagine that
    wearing the seating surface down. Seems like you'd be overflowing long
    before that could happen. A total carb rebuild kit is pretty cheap last
    I did it and probably well worth the effort.
    humanid, Mar 20, 2006
  4. snip bullshit...nothing left.

    You can do better than that Nomen. I have seen your posts before and you are
    slipping with your posts of destruction.
    R. Pierce Butler, Mar 23, 2006
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