O ring needed for mixture screw???

Discussion in 'Airheads' started by Padmei, Apr 23, 2012.

  1. Padmei

    Padmei enamoured

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    4,099
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    Hi all.
    My LHS mixture screw (36mm bings off R80GS) is missing a spring. What purpose does this spring serve?
    Also in the bing book an O ring is shown between the spring & screw. I am unsure if mine had them originally - should they have? I am chasing down a revs getting hung up problem & trying to eliminate problems.
    Cheers
    #1
  2. Pete-NZ

    Pete-NZ Been here awhile

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    Oddometer:
    976
    The spring stops the screw vibrateing out by keeping preasure on the thread..
    there most lightly was a 0-ring...
    #2
  3. lockyv7

    lockyv7 Long timer

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    I only just rode a 100GS home on the weekend and it has a revs hung up problem, when it gets hot it wants to idle really high sometimes, i was thinking it was in the bean can, maybe the weights advance staying on or something like that.
    I am sure someone will be along shortly to either give me or you an answer.
    #3
  4. Voltaire

    Voltaire Titanium and Ceramic Hipster

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    As mentioned the spring and o ring stop the screw working loose and sealing at the same time.
    Idle slow to drop is often due to air leaks, may be time to replace the carb/head rubber.
    Throttle cable not letting the butterfly valve close....throttle shaft worn/leaking.....
    #4
  5. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Adjust the carbs when they're fully warmed. When the idle is high, that's the time to adjust and synch them. Most likely, that will cure the situation.
    #5
  6. boxerboy81

    boxerboy81 Stay Horizontal

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    Ride it for 20-30 minutes, then tune the carbs. Tuning when not warm enough will cause a high idle.
    #6
  7. Padmei

    Padmei enamoured

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    Just to confirm with those of you that have the same carbs - is there def is a small o ring that sits on the smooth shaft between the thread & the point & not just the one that sits at the end in its' own recess?
    #7
  8. Box'a'bits

    Box'a'bits In need of repair

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    Nope, just sits in a recess near the threads.

    Does that book cover multiple Bing carbs, or just your model? The carbs are 32mm btw.

    Put up a photo if you're still not sure
    #8