Breather Valve Missing?

Discussion in 'Airheads' started by Niko, Mar 12, 2018.

  1. Niko

    Niko Adventurer

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    Ahoy, Asphalt Sailors
    So I got curious that my drainback hole might need cleaning, and what the breather valve looks like. Since I have never been into the top of the engine, it seemed like a nice way to spend some winter hours, so I began disassembling my 1981 R80 G/S. To my surprise, when I lifted the cap, there was nothing there. I've put just over 11k miles on this wonderful little machine, with not a hint of engine trouble. Obviously doesn't affect performance, but what other gremlins might be lurking by running without this valve? View attachment 1136294
    #1
  2. UnclePete

    UnclePete Been here awhile

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    I have had several Airheads including an '81 R80 G/S , and have never had a need to look under that cover .
    Your link shows an error message .
    #2
  3. Solo Lobo

    Solo Lobo airhead or nothing

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    Did you look under the rear cap or the front one?
    #3
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  4. Niko

    Niko Adventurer

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    The error was the picture I posted then removed (I think)... The cover I lifted was the front one. Duh. Never having been there before, I just figured it was the one with the breather hose (breather...hose...made perfect sense at the moment). After a bit more research, I pulled the rear cover and lo, there it was. Now I was curious to see if my bike had the famous 'disk' that starts making noise after a while, of if I had the updated reed valve, which I do. It's a bent rectangular piece of metal held in by one screw. From Oak's articles I have read, the 'draindown' hole is beneath this valve. Question is, should I now try to extract the valve to have a look at the hole?
    #4
  5. IdahoAirhead

    IdahoAirhead Been here awhile

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    You are already there. Why not check it and cross that off your list?
    #5
  6. hotwheels22

    hotwheels22 motorradRP

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    i found this to be crazy hard to find. veins of oil on the bottom and it is tiny. if i remember correctly it was about a third of the way from the back wall...
    #6
  7. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

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    I will admit my confusion at first reading this thread. I was picturing the massive cavity below the breather and wondering how it could get clogged, but snowbum to the rescue!

    [​IMG]

    I really should check this hole in my R90 based on the symptoms described here: http://bmwmotorcycletech.info/oilsketch.htm
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  8. RGregor

    RGregor Been here awhile

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    On an R90, if it's stille the original housing, you won't find that hole. That came with the /7 models.
    The /5 and /6 have another breather system without that additional chamber.
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  9. bmwrench

    bmwrench Long timer

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    At the risk of repeating myself, I have not yet seen one of those holes plugged.
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  10. Arktasian

    Arktasian Lets call it Naturalized

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    To commemorate the passing of Stephen Hawking, and given the dark nature of any oil residue in that area but its open vortex behaviour - perhaps we might dub it "The Black Hole".
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  11. RGregor

    RGregor Been here awhile

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    Some facts can't be repeated too often ...
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  12. Niko

    Niko Adventurer

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    heard that removal of the breather valve can be a bear. Have you done this?
    #12
  13. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

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    No wonder I was having such a tough time picturing it. I recently replaced my breather and saw no such thing.

    I'll be quiet now.
    #13
  14. Niko

    Niko Adventurer

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    great pic. Thanks!
    #14
  15. 190e

    190e Long timer

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    Early R45/65's don't have it either.
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  16. cycleman2

    cycleman2 Long timer

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    If you remove the reed valve, you will have to replace it as one usually ends up buggering it up during the removal process You might be able to undo the small screw and lift the reed portion of the valve and be able to see the hole. If there is no pool of oil, then everything is working as it is supposed to.
    #16
  17. bmwrench

    bmwrench Long timer

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    People make this harder than it is. A slide hammer and a hook get them out a trice. Literally-it usually takes three shots with the slide.

    The drainback hole is forward of the valve in a settling chamber. There's no need to remove the valve.
    #17
  18. RGregor

    RGregor Been here awhile

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    Early or late, I've never seen any small engine housing having one.
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  19. Niko

    Niko Adventurer

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    After a long absence, I have returned to this thread. You are perfectly right, I saw the breather hole, checked it and it was clear. Now, ready to close everything up. Just wondering about replacing the gaskets, one of which is torn. Are these cover gaskets available separately?
    #19
  20. cycleman2

    cycleman2 Long timer

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    Yes. Either your local BMW dealer or from a place like Motobins in the UK, maybe some other independent shop near you that works on airheads. Or you could make your own, not hard to do.
    #20
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