Exhaust Star Nut Question

Discussion in 'Airheads' started by kevin g, May 15, 2018.

  1. kevin g

    kevin g Been here awhile

    Joined:
    Dec 29, 2010
    Oddometer:
    405
    Location:
    San Diego
    My R100 Monoshock exhaust does not seem to be done correctly.
    ExhaustNut.jpg
    There is only the clamp ring and no compression ring. The taper on the clamp ring seats in a taper on the star nut but all of the pictures and illustrations I find show I need the clamp and compression ring. Is that correct?
    #1
  2. UnclePete

    UnclePete Been here awhile

    Joined:
    Nov 13, 2014
    Oddometer:
    676
    Location:
    Plumas County , CA
    Yes , there is a solid ring and one with a split . Both have a taper ; taper into each other . When the nut is tightened , it squeezes the split ring into the solid one , and it tightens on the header pipe .
    #2
  3. kevin g

    kevin g Been here awhile

    Joined:
    Dec 29, 2010
    Oddometer:
    405
    Location:
    San Diego
    Thanks Uncle Pete. This bike has had a number of interesting surprises for only 12K miles when I got it.
    #3
  4. bmwrench

    bmwrench Long timer

    Joined:
    Nov 10, 2006
    Oddometer:
    5,446
    The single compression ring was used in 1987 only. It's a copy of what the R65 used. It worked on most of the bikes, but I had one customer whose left header wouldn't stay put. We finally converted to the normal arrangement, which requires a different nut. Yours looks like a combination of parts.
    #4
  5. cycleman2

    cycleman2 Long timer

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    Jan 18, 2010
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    Location:
    Alberta, Canada
    I've seen that set up on R65, just the one ring. If you check the parts fiche for the various years you'll figure out which one had 1 and which one had 2.
    #5
  6. Big Bamboo

    Big Bamboo Aircooled & Sunbaked

    Joined:
    Sep 29, 2010
    Oddometer:
    12,958
    Location:
    Big Island of Hawaii
    Do all R65 use the single ring? I have a friend here with a '86 Monolever R65 with perpetually loose headers.
    #6
  7. bmwrench

    bmwrench Long timer

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    Nov 10, 2006
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    5,446
    Yep. Tighten the exhaust nuts with a mallet.
    #7
  8. Big Bamboo

    Big Bamboo Aircooled & Sunbaked

    Joined:
    Sep 29, 2010
    Oddometer:
    12,958
    Location:
    Big Island of Hawaii
    We've tried, but it feels like the nuts are seized on the threads... Plan on cutting them off and dressing the threads.
    #8
  9. ME 109

    ME 109 Long timer

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    Jun 25, 2009
    Oddometer:
    6,861
    Location:
    Albury Australia
    Is the single ring a split ring? If it is, maybe make the gap/split wider.
    #9
  10. ccmickelson

    ccmickelson MonoMania

    Joined:
    Dec 11, 2013
    Oddometer:
    1,235
    Location:
    Fanta Se
    Both of my '87 R80's had the single compression ring. I never had a problem with them loosening. I've always tapped the nuts tight with a mallet but I wouldn't say it required excessive force.
    #10
    brittrunyon likes this.
  11. bmwrench

    bmwrench Long timer

    Joined:
    Nov 10, 2006
    Oddometer:
    5,446
    I had one customer/friend whose right header slid out of the head regularly. It must be admitted that his bike was being ridden "within an inch of its life", but we finally converted it back to the original arrangement, and that ended that problem.

    That R80, later equipped with 1000cc cylinders, spent its days chasing my K-Bikes. Our annual trips to the South found it spinning down the road at 6000 RPM for days, with the only problem being that it used more fuel than my Ks! For years, it did it in the company of 1050 kitted R80, which also did this with aplomb.
    #11
    Jim K in PA likes this.