Carburetor Rebuild - Is it worth sending out?

Discussion in 'Old's Cool' started by BrokenR80RT, Feb 4, 2011.

  1. BrokenR80RT

    BrokenR80RT But I'll fix it.

    Joined:
    Oct 13, 2010
    Oddometer:
    157
    Location:
    Michitucky
    Yes sir, just home from the swim meet. Son did great. I'll take your advice and not pull the head unless I can't see inside or if I see something alarming. But it seems to run fine. I know my compression is about 125-126 on both cylinders which makes me confident no real damage has been done, unless I am wrong here. Maybe I'll borrow a boroscope from work for a better look for scratches, dings, or scraped areas inside the head.

    The piece was laying in the step area where the plastic tube meets the carburetor. When I saw it, I felt it asking me to take the bike out and introduce alot of airflow so it could wreek havoc on my engine. Glad I found it first.

    In hindsight, I wish I would have spent more time yanking the bike apart when I first got it. The PO admitted that he wasn't very mechanically inclined, but had receipts from service done by BMW Detroit.....Hmmm.

    Since I have no idea of the part's origin, I'll go ahead and do the rebuild and inspect the heck out of it. This will get me back again to the point where I will also seal better where my metal boots attach to the airbox w/RTV (previous post, which you replied). Probably should have taken it all apart back then too, but that was a half off thing I did on the intake to clean the exterior a bit. I really tried not to disturb the carbs.

    Thanks for your replies, everyone! I love good advice.

    :nod
    #21
  2. Bill Harris

    Bill Harris Confirmed Curmudgeon

    Joined:
    Sep 20, 2008
    Oddometer:
    8,676
    Location:
    backwoods Alabama
    I got my /5 in '73 and the local gas stations started introducing gasohol (ethanol-laced gasoline) in the late '70's. My original floats "sank", weighed in a +5 grams, and were replaced with new in 1980 and I've always assumed that the gasohol got them. I generally replace floats every 5-10 years "just in case", but honestly I've not had problems running gasolhol periodically for the past 30 years.

    Bing does have floats made with a black, alcohol-resistant plastic foam. But at $30 apiece, I'll wait til I have problems with the "standard" floats.

    The Bing independent floats, OTOH, have never beeen on my bike, but they have caused untold misery on customer's bikes and have been the subject of many critical threads in the 'Net. They get a thumbs down.
    #22
  3. supershaft

    supershaft because I can

    Joined:
    Sep 9, 2010
    Oddometer:
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    Location:
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    That pin looks like it could be the center pin to the older style crank breather? That or a front main bearing locating pin?

    Bing has a number of "solutions" to problems that don't exist. The "solution" then has its own problems!

    Keep your stock floats and adjust the float level correctly.
    #23
  4. The Raven

    The Raven Banned

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    That would make sense as it has access to the carbs I believe, and the getoff.
    #24
  5. BrokenR80RT

    BrokenR80RT But I'll fix it.

    Joined:
    Oct 13, 2010
    Oddometer:
    157
    Location:
    Michitucky
    Supershaft,

    Can you explain this a little further. I looked at the vent sysem + block micro-fish. I don't see any such pin. How old do you mean when you say older style? I have an 83 R80RT.

    Thanks!
    #25
  6. matteo

    matteo HPM

    Joined:
    Apr 30, 2005
    Oddometer:
    499
    Location:
    San Jose, CA
    I found that very dowel in my oil pan. It was a mystery at the time. the theory was it was the main bearing locating pin. It's been three years and no problem. It may have been in the oil pan since day one of the bike. Now that you found one in the carb, maybe BMW just placed a few of these as an easter eggs for us to find.
    #26
  7. BrokenR80RT

    BrokenR80RT But I'll fix it.

    Joined:
    Oct 13, 2010
    Oddometer:
    157
    Location:
    Michitucky
    I saw nothing at all wrong inside the head due to this wtf dowel pin :clap. I re-torqued my heads, which surprisingly were loose by .5-.75 turn at the bridge bolts, then reset my lash.

    Dang, if I had thought in advance I'd trash the center stud on the rocker cover, I would have it back together with my shiny, refurbished black covers. The studs are on order with a bunch of other stuff I also needed from MaxBMW. Dreaming about M&M's already.

    My carb re-build kit is on the way from Bing in Kansas. I opted to stay away from the independent floats from everyone's advice:ear. An electonic balancing manometer is also on it's way from Max.

    But having all that, my tank is still at the body shop with my other faring parts. I won't rush the body shop as I originally promised this to be a "winter" project for them. I cannot wait to play.

    Thanks!
    #27