Sorting out my R90/6 (sprouty115)

Discussion in 'Airheads' started by sprouty115, Sep 13, 2017.

  1. Disston

    Disston ShadeTreeExpert

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    I see. So are the stalks shown in you past post OEM? Or are they Enduralast also?

    If you have OEM housings then OEM short stalks should fit.

    I don't have any here to examine but I think the longer original stalks had the length in the fatter portion of the stem, not the skinny part that enters the housing. With the stalk shown and the housing mounted the skinny part will will show and I don't think that is correct.

    Maybe used parts at this place in your endeavors would work better than aftermarket. The short stalks and original housings are fairly cheap used. S fairing longer stalks are very expensive. Very. Like sometimes around a $100 each.
  2. sprouty115

    sprouty115 Long timer Supporter

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    Yes, the stalks are OEM that I ordered from Ebay. The turn signals are Enduralast.

    Interestingly, Euro MotoElectrics also sells stalks, but only the long version. So I guess they're meant to work together. In fact I would have ordered the stalks from them, but they were $54 each and I happened to find the set on Ebay for $40 pair...just didn't realize they were different lengths.
  3. Disston

    Disston ShadeTreeExpert

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    So now you need original housings?

    I don't know what would work and cost you less. These problems are run into all the time when using aftermarket parts.
  4. sprouty115

    sprouty115 Long timer Supporter

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    Since the last post I've been out riding as much as possible and the bike has been running pretty well and I'm really enjoying it.

    It starts almost instantly, and now requires the choke (before it wouldn't start with the choke on at all). It takes a few miles to warm up, but I believe this is normal. I do however, have a slight hesitation as soon as the throttle rolls off idle. I've made small adjustments to the idle mix screws, idle stop screws and the cable adjusters, but I can only make it slightly less bad, and not completely gone. I've been at this awhile now and I feel like I have the basics covered (timing, valve clearance, fuel bowl height, etc,) but I'm not quite there yet. I did get a set of shorting sticks and will see if I can figure anything out trying to balance the carbs that way...




    In the meantime, I'm looking for a new seat (stock looking) - the foam on mine is shot and the trim has been replaced with an aluminum trim piece that looks a bit "off".

    So I've done a few searches, but I'm not seeing a definitive consensus. Anyone have an opinion? Other options besides what I have listed below?

    OEM - $650
    https://shop.maxbmw.com/fiche/DiagramsMain.aspx?vid=51889&rnd=07242017

    Wunderlich - $500/$550+
    http://www.wunderlichamerica.com/motorcycle/5253961.html
    http://www.wunderlichamerica.com/motorcycle/5255600.html

    Sargent - $350+
    http://www.sargentcycle.com/Seats-Accessories/BMW-Classic-Skins-Complete-Seats/VCA-966.html

    S. Meyer - $270
    https://www.meyer-bikes.de/index.php?page=details&art=52531233960b

    Mayer and Corbin are out - can't get past the non-stock look...
  5. sprouty115

    sprouty115 Long timer Supporter

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    Thanks, I'll be on that this weekend!
  6. Jim K in PA

    Jim K in PA Long timer Supporter

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    Motobins in the U.K. Has a pretty good selection. I've bought several seats from them, including a couple of their "pattern" replicas. I think the S. Meyer seats are what 'bins sells.
  7. sprouty115

    sprouty115 Long timer Supporter

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    Was leaning towards Meyer or Sargent. Thanks for the input.
  8. nobbylon

    nobbylon Long timer

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  9. sprouty115

    sprouty115 Long timer Supporter

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    Looks like the same seat as the Wunderlich link? Sort of wondering what the extra money buys me?
  10. nobbylon

    nobbylon Long timer

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    Yes I think they are the same. I’d ring meyer and ask them to send you a pic of the underside of their seat.
  11. PaulBarton

    PaulBarton Long timer Supporter

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    . Great use of the word! Are you an architect?
  12. sprouty115

    sprouty115 Long timer Supporter

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    Thanks for the suggestions. I rebuilt the carbs at the start, and I actually replaced at least one if not both idle screws (need to see what I ordered?), and all the orings, but it never hurts to check.
  13. Disston

    Disston ShadeTreeExpert

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    I didn't come up with this idea myself but I forget where I got it from.

    When doing Bing carbs and sometimes other things that are used in pairs on our bikes I always replace both items in each carb if one is bad. Say I need a diaphragm because one has a pin hole? I replace both because the other one is just as old as the one that failed. Maybe I could get by with only doing one but more likely I think the other one will go out pretty soon.

    Other things that I have encountered included an idle mix screw I had that had a bent tip. No idea how that happened. It was years ago and the bike came that way to me. Now the other carb had a good idle mix screw but the advice was to replace them both because these parts sometimes have design changes and manufacturing tolerence's and a new screw may be slightly different from the one that is 40 some years old.

    I know this borders on being too anal but I feel better sometimes trying to keep things balanced.
    sprouty115 likes this.
  14. Disston

    Disston ShadeTreeExpert

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    I do seem to have my own version of difficulties Plaka. And to be honest I think the PRs have better running bikes sometimes.
    Jim K in PA likes this.
  15. Jim K in PA

    Jim K in PA Long timer Supporter

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    Clever. :thumb
  16. sprouty115

    sprouty115 Long timer Supporter

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    At the risk of sounding over confident, I don't think I cut any of the o-rings during installation. I actually work as an engineer and we make automotive actuators, switches and sensors, so o-ring installation is part of my daily life. So when I was rebuilding the carbs all the shafts and screws got wrapped in tape and then greased. Everything went on very easily.

    As for float bowl fuel height. I'll give the jar a shot. I assume 1/2 from the top, plus the groove depth where the gasket sits is what I shoot for?

    I will admit there has been a bit of variability in the readings as I tried to see this in the past, which has always had me wondering if the float needle seat is damaged somehow (ethanol?)...
  17. sprouty115

    sprouty115 Long timer Supporter

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    Excellent Plaka,

    Just to be clear:

    - the bike is generally running well, but it doesn't seem as completely smooth as I think it could be.

    - along with that there is a slight, but noticeable stumble just off idle when excellerating.

    - the left carb idle mix screw is very nearly seated at the point the engine idles the highest, so it is backed out maybe an 1/8th of a turn.

    - the throttle axle o-rings were replaced. I noticed the small screws holding the butterfly in place were not staked on backside, so they needed to come out to get Loctighted (couldn't risk them coming loose and getting sucked into the engine). At that point I figured why not replace the o-ring.

    - both float needles are new.

    I unfortunately ran into a list of house chores that "needed my attention", and it didn't seem like it was up for debate, so this will get pushed out to next weekend.
  18. Bigger Al

    Bigger Al Still a stupid tire guy Supporter

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    Not to hijack the thread, but I want to send out thanks to Plaka for this post. My R90/6 had developed a stumble off of idle and nothing I tried would cure it. I spent a hour cleaning the transfer ports and that did the trick!
    Seems I can still learn something about this bike after 25 years of ownership.
    sprouty115 and WRC51 like this.
  19. sprouty115

    sprouty115 Long timer Supporter

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    Glad to hear that. I'm traveling for the next two weeks but I'll be on it when I get back.
    Bigger Al likes this.
  20. sprouty115

    sprouty115 Long timer Supporter

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    So it's been quite awhile since my last update but I've got a few more things sorted out.
    First off I think the syncing of carbs is good. Plaka's post above was very helpful and I took it to a local Airhead tech day and they made one further small adjustment and it seems good (finally!)

    I also think the more I ride it, the better it seems to run, for some reason.

    Anyway, here is what else has been going on:

    - Gauges fully serviced from @Wirespokes.
    20181129_153140.jpg

    - And a Kat Dash to replace this...
    20181129_153049.jpg

    - And since I was refreshing the gauges, I put in new cables for both the speedo and tach. So now it looks like a proper bike again.
    20181201_144831.jpg

    - Then...because I was spending time looking at bikes like these...
    20190513_153931-COLLAGE.jpg

    -...I put an order in at Flatracer.com for their R90S fairing...
    4635687279.jpg

    So that leaves me with a bit of work to paint and install, but I'm looking forward to it!

    After that, when my bank account recovers, I'll be replacing the seat, as the original foam has softened to the point that it's really not comfortable.

    (BTW, Flatracer is out of the UK, so don't confuse Euro with GBP when doing a conversion to US dollars or you'll get a big surprise when it posts to your PayPal account, DAMHIK!)

    Oh, and I also ordered two more bars from Tucker Rocky as I still think the ones currently installed (Flanders BMW Flat Sidecar Bar) are too low and too far forward. They were only $25 each so if I don't like them it's not too big of a deal.