Bringing 74 R90S back to life after sitting 30 years

Discussion in 'Airheads' started by _cy_, Sep 30, 2011.

  1. xavier296

    xavier296 Alaska n'Back

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    Now that is awesome! A video scope is not in my tool list, but should be!!! I'll put it right behind the plasma cutter and the band saw.
    #61
  2. bringenufgun

    bringenufgun Been here awhile

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    some of the stubborn rust/corrision on the spokes that can't be removed with compound/scotchbrite/elbow grease can be tackled first with a brass brush either by hand or on a cordless drill. works a treat on some of the heavier chrome plated parts like headers, fenders, wheels and handlebars. too.
    #62
  3. bringenufgun

    bringenufgun Been here awhile

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    that photo looks eerily like the ones from my last colonostrophy. both clean as a whistle:D.
    #63
  4. Disston

    Disston ShadeTreeExpert Supporter

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    I think the price of video scopes has come down a little. Just a guess but I think a cheap one might be 5-$600. That one doesn't look so cheap though. I'm realistic, this item is not on my shopping list.

    I use the well known product, Naval Jelly, on rust. You can use Phosphoric acid, I think, but I don't know the concentration. It is the active ingredient in Naval Jelly. It leaves behind a treated surface that is anti-rust protected. The problem with rust, in addition to loosing some of the metal that you can never replace, is that the rust bleeds and migrates to unrusted areas. The bleeding rust is red colored and shows up as such. It stands out. The Naval Jelly gets rid of the bleeding redness and helps to prevent it returning. I think more industrial versions of Naval Jelly are available but the little plastic bottle is good enough for me. Once the redness is gone the difference is like night and day. When the rusting is just too bad then it's time for new spokes.

    Great looking gas tank. And the list of parts is growing. Have you checked out what you have for ignition yet? Really sounds like you'll have no major problems. But keep going.

    These guys here have been really nice to me and they put up with a lot of my nonsense. I kid around a lot.
    #64
  5. Wirespokes

    Wirespokes Beemerholics Anonymous

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    If you're careful, the pan gasket can be re-used. And unless the valve cover gasket gets ripped or is damaged, they always get re-used. It doesn't hurt to have a spare around - because sometimes they do get damaged. For some reason valve cover gaskets tend to get sucked in (most likely from crankcase vacuum) and then leak. I've seen it often enough that I'm beginning to think it's a good idea to seal the gasket to the head surface initially. I hate scraping stuck gasket material from mating surfaces so haven't done that yet.
    #65
  6. wirewrkr

    wirewrkr the thread-killer

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    Terry, I'm aghast!
    If it wasn't such a pain in the ass to change i could maaaybe justify attempting to reuse a pan gasket, (and I'm a cheap sonofabitch.)
    I was even straightening nails the other day!
    Valve cover gaskets, sure all the time, but pan gaskets???:lol3
    #66
  7. supershaft

    supershaft because I can

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    +1 ww! Used pan gasket?!?!? Definitely reuse valve cover gaskets whenever possible. Every time you replace one, you could be opening up a can of worms!

    I have been around shops ALL of my 50 years. I have come to the conclusion that the bigger the toolbox a wrench has the bigger the chances that he is a hack. Of course, there are exceptions but that makes the rule. We always called it chrome fever. It can get ugly!
    #67
  8. _cy_

    _cy_ Long timer

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    no way I'd re-use a pan gasket while bike is at home... but it's good to know it's re-useable on the road. make a gasket silicone does wonders when in a pinch.

    now that's a new one about the bigger the toolbox = hack :rofl

    but I see what you are getting at ... a perfect example is machine tools... just because one has a Southbend lathe doesn't you know how to operate it. now I am a hack at machining, but I've been able to machine out my needs for quite sometime. The same for welding, fully setup with Miller TIG, Lincoln pipeliner, MIG, etc. but that doesn't mean I'm able to pass coupon bend tests. but it does mean I've got access to welders and plasma cutter to fab most anything within reason.

    needless to say I will not be purchasing any luggage frames. will be constructing my own from tubular chrome-moly.

    [​IMG]

    [​IMG]
    #68
  9. _cy_

    _cy_ Long timer

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    a peek inside, down spark plug hole ... some corrosion inside, but nothing out of the ordinary for a piston sitting this long. no mechanical damage that I can see.

    will soak down with ATF to make sure everything is good and coated with a light oil before motor is run. will do a compression and leak down test soon.

    [​IMG]
    #69
  10. kbasa

    kbasa data is the new black Super Moderator

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    Can we stay on topic? If parties are unable to do so, I'm going to start handing out timeouts to all involved in the diversions. I've had to remove posts from this thread once and now I have to do it again.

    Please put your peckers back in your pants and stop wasting my time.

    Official warning shot now fired because you're pissing me off.
    #70
  11. bpeckm

    bpeckm Grin! Supporter

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    :evil
    #71
  12. _cy_

    _cy_ Long timer

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    poured two teaspoons of ATF down plug hole, then cranked over with kick starter.
    it may smoke a but on start up, but that's OK. better that then parts starting up with no lube.

    [​IMG]
    #72
  13. _cy_

    _cy_ Long timer

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    mounting new Metzler tire and IRC tube. found the tube at the Honda Dealer. Tulsa BMW dealership stocks next to nothing for airhead BMW.

    it's a bear getting that tire on the rim. very tempting to take it in to someone with a tire machine. but I need to be able to fix a tire in the middle of no where.

    [​IMG]
    #73
  14. supershaft

    supershaft because I can

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    Work the well changing tires. If you understand what that means and do it, it will be a lot easier.
    #74
  15. _cy_

    _cy_ Long timer

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    Dammit ... snake bite ... operator error

    [​IMG]
    #75
  16. squish

    squish Out of the office.

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    If that's the tire you are mounting it's going to be extra hard as that is an OLD tire.
    I've not seen a Metzler label like that in a long time.

    There's a Date code next to the DOT stamp
    To figure out the stamp you use this (two digits for week of the year plus two digits for year; or two digits for week of the year plus one digit for year for tires made prior to 2000).

    But if that tire label indicates that Metzler is located in Washington state that it's more then 20 years old
    #76
  17. supershaft

    supershaft because I can

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    Some bike show guy might pay big bucks for it. More if you get some fingernail clippers and clip the mold nipples off so it looks like is brand new yet somehow ridden.
    #77
  18. _cy_

    _cy_ Long timer

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    that tire is 20+ years old, but was wrapped up, sealed pretty good. tire is not hard at all, still pliable exactly like a new tire. would not have problems riding that tire anywhere. the same front tire I took off with 95% of thread intact is hard, way too hard to ride safely.

    was thinking of some collector would dearly love to have this tire as I was cutting off the original wrappings.
    #78
  19. _cy_

    _cy_ Long timer

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    comments about tire hardness concerned me... so pulled out a Shore Durometer, which verified tire's elasticity.

    plans were use this tire temporarily until I order some new style Metzlers. maybe this tire does need to stay in new condition for a collector.
    #79
  20. wirewrkr

    wirewrkr the thread-killer

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    You're not really gonna run that tire are you?
    Yikes!
    #80