1971 r50/5 sat for a decade - re starting

Discussion in 'Airheads' started by madtownadv, Aug 13, 2021.

  1. Plaka

    Plaka Brevis illi vita est

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    do not omit replacing the oil filter. your initial start up will be flushing the system. thus a cheapo aftermarket filter (HiFlo Filtro, etc) that you can toss after a few minutes running.
    #41
  2. Texer

    Texer Been here awhile Supporter

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    Plus with that year I don’t believe you need to worry about any o-ring with the filter.
    #42
  3. Plaka

    Plaka Brevis illi vita est

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    the two o-rings are attached to the filter. one should check that an inner one has not been left in the block. the outer cover gets a new gasket...some other time. get it running.
    #43
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  4. madtownadv

    madtownadv Adventurer

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    Tank after 1 1/2 days of evaporust....

    Pre soaking

    tank rust 2.jpg

    day and 1/2

    Tank Rust 2nd day.jpg

    Thoughts??
    #44
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  5. Plaka

    Plaka Brevis illi vita est

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    I think you can't see where it counts.
    #45
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  6. CA-Cincinnatus

    CA-Cincinnatus Semi-retired GI-Bill student, husband, GSD-host Supporter

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    What @Plaka said - you can't see what you need to see. You need to be able to see the bottom of the tank at the seams where water has probably created rust. That rust may or may not be enough to trash the tank entirely. If there are bubbles under the paint along the bottom of the tank, that's rust that's eaten through the metal and will be difficult, if not impossible to repair, hence a new tank may be required to be road-worthy.

    If it's going to end up being a decorative piece of moto-art for the lady, that's fine, the tank won't get gas and will look pretty in the barn, etc. If it's going to be a runner, then the tank MUST BE safe to fill with gas, and thus replaced.

    If there's NO bubbling of the paint anywhere along the bottom, you've lucked out and have solid steel, to varying degrees. Get all the rust out, meaning completely rust-free, otherwise it'll continue to rust. Seal it with POR-15 or whatever you choose, but again, there can't be any rust anywhere in the tank.
    #46
  7. r60man

    r60man Long timer

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    Seems to me that you are waiting on the gas tank to try to start the bike. A gas can with a hose could get you past that. Those old tanks had a way of rusting on the bottom that you wouldn't know it because the paint still looked intact. I had a 75 /6 with a tank that developed pinholes on the front edge, down at the seem. Check that area very carefully and hope for the best.
    #47
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  8. Plaka

    Plaka Brevis illi vita est

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    Rusted through tanks can be repaired but without some metal working skills it can be cost prohibitive.
    #48
  9. Pokie

    Pokie Just plain Pokie.

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    If you use Evaporust, buy enough to fill the tank completely. If you just put in a gallon and leave the tank in different positions, you need good air flow. If the tank is closed, the Evaporust will clean where it is in contact only, the rest of the tank will start to rust again from the condensation given off by the Evaporust process. This is why I like the vinegar process, it's fairly cheap to fill the tank completely.

    The tank will never look like new again no matter what you do. Getting out most of the rust and crap is about all you can effectively do. Once the tank is dry inside, re-fit it and run external fuel filters.
    #49
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  10. madtownadv

    madtownadv Adventurer

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    Thanks everyone.... the petcock came today. I installed it, put some gas in the tank. It started right up and I drove it back to my neighbors :-)
    #50
  11. WooPig

    WooPig Redundant Supporter

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    Well done!
    I suppose… you’ve gently hinted that you’d give it a good home and regular exercise if they ever decide to part with it?

    Good job. Congrats!
    #51
  12. Disston

    Disston ShadeTreeExpert Supporter

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    Now, if they are going to just park it again for a number of years, the gas has to be drained from the tank and the carbs.

    There are additives that can be used to preserve the integrity of the gas but I don't have any experience with these.
    #52
  13. madtownadv

    madtownadv Adventurer

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    She is already driving it. I'll help her put some miles on it and run some gas through it. It does still need some love....

    Hopefully, this is a real re-birth for it :-)

    I have a video of me starting it, but don't know how to upload it :-(
    #53
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  14. Disston

    Disston ShadeTreeExpert Supporter

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    Up load your video to You Tube then post the link here.
    #54
  15. madtownadv

    madtownadv Adventurer

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    #55
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  16. Bluethumb

    Bluethumb Been here awhile

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    Nice!
    #56
  17. Plaka

    Plaka Brevis illi vita est

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    I just had a problem with my air compressor. been sitting 4+ years with nasty old gas in the tank and carb. Much work to get the old gas out then a half tank of fresh stuff with techron and seafoam. A few hours coaxing the cleaning mix through the carb running it in bursts with starting fluid then waiting a half hour then another burst, etc. Then it fired up and I idled the cleaning mix through for another half hour. Fires on the first or second pull now.
    #57
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  18. Bluethumb

    Bluethumb Been here awhile

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    This is an Airhead tread, why are you posting about an air compressor that you were too lazy or stupid to maintain and why are you croaking about how you can start it now? Just to steal attention away?

    (oh darn, somehow I channeled Plaka, don’t know what came over me)
    #58
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  19. tlub

    tlub Long timer Supporter

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    I spent a few hours with him, working on the bike on Tuesday. It was really clean under the front cover; points were good, timing spot on. After we retorqued the heads, the valves were close. Maybe one or two thousandths (inch) loose, but all were about the same, we adjusted them all. We have a list of things we are working through. Overall it seems pretty solid, but needs filters, fork gaiters and probably seals, and all the tapered bearings need grease, and the carbs need at least adjusting. And the tires are frightfully cracked and aged. Riding it just around the block gave an overall positive impression to me. Except for the tank, it is remarkably free of corrosion, and seems to have been well maintained. From what I could see of the tank, the Evaporust worked well. Some liner remains; we may do a POR-15 treatment. The steering head bearings are good.
    We are working on items on the 'list'. The goal is a rideable, safe machine (which it isn't now), not a restoration.
    My next few weekends are filled with BMW rallies, and the Slimey Crud. We might get to it on evenings. I'm retired; he isn't.
    The other thing, of course, is that after sitting all this time, I expect that once it's ridden a bit, every single seal in the engine and transmission will start leaking, requiring a fairly complete teardown to replace them.
    #59
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  20. Beemerguru

    Beemerguru Beemerguru...G/S guy

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    Start with old fashioned dino oil for the first few hundred miles and give those old seals some time to swell back up..you may get lucky
    #60