The /5 phoenix project

Discussion in 'Airheads' started by Captain Yesterday, Sep 22, 2012.

  1. Captain Yesterday

    Captain Yesterday Been here awhile

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    Oddometer:
    152
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    Update

    Before
    [​IMG]

    After
    [​IMG]

    Fork time

    [​IMG]

    Little bit of scoring

    [​IMG]

    I like how one fork had ATF oil and the other one looked like it had motor oil in it

    Compare and contrast

    [​IMG]

    This was making a mess in the forks

    [​IMG]

    The fork rod with the motor oil looking oil in the fork was a bit sized, did not move to easily.

    [​IMG]

    All done good to go :freaky

    [​IMG]

    Next up the wheels, Whats all that crap? Also someone shoot the guy to designed the wheel bearings set up on these bikes

    [​IMG]

    Maybe it might be rolling by the end of next week :evil
    #41
  2. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

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    Ya see, now this is how you resurrect an airhead!
    #42
  3. disston

    disston ShadeTreeExpert

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    Looks like some kind of clay. Great pictures BTW. And not to deny your right to have a different opinion but I like the design of the wheel bearings. Maybe I just don't know any better? The /5 does have the 14mm axle I think.
    #43
  4. Captain Yesterday

    Captain Yesterday Been here awhile

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    Still trying to figure out how to clean up the motor? I have a blast cabinet and I've tried on a small spot on the starter cover aluminum oxide, glass beads and a XL soda "aka baking soda" none have given me the results I'm looking for. I think I may need to paint the engine and trans. Will 550 degree engine paint work on the heads and jugs with out burring off?

    Also, rear shocks? Ikons or Bob's re-po shocks? Which ones are softer? California roads suck so softer the better.
    #44
  5. Captain Yesterday

    Captain Yesterday Been here awhile

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    Before and after on the wheels

    [​IMG]

    Piston is finished, it was seized badly :cry The cylinders are at the machine shop getting honed and then checked. Hopefully all the cylinders need is to be honed

    [​IMG]


    It's a roller :clap

    [​IMG]

    O the humanity !!!!!!!!!!!!!!!!!!!


    [​IMG]
    #45
  6. brocktoon

    brocktoon Been here awhile

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    Regarding the wheels: before and after what !?
    #46
  7. zenduddhist

    zenduddhist Been here awhile

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    Coming along nicely...
    #47
  8. LanceR75

    LanceR75 Adventurer

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    How did you get those fork bottoms clean? Painted, powder coated?
    #48
  9. Captain Yesterday

    Captain Yesterday Been here awhile

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    Cleaned rim, new spokes, painted hubs, and checked bearings

    Brass wire wheel, Al oxide blasted in a blast cabinet, hot soap and water, and paint.
    #49
  10. gfx

    gfx gfx

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    Dude, tell me about it. :cry
    #50
  11. Captain Yesterday

    Captain Yesterday Been here awhile

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    Left side rod bearings

    [​IMG]

    Right side rod bearings

    [​IMG]

    Housing

    [​IMG]

    [​IMG]

    Crank

    [​IMG]


    [​IMG]

    [​IMG]

    Rear main

    [​IMG]

    That engine sprocket did not want to come off.

    [​IMG]

    What the hell is up with this myth that BMW's easy to work on yeah right :huh Taking this engine apart was a total pain in the ass. You need a "special" tool for just about everything, and nothing came apart willingly.

    Only question is on the right side rod bearing. It's not smooth enough to where I feel comfortable reinstalling it. So do I replace the the rod bearing and leave the crank alone or do I take the crank to a chop and have them grind it down to match the new road bearing? The crank feels fine to the touch.

    The front main looks ok but the back is boarder line as well as the thrust washers bearings.

    decision decisions do I replace all the bearings or just the rod bearing decision decisions I guess it's up to how much more money I want to dump into this thing.

    :ear:ear:ear
    #51
  12. halflive

    halflive Been here awhile

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    All your bearings seem to have some scoring. I would replace all of them. Never grind an airhead crank, they tend to break if its done. There are different theories why, but the rule is don't.
    Just buy new standard big end bearings and leave the crank standard.
    #52
  13. FR700

    FR700 Heckler ™©®

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    Right hand rod shows signs of either dirty assembly or something got past the filter.

    Buying standard bearings is great ... if the journals still measure out at stock spec's and the mains can be re-claimed by linishing ... and no oval'ing of the big end.

    Cranks can be ground ... the trick is by who and whether they get the correct radius :evil




    .
    #53
  14. disston

    disston ShadeTreeExpert

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    The crank big end bearings are not really expensive. I'm not going to look it up but I have seen a couple little pieces of rubber cost more. Not uncommon for there to be a little scoring. Check for grooves in the corresponding place of the crank. I have put car motors together with a little scoring in the crank but these were fleet vehicles. On an Airhead I might want to find a better crank if it looks bad. But I also would probably use a crank that had a couple small scratches.

    I have mostly heard bad stories about regrinding Airhead cranks. Not only is the radius in the edges critical but the hardening of the metal is not easy to do. Some of the best say to get another crank. And here's the thing, any where in the World right now for any Airhead vintage engine needed an extra, spare, used crank can be found. They are cheap. Maybe in 50 years it will be a different story
    #54
  15. brocktoon

    brocktoon Been here awhile

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    You say the journals are smooth to the touch. Does your fingernail catch in the grooves?

    You've already gotten two opinions on whether or not crankshaft journals can be ground. Here's a third from Airhead guru Oak Okleshen:

    In short, you can grind it but it won't last long and you'll be back in the same position soon enough. Used cranks in good condition are not impossible to get ahold of through the usual Airhead parts folk.

    Is there another comparable bike you can think of that doesn't require special tools to pull apart to the bare crankcase? Not being sarcastic, I'd genuinely like to know. Did you pick up an engine disassembly kit from Cycleworks? It has pretty much everything you need to tear it apart just a few good grunts -- except the con-rod bolt removal tool, which is available from Napa.
    #55
  16. FR700

    FR700 Heckler ™©®

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    Seriously , an early K series 2 valve bm'.


    .
    #56
  17. FR700

    FR700 Heckler ™©®

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    Nothing to stop you getting the crank re-nitrided , happens all the time. As I said , the trick is by who and if they understand ...

    Am I talking out my ass ? ... a widdle pic'


    [​IMG]
    #57
  18. brocktoon

    brocktoon Been here awhile

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    Huh. Wonder why Airheads got the "easy to work on" reputation while K series were overlooked?

    What's re-nitriding run?
    #58
  19. Captain Yesterday

    Captain Yesterday Been here awhile

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    No I didn't pick up the kit, I've been borrowing the BMW specific tools, or making my own. I've gone through a couple of engines over the past couple of years couple of bmw car engines, air cooled porsche, toyota 4 cylinder truck, and a couple motocross 2 stroke engines. Motocross 2 stroke engines are so easy to completely dissemble and rebuild.

    As for the crank, the only reason why I asked about re-grinding it to match the new bearings is that, that is what I have done in the past for other car engines. As for this crank it feels fine running my finger and nail along any part of the crank. The only areas that don't feel ok is one of the rod bearings and the thrust washer bearings on the back part of the main. The mains on both ends feel ok, but the back one looks questionable but feels ok. As for the rod bearing that needs to be replaced and the scoring is in a different location from where the journal is. So I'm fairly sure the crank is ok. The motor only has 58,xxx miles on it.

    I think since I'm this far I'll just replace all the bearings, that way the bottom end will be good to go for a long long time hopefully.


    Thanks for the input :freaky
    #59
  20. crazydrummerdude

    crazydrummerdude Wacky Bongo Boy

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    Looks kinda like my Model A crank. What's the runout on the lathe?
    #60