#4 - R90S Powered /2 Conversion Period Hot-Rod

Discussion in 'Airheads' started by Solo Lobo, Jun 17, 2020.

  1. Pokie

    Pokie Just plain Pokie.

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    "That really is nice paint."

    Mine will never look that nice!
  2. Solo Lobo

    Solo Lobo airhead or nothing Supporter

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    Here you go!

    4.00 X 18
    .
    [​IMG]

    3.50 x 18

    [​IMG]
  3. tennessee thumper

    tennessee thumper Long timer Supporter

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    Nailed it w/ the new tire. Much more balanced, by my eye anyway.

    You gotta be pumped with the visual presentation here, good work.
    Solo Lobo likes this.
  4. nmalozzi

    nmalozzi airheaded

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    Looks FANTASTIC. Looks like I know what size I'll be going with.
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  5. edray

    edray cascadian

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    Art baby!,,, kudos, sir
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  6. Solo Lobo

    Solo Lobo airhead or nothing Supporter

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    So rear main seal changed, although there was no real hard evidence it was the source of the leak.
    A bit of hylomar added to the flywheel bolt threads, where the locating pins meet the flywheel and where the flywheel meets the crank and no change to the leak.

    this is after about 3 miles, perhaps the seal needs more miles to bed in more/better? Or the rear main isn’t the leak at all

    didn’t pull and reseal the oil pump cover, and that could be the source… didn’t see any evidence there on the top of sides but the bottom edge wasn’t checked thoroughly.

    next steps? Dunno, maybe more miles, weather permitting, before I take things to pieces again

    [​IMG]
  7. bmwrench

    bmwrench Long timer Supporter

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    Are you using the OEM Teflon seal?
  8. Solo Lobo

    Solo Lobo airhead or nothing Supporter

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    OEM seal, straight from my dealership.

    not that it adds much, but here are some shots from my boroscope

    [​IMG]


    [​IMG]

    [​IMG]
  9. tennessee thumper

    tennessee thumper Long timer Supporter

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    SL,

    Feel your frustration and sorry this is an issue.

    Assuming you go in there again, I might suggest this MO:

    clean the back of the block, make it bone dry, sprinkle with baby powder---put the carbs, flywheel back on and run it for a minute so you can pinpoint the source of the leak.
  10. Pokie

    Pokie Just plain Pokie.

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    Any chance it's transmission oil?
  11. tennessee thumper

    tennessee thumper Long timer Supporter

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    Poke, that was my first question, too. I think he ruled that out?

    I had a similar issue after RMS install on my S and assumed there was an issue there. Turns out in my case it was the output shaft seal.
  12. Solo Lobo

    Solo Lobo airhead or nothing Supporter

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    Engine oil for certain....

    Since I saw no evidence of the leak on the sides and top of the oil pump cover I am kind of thinking the leak may be from the bottom of the oil pump cover.

    In truth I didn't have any hylomar at the time and sealed with with plain old gasket sealant... totally possible that it wasn't clean enough, the o-riung slipped, or whatever.

    Guess I will have to pull the flywheel again, reseal the pump cover with actual hylomar, and dust the area with powder and retest again.
  13. bpw

    bpw Been here awhile

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    Since we are talking tires, my /2 uses the same 18/19 wheel combo as you and I recently put a set of Perreli Scorpion Trail on in the 100/90-18 and 100/90-19 sizes.

    Not quite “period” looking, but they ride nice, do well on dirt roads and got rid of the floppy steering I had with the 19” front wheel and vintage type tires.

    The bike is way, way nicer on grooved pavement now too.
  14. tennessee thumper

    tennessee thumper Long timer Supporter

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    I've not done it but....running the engine for a bit, with the trans out might save you another teardown, assuming (hopefully not) the leak is persistent or even better----offer the comforting notion that the leak has been buttoned up before you reassemble everything.
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  15. Disston

    Disston ShadeTreeExpert Supporter

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    I have no doubt that you did do it right but in the interest of thouroness I'll say it anyway: The currant teflon seal goes in dry.

    I do things different than anybody else here so I'll tell you. I carry extra oil. If I have an oil usage issue I have extra oil. Problem will get attention when time and my disposition allows.My method has extra room in it for thinking about it which I often find helpful.

    Just ride.
  16. bmwrench

    bmwrench Long timer Supporter

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    No sealant should be needed on the pump cover. If the pressure gets by the o-ring, it'll blow the sealant out.
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  17. Solo Lobo

    Solo Lobo airhead or nothing Supporter

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    I wish it was that simple for me... I can't live with oil leaks on anything I own... and that is a real fight on the 180,000+ mile Ranger that is the fleet


    That may be the issue, and this is the only airhead I have ever added sealant to the oil pump cover. Read that "tip" somewhere recently and though it couldn't hurt...


    So my plan is to pull the flywheel, remove the oil pump cover and check it over - reinstall with no sealant.

    I'll dust the back of the case there with something, and try to run the motor without the transmission and see what happens.
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  18. Disston

    Disston ShadeTreeExpert Supporter

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  19. Solo Lobo

    Solo Lobo airhead or nothing Supporter

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    We are having a huge power outage here, so what better time to go take the /2 apart?

    [​IMG]


    given this evidence , I’d say the leak is the dowel pins.

    I used almost zero hylomar on them and didn’t clean the pins or the holes…

    I’ll clean it all, use a reasonable amount of hylomar and also clean the oil pump door this week and see what happens next

    [​IMG]
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  20. bmwrench

    bmwrench Long timer Supporter

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    Yes, I'd say they're your culprit.
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