Add me to the cracked fuel tank list

Discussion in 'Parallel Universe' started by lepoer, Sep 29, 2010.

  1. The Griz

    The Griz Long timer

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    I don't know about that, man. Mine's cracked twice now. Once with the charcoal canister installed and once without it instaled. My opinion is that the charcoal canister has nothing to do with it. It's just shotty plastic molding: horribly formulated plastic and too thin.
    #21
  2. Firefight911

    Firefight911 Been here awhile

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    Hi, my name is fishy. Glad to meet you!

    As to your point #3, my replacement tank is a confirmed, verified, obviously different, had to wait for the new one, had corporate involved redesigned tank and........wait for it........here it comes......not quite.......yep, you guessed it! Mine is cracked AGAIN.

    Every F on the dealer floor near me has a cracked tank. Every one! (This is up until the 2011 models showed up. I have not seen any cracks on the newest ones.....YET.)

    Just sayin'!
    #22
  3. EnderTheX

    EnderTheX Dirt Rider

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    Hmmmmmm....

    OK, here is another factor this points to:

    Faulty process parameters for fabrication!

    When you think about how the crack looks this could be a huge factor. The crack looks bubbly and irregular also as if the material was "falling apart" instead of being pulled apart. There are also no stress marks around the crack that I noticed...

    Weird and interesting :D
    #23
  4. JRWooden

    JRWooden Long timer

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    Griz:
    Did you read the fine print in the poll :wink:
    Have you removed your pressure check-valve? If so that would be an interesting piece of information!

    I'm not asserting its the CANISTER it's self, but the canister "system".
    The canister system has a checkvalve in it that allows the fuel tank to build ~5psi of positive pressure. The rest of the world's F800GS never build any significant pressure. I think this is a key factor. (I could be wrong...)

    EnderTheX & Griz:

    I am a mechanical/mfg engineer as well.
    I do not dispute any of your assertions (well at least I don't think I do :freaky)

    I do think the radius is too sharp, and that over time the non-USA bikes might crack as well. Some folks with the new Rev #2 tank (more gentle radius) have had tanks crack as well.

    Materials selection, wall thickness, wall thickness transitions, location of mold injection ports/knit lines, and ... maybe process problems ???

    Along the crack line of my tank there appear to be some small bubbles which might lead me to beleive injection temperatures were too high, perhaps there was too much moisture in material, or the cooling rates were non-uniform.

    I'm not saying the ONLY factor is the pressure checkvalve in the canister system I'm just saying its an aggravating factor.

    The reason I haven't had mine replaced is that it just doesn't piss me off that badly ... I think (hope) that BMW has called in some experts in plastic molding process by now and is working on Rev. #3 of the tank - so I intend to wait till near the end of my 3-yr warranty and get a new tank then ... hopefully it will be rev #3 if not than I'll have 2-yr extension on the warranty and by then have a rev #3 tank.

    Maybe I'm just talking out my a$$...
    It's happened before... :lol3
    #24
  5. The Griz

    The Griz Long timer

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    Either way, good observations and work, JR. I'm glad you're in the trenches trying to get some answers on this one.:clap
    #25
  6. santafe carlos

    santafe carlos n00b

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    Just back on the ADV board after not visiting since August. Boy I am glad I checked in. Sure enough went out to the garage today and found this crack:eek1
    #26
  7. Emperor Norton

    Emperor Norton Kilroy was here

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    Okay I have a 650 and a stupid question. If this issue was just the raidus (or angle? dont kill me Im 1337 not a ME) why do the new design tanks also exhibit cracking?

    And mayhaps Ive missed this, but is this exlusive to the 800 or is it also seen on the 650? (if it isnt then WTF over).
    #27
  8. EnderTheX

    EnderTheX Dirt Rider

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    Yeah... you pretty much missed most of this thread and the other threads covering this (and you might want to try spell check too).

    Basically no one knows what is truly going on except the new design with the new radius is holding for most people and the first gen tanks are almost all cracking, you can check yours in 5 seconds. :deal
    #28
  9. Uncle Pollo

    Uncle Pollo Long timer

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    Take it to your dealer ...
    #29
  10. Motorfiets

    Motorfiets Long timer

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    whats year is the new gen? :ear
    #30
  11. EnderTheX

    EnderTheX Dirt Rider

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    Most probably the 2011s have new gens but bikes built for 2011 may have been built late 10 so I wouldn't be counting your chickens until the 2012 bikes. Basically everyone should keep an eye on cracking and take it in for warranty if it shows signs... simple :D
    #31
  12. Motorfiets

    Motorfiets Long timer

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    aight thank you sir :freaky
    #32
  13. NVTS

    NVTS Are you ennen oh eff tee

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    Just got my new tanked F8 back today. Drove 4 hours roundtrip to find it stinking of fuel upon arrival at home. Fuel is leaking out of the gas cap area. I thought they might have overfilled it (though I have done this and never had a leak this bad) but upon inspection I found...
    [​IMG]
    #33
  14. EnderTheX

    EnderTheX Dirt Rider

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    Is that a crack in the filler cap ring above that bolt? Is that where it is leaking from?
    #34
  15. NVTS

    NVTS Are you ennen oh eff tee

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    The leak is coming from that general direction. I wonder if it is part of a larger seal. For reference; the bike was hauled home in the back of my truck completely vertical and I noticed the leak before unstrapping/unloading. NVTS
    #35
  16. Off Road Ryder

    Off Road Ryder Long timer

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    This is an interesting thread. Do you guys think there would be a market for a carbon Fiber Tank ? then it might as well be of higher capacity.
    #36
  17. Motorfiets

    Motorfiets Long timer

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    a little birdie told me there is another tank coming... not touratech.... no word set in stone yet. :evil
    #37
  18. ebrabaek

    ebrabaek Long timer

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    :ear:ear....:D

    :thumb:thumb

    Erling
    #38
  19. NVTS

    NVTS Are you ennen oh eff tee

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    I took the F8 for a short ride Sunday and didn't experience any more leaking fuel. This means I can ride the bike 2 hours south to get the piece repaired instead of truckin it!:D
    #39
  20. LukasM

    LukasM Long timer

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    Safari? X-Tank?

    Give us a hint, will ya please? :ear
    #40