Replacement for cracked F8 fuel tank

Discussion in 'Parallel Universe' started by BykMyk, Mar 17, 2010.

  1. ebrabaek

    ebrabaek Long timer

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    Well... In that case they don't know $h!^..... as there are no contact between the liquids, and the outer shell. Granted.... the gasses will permeate through, which is why you don't put stickers on any composite tank, but..... Ethanol does nothing to the poly ...... Tanks.
    #21
  2. EPMD

    EPMD Been here awhile

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    First off, I can't speak to the effects of ethanol on plastic tanks with any authority because I am not a chemist.

    But from how certain you are that it has no ill effect, I'm betting you are, so thanks for the info smart guy.

    Second, it does make sense conceptually that ethanol in the main tank could cause swelling that could cause cracks in the weak points of the outer shell.

    :puke1
    #22
  3. runnin4melife

    runnin4melife Been here awhile

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    :rofl I am from Missouri which adds ethanol to fuel (10% or higher) and I have had no issue with my tank... I am now in MD where ethanol isn't added where I purchase gas and I have no problem either.

    Ethyl alcohol, or ethanol is a pretty gnarly solvent, but the noted trend with these tanks does not lend itself to ethanol as the culprit. Otherwise my BMW would be leaking every where and my tank is just fine as I pulled the whole thing off just the other day to make something.
    #23
  4. mbonadio

    mbonadio Adventurer

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    My brand new '13 F700GS tank cracked on both sides within 2 weeks of purchase and after just 2 tanks of gas.... I'm pretty disappointed. More disappointed that I spent all this money on something that's been known bad for 2-3 years and with no signs of a permanent fix. So now, I have to live with the prospect that after my warranty period I'll have a cracked tank for the rest of it's life! I'm not too happy about it right now.... I'll keep my fingers crossed that something changes in the coming year.

    But given how quickly my brand new bike developed issues, I sure do wonder!
    #24
  5. ebrabaek

    ebrabaek Long timer

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    I stand by my earlier statement.....
    #25
  6. itsatdm

    itsatdm Long timer

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    I am not even sure it is dual wall. The liner is certainly different texture than the outside, but peering into the tank it may be nothing more than a liner of some type. Maybe when some ones fuel pump goes out they could check on that for me.:rofl

    Worry about when it happens to you, because it did not happen to all. BMW did make a change in the curvature of the tank, supposedly to solve the problem. They held off on putting them out: IE design time.

    The result was in our rush to get another tank some got old stock. Maybe they have some left over in the warehouse.

    Nobody's tank leaked. The warranty on the bike is 3 years and if you wait to the end, you get 2 more years of parts warranty.
    #26
  7. HighFive

    HighFive Never Tap-Out

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    Wonder if any of the late model Husky tanks (beneath the seat) have ever cracked? Seems reasonable to assume they are made by same production facility.....look quite similar in material on the outside.

    I'm blaming the Engineers. Takes one to know one. Just sayin

    HF :jose
    #27
  8. itsatdm

    itsatdm Long timer

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    I am blaming the accountants and making a list.:evil Some where stamped on one of the plastics it says "made in Taiwan" I am blaming them too.
    #28
  9. JRWooden

    JRWooden Long timer

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    That's where I'm at now ... when I get my replacement at the 5-year mark ... it would "seem" that I should get another 2-year warranty on the new (2nd) replacement ... anybody know if that's true?
    #29
  10. Pomo

    Pomo gonzo

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    I'm having a tank-ectomy done on Friday. If I don't get kicked out of the "kitchen" I'll try to peek over their shoulders and see what it looks like inside.
    #30
  11. JRWooden

    JRWooden Long timer

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    Get them to cut it in half! :lol3
    #31
  12. Pomo

    Pomo gonzo

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    Definitely two pieces, an inner bladder and the outer shell. You can remove the gas cap and see it pretty clearly there.
    #32
  13. JGoody

    JGoody Been here awhile

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    After reading the thread I'm still trying to understand the cause. If there's a bladder then there is no contact with fuel to the outer shell so it's not the Ducati problem where the ethanol causes the tank to develop bulges. If it's expansion then it would be easy to reduce the volume of the bladder or adjust the shape to allow a little clearance. If it's stress related fracture due to vibration etc then why wouldn't it be beefed up a bit in the areas where they crack? So what's going on here?
    #33
  14. ebrabaek

    ebrabaek Long timer

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    I personally think that it is in the casting of the outer case. If temps and or mix is not right, the areas that will give in first, are the areas of stress....... Which is the extreme angles. I have not heard of any other cracking except those. Hard angles. Why some do and some don't , only explanation I can come up with is just inconsistency in production. I though for sure that cooking my tank in the hot desert southwest would have killed mine. But nothing. Got mine back in 2009. Many in ethanol areas are reporting no cracking. So it is not that either. There are no patterns, and with such, I claim inconsistent casting.
    #34
  15. COracer

    COracer Adventurer

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    So I'm buying an '09 with the cracks, it is out of the three year warranty. Does anyone know if indeed this is covered for the 5 year fuel/emissions warranty? Has anyone reported leakage or is this strictly cosmetic?

    Anxiously awaiting the cutaway of one...:ear
    #35
  16. ebrabaek

    ebrabaek Long timer

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    I have heard of many who got theirs replaced as " good faith " from BMW. Have you tried to ask your local dealer.... Or.... is this the one your buying from...???:D
    #36
  17. Pomo

    Pomo gonzo

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    I had mine replaced last week, just a little under 6 months past the three year warranty. I got it done "good faith", but I'm also the original owner of the bike. The guy I talked to at the dealer said that was definitely a factor in getting not only the cost of parts covered, but also the labor. You might get lucky on parts if you have a nice dealer, but based on what I heard it would be somewhat surprising if they covered the labor.

    I don't know if I'd classify it as it "strictly" cosmetic, it may indeed weaken the fuel tank. But the cracks will not instantly cause fuel leaks.

    I don't have a cutaway, but here are pictures of where the fuel pump and filler neck are mounted.

    [​IMG]

    [​IMG]
    #37
  18. COracer

    COracer Adventurer

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    Thanks for the info gents, picking it up tomorrow from a private party. Bike has just under 12k on it and he had the 12k service done at a local dealer in November. While he hadn't noticed it and they didn't tell him about it, the RO has tech notes that the tank is cracking and he was upfront and told me about it when I looked at the bike.

    I will probably try to get it replaced even though it seems it may happen again from what everyone is saying. Worst case I see a few on forums and Ebay for sale with no cracks from parted bikes, I wouldn't mind doing it myself, need to learn the ins and outs of the bike eventually.
    #38
  19. Pomo

    Pomo gonzo

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    There's some kind of special tool used to remove/install the fuel pump. You could probably rig something up though.

    Edit: the tank comes off pretty easily, but you have to remove the subframe from the bike as the tank slides over the front of it. Makes sense when you see it.
    #39
  20. LukasM

    LukasM Long timer

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    I have swapped many subframes and tanks, no special tools needed. The ring for the fuel pump can be unscrewed by tapping it with a screwdriver/chisel and a small hammer.
    #40