The secret to replacing the Poly-V belt (1150GS)??

Discussion in 'GS Boxers' started by Norsman, Sep 7, 2009.

  1. AntonLargiader

    AntonLargiader Long timer

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    Partial reprint here: http://www.bmwra.org/otl/belts/
    There's more on ELAST in the rest of the article. I'll probably put the rest online at some point but I don't know when.

    I believe it. Probably will work fine; it's just not the system that BMW intended.
    #21
  2. Anorak

    Anorak Woolf Barnato

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    The best way to tell is to take the front cover off and look at the alternator pulley. If it has the black plastic cap over the shaft, it uses the "elast" belt.
    #22
  3. Norsman

    Norsman ...a GSophile

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    Now I'm really confused. I have that black plastic cap over the shaft of the top pulley. But, the following belt will NOT physically fit at all:

    ELAST: 4PK592, '04-on Oilheads and most Hexheads, BMW part 12 31 7 681 841

    This belt does however:

    Poly V: 4PK611, BMW part 12 31 1 341 779
    #23
  4. Anorak

    Anorak Woolf Barnato

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    Norseman, the elast belt has to be stretched to fit on the bike even on the 1150 with the adjusment slackened. You need to rotate the pulleys while easing it on.
    #24
  5. Norsman

    Norsman ...a GSophile

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    Does anyone have specific printed instructions on how to install the "stretchy" 841 and how to adjust the tensioner bolt.

    I tried rotating it on... not a chance.
    #25
  6. Jim Moore

    Jim Moore Long timer

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    :clap :freaky
    #26
  7. AntonLargiader

    AntonLargiader Long timer

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    You don't adjust that bolt with the ELAST system, all you do is tighten it after the alternator is positioned.

    I just put the rest of the article online; it might clarify things.

    http://www.bmwra.org/otl/belts/
    #27
  8. SourKraut

    SourKraut Long timer

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    I've thanked you before and I'm doing it again. :thumbup

    I tensioned mine by loosening the three bolts and prying before tightening, 20K miles ago.... :hide
    #28
  9. Norsman

    Norsman ...a GSophile

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    Okay, despite what everyone is saying here, and despite the great article about the ELAST belt, my ELAST (841) belt will not fit or go on; absolutely not.

    According to all the pics, I DO have the ELAST system, but no way is it going on.

    As noted earlier, I broke the tensioning bolt and I got tired of waiting for a new one to come in the mail (I live about 3+ hours from a dealer), so I superglued it together (the bolt), put the 622mm belt on and raised the alternator as high and as tight as I could get it and fastened down all the bolts.

    The belt could barely bend 90 degrees and felt pretty tight. I put everything together... alternator plate, crash bars, and tank back on and guess what?

    There is a slight burning smell?

    Do you think it is slipping? If it is, will it damage anything? The bike runs fine.
    #29
  10. AntonLargiader

    AntonLargiader Long timer

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    I'd look for a second set of eyes. Is there any sort of local club activity, or an independent BMW guy nearby?
    #30
  11. Norsman

    Norsman ...a GSophile

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    Update: I didn't get the belt tight enough with my super glue hack job; the bike's headlights stutter when I accelerate quickly and the bike almost stalls at the same time.

    Oh well, I guess I'll wait for the tensioner bolt to arrive in the mail. In the meantime, I'll talk to the closest dealer about the ELAST belt thing, I'm still an unbeliever.

    On top of all this, I stranded myself today with a faulty kill switch. Arrrg. :eek1
    #31
  12. Kokopelli

    Kokopelli Yeah, right!

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    My 1150 uses the 611 belt. However, I ordered the wrong belt and ended up with a 595 belt. I just put it onto the pulleys. It was hard to get on. The adjustment is completely slacked off, but I can only just turn the belt by 90 degrees with my fingers. Should I take it off again to and get the correct belt, or will this be fine? I don't want to ruin the bearings.
    #32
  13. Norsman

    Norsman ...a GSophile

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    If you can twist the belt 90 degrees, it's probably okay. But, if it where me, I'd try to get the right belt in there.
    #33
  14. Kokopelli

    Kokopelli Yeah, right!

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    I put the old one back on again and will carry the new one as a spare, until I can get the correct size.
    #34
  15. PETDOC

    PETDOC Long timer

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    Norsman, do you know the exact build date on your GS? If not, here is a web site (http://www.bmwarchiv.de/vin/bmw-vin-decoder.html) which will give it to you if you input the VIN.
    I know with my '04 1150 GS, built before 7/1/03 the belt is different than my buddy's '04 which was built after 7/1/03
    #35
  16. Norsman

    Norsman ...a GSophile

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    Thanks for that link!
    #36
  17. CrustyAPO

    CrustyAPO Been here awhile

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    #37
  18. Ron from BC

    Ron from BC Long timer

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    That was disappointing to hear the a dealer had provided the wrong belt. Don't they all use the BMW ETK? They should be able to enter your VIN and get the 'right' part.
    #38
  19. Anorak

    Anorak Woolf Barnato

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    Okay, ready for this? Read page three for the complicated part
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    #39
  20. Norsman

    Norsman ...a GSophile

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    The plot thickens.
    #40