how to remove jet needles

Discussion in 'Airheads' started by CanadaBiker, Apr 2, 2013.

  1. CanadaBiker

    CanadaBiker Been here awhile

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    I want to replace the jet needle (nozzle needle in the fiche) but I can't figure out how to remove them. My manual says something about push and twist, but I can't figure it out. The fiche shows clips and toothed rings, but as I understand it, not all models use those clips?

    Also, once I get them out, it must be challenging to get them back in at the right groove? Any advice?

    Thanks
    #1
  2. Hookalatch

    Hookalatch Born Under Bad Sign

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    Twist the needle 90 degrees or 1/4 turn and gently push up on the needle. Continue the 90 degree rotation until the needle comes out. Count the number of turn to determine what groove it was in. You can also measure how far the needles stick out to get the same location when they are replaced. It becomes pretty obvious how that works when you actually see the needle.

    Chuck
    #2
  3. Renner

    Renner combustophile

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    +1

    it helps to wear latex gloves or similar for a slip-free grip between fingers while turning the needle through 90 degrees, at which point it can be drawn to the next pair of opposed notches, or out as the case may be.
    #3
  4. disston

    disston ShadeTreeExpert

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    You probably have to have Latex or some type of glove to get a grip on the smooth needle. I didn't have any nice clean new latex gloves the last time I did this and ended up with an old pair of gardening gloves in heavy rubber.

    Well it worked.

    Your leather motorcycle gloves probably won't work. The needle is slippery.
    #4
  5. Plaka

    Plaka Brevis illi vita est

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    record how much they stick out before you remove them. Just make a mark on a 3x5 card.
    #5
  6. boxerboy81

    boxerboy81 Stay Horizontal

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    http://youtu.be/vFnTVxm0FVw

    <iframe src="http://www.youtube.com/embed/vFnTVxm0FVw" allowfullscreen="" frameborder="0" height="315" width="420"></iframe>

    <embed
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    </embed

    <embed

    </embed
    #6
  7. CanadaBiker

    CanadaBiker Been here awhile

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    So i got the jet needles out, but damn, the new ones I ordered from Maxbmw are much longer. And the taper profile is much different. The part number seems correct, and it matches the fiche...

    Anyone have this problem?
    #7
  8. blaine.hale

    blaine.hale Long timer

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    What are the markings on them? There should be an X or some other markings to denote which needle is which.
    #8
  9. blaine.hale

    blaine.hale Long timer

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    Now that I think about it...I may have imagined doing that on my bings. I think I did that for my Amals haha.
    Sorry, way too many carbs in my life at the moment.
    #9
  10. daveoneshot

    daveoneshot Been here awhile

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    I've used lightweight Vice Grips, set real low on the squeeze scale, with rubber strips on the teeth. The job got done, but I almost had heart trouble while doing it. Latex gloves seems like a good idea.
    #10
  11. naginalf

    naginalf Handy Schtroumpf

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    I just ordered all new needles, jets, and whatnot from Max. Are you telling me they are the wrong part now? So what's the correct part number?
    #11
  12. CanadaBiker

    CanadaBiker Been here awhile

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    Not sure for your bike, but the 32mm Bings use nozzle needle (jet needle) 13111255840.

    However the fiche, at least for my bike, lists the part as 13 11 1 335 321, which is actually for the 40mm Bings. The confusion is that many of the R100s have the 40mm carbs, but the 'plain jane' R100/7 uses the 32mm carbs.

    Clear as mud? :)
    #12
  13. naginalf

    naginalf Handy Schtroumpf

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    I have 32s on my 91GSPD, and the fiche says PN 13 11 1 337 692 :huh I guess I'll see what happens when I get them apart.

    Oh, sorry, I'm probably just confusing things, didn't realize you guys are talking about 70's bikes which probably had different bings. Nevermind me.
    #13
  14. CanadaBiker

    CanadaBiker Been here awhile

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    I'll add some more mud. For 32mm Bings, the 13111255840 needles went to 1983. After that it was 13 11 1 337 692...

    However!! MotoBins shows the 1989 R100GSPD and onward using #13 11 1 338 522

    :)
    #14
  15. disston

    disston ShadeTreeExpert

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    I have checked realOEM dot com for your part numbers. The carbs on an R100/7 for 1977 are 64/32/19 & 20 The carbs on an R100RS for 1977 are 64/40/103 & 104

    Both the 32mm and the 40mm carbs list 13 11 1 335 321 as the jet needle.

    The #840 appears to be a much later GS or G/S needle, not sure.

    I seriously doubt that both Max BMW and Bob's BMW have made this mistake. If there was a mistake in the current fisch it wouldn't match the parts they have on the shelves and it would be rather impossible for this to be a long standing problem.

    I would use the new needles from Max. Those shorter needles that you are taking out are probably something an airplane mechanic or somebody used. (did you know many of these carbs are used on airplanes?)
    #15
  16. CanadaBiker

    CanadaBiker Been here awhile

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    Now you have me thoroughly uncertain.

    Rusty at MaxBMW seemed to confirm that I need the 13111255840 without me prompting him toward the 840s.

    Motobins shows different needles for the 32 vs 40.-- ...840 for 32 / ...321 for the 40s

    I wonder if people have just installed the 321's on a 32mm Bing bike and it ran ok.

    The 321's are longer than the 840's. And wouldn't a larger carb throat need a longer needle?

    Edit: I just got off the phone with Rusty at MaxBMW. (we had traded emails earlier) He confirmed that the fiche is wrong and that the 32 Bings take the shorter needles. I asked several times, and he was very certain. He said it's an error with the company or service? that manages the BMW Fiche and it gets carried over to the dealer level.
    #16
  17. disston

    disston ShadeTreeExpert

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    I had to edit my earlier post. I had listed the RS carb as a 32. I've changed it to 40.

    To begin with stop trying to figure our what all the possibilities are. Just get the needles you need. I think you already have them. The 321 needles.
    #17
  18. CanadaBiker

    CanadaBiker Been here awhile

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    Then why was Rusty so absolutely sure that 32 Bings use shorter needles than the 40 Bings?

    Plus:

    The needles that were in my carbs, possibly the original ones, are shorter than the 321 needles.

    Motobins lists different needles for the 32 vs 40 Bings (and matches Rusty's opinion on part #)

    I have 32mm Bings
    #18
  19. disston

    disston ShadeTreeExpert

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    So you say that Max and Bob's both said the 321 needle at first but now Rusty is saying that he agrees with Motobins and you want the 840 needle?

    I've heard good things about Rusty but that doesn't make him right.

    You could get both and see what works best? I don't think the needle has to be longer in a 40mm carb. I still think the 321 needle is right.

    But I could be wrong.

    From the picture you showed the longer needle looked like what I have in my carbs. (my R90/6 is the same vintage as your R100/7).
    #19
  20. supershaft

    supershaft because I can

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    Rusty and Motobins are right. I have run into this before. 40mm carbs do have longer needles. It makes sense to me.

    Why replace those needles to start with? They look fine in the photos. That type lasts WAY longer than the later type because of the different way they are mounted. The earlier mount setup doesn't let them vibrate and wear like the later setup does. If you can't feel a ridge with your finger nail on the straight part of the needle, they are fine.
    #20