950 carb refurbishing - pitfalls and experiences, please?

Discussion in 'Dakar champion (950/990)' started by Orange Toaster, Feb 28, 2013.

  1. motolab

    motolab Long timer

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    #61
  2. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    You are the first person to say that. Myself and many others on here have used those with no issues as a matter of fact I installed them yesterday on my Adventure. Having matched up the OEM with the ones I posted there is no difference and the size is correct.

    http://advrider.com/index.php?threads/o-ring-hail-mary-950-carbs.959522/#post-23622754
    #62
  3. BHDuryee

    BHDuryee Adventurer

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    Does anyone know where to get the fuel screw orings other than in the carb rebuild kit?
    #63
  4. motolab

    motolab Long timer

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    Sounds like argumentum ad populum.
    Well, lets have a closer look.

    The groove OD is 7.31 mm, and the stretch specification provided by various o-ring manufacturers for a piston type application is 0-5%, which works out to an o-ring ID of 6.96-7.35 mm.

    The bore ID is 9.21 mm, and the compression target specification provided by various o-ring manufacturers for a piston type application is 20%, which works out to an o-ring CS of 1.14 mm. The absolute maximum allowable is 30%, which still works out to only 1.24 mm.

    The reason the 6.1 X 1.3 mm o-ring goes together OK is because the the CS is reduced from stretching (in this case overstretching) - not an ideal situation.

    Regards,

    Derek
    #64
  5. motolab

    motolab Long timer

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    I carry them in stock in an FKM material.

    Regards,

    Derek
    #65
  6. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    Have you ever had any new OEM orings to measure? That is exactly the size of the OEM orings. I guess when Keihin speced the orings they fucked up.

    And I'm not the only person to measure them at that size.
    #66
  7. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    #67
  8. motolab

    motolab Long timer

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    Not of this particular item. I measure OEM when when it's important. If it's not, I do it if the opportunity presents itself. In this case, while interesting, it's not overly important. Measuring the components is much more accurate and reliable, and if I'm selling the product, the buck has to stop with me, i.e. I'm responsible for whether the product works properly or not.

    Consider that measuring o-rings accurately is not as straight forward as measuring parts, i.e. it can be difficult to do accurately and repeatedly, that o-rings have tolerances, and that there is no way to know which end of the tolerance the particular dimension of the o-ring one is attempting to measure is on.
    OK.
    It sounds possible.
    OK. But I'm not sure I understand what I'm supposed to take away from this.

    Regards,

    Derek
    #68
  9. DELTATANGO

    DELTATANGO Motorcyclist and Dog Walk

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    I just finished starting mine up after the winter. It was rough and popping. I think a float was stuck. A thought occurred to me. My wife bought a nice ultrasonic toothbrush. I got it and held it on the float bowls about a minute each. Unthinkly I did also tap on them with a screwdriver. But I think it was her toothbrush. I already cleaned her toothbrush. Don’t start.
    #69
  10. BHDuryee

    BHDuryee Adventurer

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    Thanks fellas!
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  11. vanlierde

    vanlierde Adventurer

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    Hi guys, I keep having problems with my 950, pulls strong till 5500rpm, then hesitates a lot until 7000rpm and then pulls back strong again. I keep finding very fine gray sand in the carb bowls and it clogs up the main jet. already cleaned out the tanks, installed new fuel lines and ultrasound cleaned the carbs. switched to different gasstations. yesterday I opened the carbs again, and saw something I never thaugt about checking, the vacuum piston, is it normal that they are slightly covered in e thin layer of grayish grease? If not, maybe they "melted" in the ultrasound bath and are disintegrating?

    thx in advance, and sorry if I make spell errors, english is not my native language.
    #71
  12. Zuber

    Zuber Zoob Supporter

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    That's a classic problem (hesitation at 5-7k) of not having the carb float bowls vented outside of the airbox. 11" hose on the front, 10" on the rear, stuffed down into the Vee of the motor, out of the breeze.

    Of course if you don't have the airbox, then you have a lot of other jetting problems.
    #72
  13. Hydra5

    Hydra5 Adventurer

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    Hey there fellas, anyone have advice on changing out the slide diaphragms?
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  14. gearheadE30

    gearheadE30 @LC8Adventures Supporter

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    Don't lose the little brass air jet in the sealing bead of the diaphragm, and the usual make sure everything is clean before you start taking it apart and dropping dirt where dirt shouldnt' be. Otherwise, it's about as straightforward a change as it gets. Pull the diaphragm covers, pull out the old ones, swap the needles over to the new ones, and reinstall.
    #74
  15. Hydra5

    Hydra5 Adventurer

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    If you're talking about swaping out the entire slide and diaphragm, that's for sure easy. I want to remove the diaphragm from the slide and replace just the diaphragm. It looks like it's possible to stretch the new one over the top of the slide and get it to slip into the groove with a little soapy water. I've seen it done on a different type of slide and I'm wondering if the same technique would apply here. Thanks
    #75
  16. geometrician

    geometrician let's keep going...

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    They are pretty easy- the most I'd use is some Windex for lubrication- you'll get a feel of what it takes when you remove the old diaphragms, the new ones snug right in place
    #76
  17. Boatman

    Boatman Membership has it's privileges ;-) Supporter

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    So did you actually get just the diaphragms?
    #77
    Stephen and SpeedyR like this.
  18. Hydra5

    Hydra5 Adventurer

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    So long story short, after talking to the guy at Parts Fiche, it looks like they don't sell just the diaphragm alone and the part number that I thought might be the diaphragm is actually the cover for the US bikes. 2005's have 2 numbers for the cover and 2006's have just one, but the 05 numbers have a different name/discription in the listing. Motosport has the same listing and OEM numbers for both years as well, admittedly confusing by the guy at Parts Fiche. I ended up ordering the whole slide cuz mine are cracked and one has a pin hole in it, any extra research on this just seemed like a waste of time. Sorry guys
    #78