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  • Easy carb question

    Before I remount my carbs, yet again - by the way, I went from fully assembled bike to carbs on the workbench within the first three commercial breaks of CSI: Miami without missing any of the show - I have a very basic question on float height.

    On most of my other bikes, to set correct float height you have to set the carbs at about a 40 degree angle from horizontal and you set the float at the point where the tang just makes contact with the pin without compressing it. The directions for my XS, however, seem to indicate that you set float height with the carbs turned all the way over and sitting upside down with the float resting on the pin. Am I reading this correctly?

    Thanks,

    Patrick
    The glorious rays of the rising sun exist only to create shadows in which doom may hide.

    XS11F (Incubus, daily rider)
    1969 Yamaha DT1B
    Five other bikes whose names do not begin with "Y"

  • #2
    Succubus:

    Yes; the height is measured from the base of the carb without the gasket in place to the top of the float. This up side down will change the level of the fuel in relation to the height. the higher the float, the less fuel in the bowl, and conversely, the lower the height the more fuel in the bowl. For example the 79 float height is set to 25 mm+or - .5 mm, whereas the 80 float is set to 23mm +or-.5mm. That puts more fuel in the 80 bowl as the pilot towers are plugged and the pilot jet receives it's fuel through the main jet via a drilled hole about 1/2 up in between the main tower and the pilot tower. Of course care must be taken as the bowl will over flow at aboutt 21mm which is not a lot of leeway. A member of the site has devised a method of measuring the fuel height while on the bench. Do a search on float height.

    Comment


    • #3
      See... learn something every day!!

      I have always, and always heard that you set them while upside down resting on the float valves. I thought this would simulate the pressure of the bouyant float pressing against the valve? I guess I need to read my book a little closer! lol.

      BUT.. looking at the postings of people on carbs in the past, they have all seemed to do it with the carbs completely inverted that I have seen.

      Tod
      Try your hardest to be the kind of person your dog thinks you are.

      You can live to be 100, as long as you give up everything that would make you want to live to be 100!

      Current bikes:
      '06 Suzuki DR650
      *'82 XJ1100 with the 1179 kit. "Mad Maxim"
      '82 XJ1100 Completely stock fixer-upper
      '82 XJ1100 Bagger fixer-upper
      '82 XJ1100 Motor/frame and lots of boxes of parts
      '82 XJ1100 Parts bike
      '81 XS1100 Special
      '81 YZ250
      '80 XS850 Special
      '80 XR100
      *Crashed/Totalled, still own

      Comment


      • #4
        by the way, I went from fully assembled bike to carbs on the workbench within the first three commercial breaks of CSI: Miami without missing any of the show
        I assume you have a TV in your garage and not a workbench in your livingroom. If not see this thread posted by planedick http://www.xs11.com/forum/showthread...threadid=17685

        Float height tips at http://www.xs11.com/forum/showthread.php?s=&threadid=76


        trbig,

        I'm not sure if I'm reading you right but are saying you adjusted your floats with the carbs in the upright position? That would be trickier than balancing on ones head.
        Ernie
        79XS1100SF (no longer naked, now a bagger)
        (Improving with age, the bike that is)

        Comment


        • #5
          Nope, no TV in the garage and no workbench in the living room. Process: watch show, commercial comes on, go out in garage, work three minutes, go back to TV. Repeat at next commercial break.

          I have set the floats with the carbs inverted, with the gaskets off. Just for grins, however, last night I set them the way I set my other carbs. There is a significant difference in where the float height ends up with the two different methods, since the 40 degree method has no weight in the needles and the inverted method leaves the weight of the floats on the needles. The height difference seems to be at least a mm or two, although I did not precisely measure it.

          I just want to make sure I'm doing it the prescribed way, since it's different with these carbs, apparently.

          Patrick
          The glorious rays of the rising sun exist only to create shadows in which doom may hide.

          XS11F (Incubus, daily rider)
          1969 Yamaha DT1B
          Five other bikes whose names do not begin with "Y"

          Comment


          • #6
            ????


            Carbs upside down. Not at the 40 degree angle.
            Try your hardest to be the kind of person your dog thinks you are.

            You can live to be 100, as long as you give up everything that would make you want to live to be 100!

            Current bikes:
            '06 Suzuki DR650
            *'82 XJ1100 with the 1179 kit. "Mad Maxim"
            '82 XJ1100 Completely stock fixer-upper
            '82 XJ1100 Bagger fixer-upper
            '82 XJ1100 Motor/frame and lots of boxes of parts
            '82 XJ1100 Parts bike
            '81 XS1100 Special
            '81 YZ250
            '80 XS850 Special
            '80 XR100
            *Crashed/Totalled, still own

            Comment


            • #7
              I have a very basic question on float height

              within the first three commercial breaks of CSI: Miami
              I have a very basic question about your taste in what passes for televised entertainment.... but I shall save that for later.
              Yes, it's true, it's true...
              Different float techniques for different bikes.
              Some old Kawa's, fr'instance, say to have the carbs at an angle.
              Ours are to be flat on their backs.
              Can't say that it matters much. The weight of the float doesn't push that spring-loaded stud on the float needle down anyway.
              "Damn it Jim, I'm a doctor, not a mechanic!' ('Bones' McCoy)

              Comment


              • #8
                "I have a very basic question about your taste in what passes for televised entertainment"

                You are assuming, Pro, that this was my choice. My choice was working on my carbs. I, however, have been married since the Earth cooled and there are certain things I am expected to share. Which is why I couldn't just take nine straight minutes to pull my carbs.

                We all have our burdens....

                Patrick
                The glorious rays of the rising sun exist only to create shadows in which doom may hide.

                XS11F (Incubus, daily rider)
                1969 Yamaha DT1B
                Five other bikes whose names do not begin with "Y"

                Comment


                • #9
                  have been married since the Earth cooled
                  AHHAhahahahhaaaa...!
                  "Damn it Jim, I'm a doctor, not a mechanic!' ('Bones' McCoy)

                  Comment

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