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  • Older style carbs

    Working on my first set of the 78-79 version of the carbs. How can I tell if it is a 78 or 79 setup? Did they use different needle jets or emulsion tubes from 78 to 79?

    The air, pilot, and mains are not right at all. look to eb aftermarket and 40 pilots with 130 mains, and 180 pilot air jets. So I am trying to figure if I should jet with 42.5 or 45 pilot jets. Plan is to clean them up and get them setup and ready to run, then send to a new owner yet to be named or determined. They have the plastic floats, so going with the XV920 float valves. So I could go either way, but if the needle and emulsion tubes determine a setup, that is the way I want to go with it.
    Life is what happens while your planning everything else!

    When your work speaks for itself, don't interrupt.

    81 XS1100 Special - Humpty Dumpty
    80 XS1100 Special - Project Resurrection


    Previously owned
    93 GSX600F
    80 XS1100 Special - Ruby
    81 XS1100 Special
    81 CB750 C
    80 CB750 C
    78 XS750

  • #2
    hey dgxser,

    heres a good link from the uk site with carb specs
    for all the models.

    http://www.benefiscal.co.uk/forum/in...p?topic=3775.0
    pete


    new owner of
    08 gen2 hayabusa


    former owner
    1981 xs1100 RH (aus) (5N5)
    zrx carbs
    18mm float height
    145 main jets
    38 pilots
    slide needle shimmed .5mm washer
    fitted with v/stax and uni pod filters

    [url]http://www.youtube.com/watch?v=3pA8dwxmAVA&feature=mfu_in_order&list=UL[/url]

    Comment


    • #3
      Didn't the 79 have 180 air jets? 78 had 210.
      Nathan
      KD9ARL

      μολὼν λαβέ

      1978 XS1100E
      K&N Filter
      #45 pilot Jet, #137.5 Main Jet
      OEM Exhaust
      ATK Fork Brace
      LED Dash lights
      Ammeter, Oil Pressure, Oil Temp, and Volt Meters

      Green Monster Coils
      SS Brake Lines
      Vision 550 Auto Tensioner

      In any moment of decision the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing.

      Theodore Roosevelt

      Comment


      • #4
        Carbs

        DGXSER:

        According to my Clymer Manual, the 78E and 78F had the same main jet (137.5), the same needle jet or emulsion tube (X-2), same pilot jet (42.5) and same air pilot jet (180). The jet needle is a 5GZ6.

        Don't know if this helps.

        Geobiker
        1979 F
        Mac 4-2 Exhaust
        T-Kat Fork Brace
        Spade Fuse Box Mod
        Stainless Steel Braided Brake Lines
        140.0 Main Jets
        45.0 Pilot Jets
        266 X-2 Needle Jets

        Comment


        • #5
          Originally posted by DGXSER View Post
          The air, pilot, and mains are not right at all. look to eb aftermarket and 40 pilots with 130 mains, and 180 pilot air jets. So I am trying to figure if I should jet with 42.5 or 45 pilot jets. .
          Maybe the pilots were downsized to compensate for being the wrong type and resulting previous probs with being too rich? The right type has a small oriface at the upper end (as installed). I never owned a 79, but the 78 does have 210 air's.
          Skids (Sid Hansen)

          Down to one 1978 E. Stock air box with K&N filter, 81H pipes and carbs, 8500 feet elevation.

          Comment


          • #6
            Originally posted by geobiker View Post
            DGXSER:

            According to my Clymer Manual, the 78E and 78F had the same main jet (137.5), the same needle jet or emulsion tube (X-2), same pilot jet (42.5) and same air pilot jet (180). The jet needle is a 5GZ6.

            Don't know if this helps.

            Geobiker
            this is one of those situations where the clymer manual is wrong.
            Nathan
            KD9ARL

            μολὼν λαβέ

            1978 XS1100E
            K&N Filter
            #45 pilot Jet, #137.5 Main Jet
            OEM Exhaust
            ATK Fork Brace
            LED Dash lights
            Ammeter, Oil Pressure, Oil Temp, and Volt Meters

            Green Monster Coils
            SS Brake Lines
            Vision 550 Auto Tensioner

            In any moment of decision the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing.

            Theodore Roosevelt

            Comment


            • #7
              If you follow the Clymers recommendation for the 79, you should be good. This would be for a stock setup, of course.

              pilot jets 42.5/180
              main: 137.5
              float level 25.7mm

              The 210 air jet setup is for the 78 and very early 79 models with the hot cams. IIRC, they also used a 45 pilot.
              2H7 (79) owned since '89
              3H3 owned since '06

              "If it ain't broke, modify it"

              Comment


              • #8
                Originally posted by natemoen View Post
                this is one of those situations where the clymer manual is wrong.
                Even the factory manual is wrong; my '78 FSM calls out a 180 pilot, but my unmolested-since-new carbs had 210s in 'em...
                Fast, Cheap, Reliable... Pick any two

                '78E original owner - resto project
                '78E ???? owner - Modder project FJ forks, 4-piston calipers F/R, 160/80-16 rear tire
                '82 XJ rebuild project
                '80SG restified, red SOLD
                '79F parts...
                '81H more parts...

                Other current bikes:
                '93 XL1200 Anniversary Sportster 85RWHP
                '86 XL883/1200 Chopper
                '82 XL1000 w/1450cc Buell, Baker 6-speed, in-progress project
                Cage: '13 Mustang GT/CS with a few 'custom' touches
                Yep, can't leave nuthin' alone...

                Comment


                • #9
                  The only difference I know of is that the 78 has a larger Starter Jet size in the bowl. But, this won't help identify one from the other. On a more positive note, it doesn't matter which is which because everything else is the same.
                  '81 XS1100 SH

                  Melted to the ground during The Valley Fire

                  Sep. 12th 2015

                  RIP

                  Comment


                  • #10
                    My 79 made in april 78 came with 140 mains 45 pilots and 210 airjets. There are a few older posts about this. I don't think the 78's were 210 air though. If you look at some of the parts fische you will see two different jettings for 79 search for one of my previous threads
                    " She'll make point five past lightspeed. She may not look like much, but she's got it where it counts, kid. I've made a lot of special modifications myself. "

                    79 xs11 standard
                    xs pods, Kerker 4-1, zrx1200r carbs mikesxs coils 35k voltz of power!!!
                    8mm msd wires
                    tkat fork brace...
                    Fox shocks...
                    mikes650 front fender
                    led's gallore...
                    renthal bars
                    gold valve emulators
                    vmax tensioner
                    Rifle fairing

                    Comment


                    • #11
                      Looking over all the great input, gives me plenty to think on. Most likely go with the 42.5 pilots, looks like they have the correct pilot air jets for that and get new mains the right size. Especially since my test bike is the 81 model, (have to test them before I'd send them to a new home) it might run like crap on those large pilots and air jets with the milder set up.

                      Thanks for all the great input!
                      Life is what happens while your planning everything else!

                      When your work speaks for itself, don't interrupt.

                      81 XS1100 Special - Humpty Dumpty
                      80 XS1100 Special - Project Resurrection


                      Previously owned
                      93 GSX600F
                      80 XS1100 Special - Ruby
                      81 XS1100 Special
                      81 CB750 C
                      80 CB750 C
                      78 XS750

                      Comment


                      • #12
                        Also, needle clips should be in the 3rd (center) position.
                        2H7 (79) owned since '89
                        3H3 owned since '06

                        "If it ain't broke, modify it"

                        Comment

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