Pilot Settings? 78 Carbs

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  • coltrain5000
    XSive
    • Mar 2010
    • 34
    • Ashburn VA

    #1

    Pilot Settings? 78 Carbs

    Hey Guys, was hoping to get a little input as to where everybody is at with turns on the pilot screws. I dont have a colortune.. yet. I'm not having very good luck going by ear and highest RPM method for each carb. I have searched and researched so I know stock settings are about 1.25 turns out and adjust from there. I'd like to know in general where I would be at considering my 78 carbs and drilled airbox..(more details in sig) I have mine out 2 full turns and it seems pretty good. Just a tad rich maybe? .. Plugs dont say, but the low end power is what I am judging. I went to 1.75 turns and power seemed to be down.

    Thanks!!
    1978 Macho Maroon XS1100 Mikesxs green coils, ZRX Carbs, spaghetti jardine 4 into 2
    1989 FXLR harley that is not stock
    1977 RD400 stage 2 ported with VM30 carbs
    1975 RD350 modified

    I can't leave anything alone
  • DGXSER
    Doctor of XSology(Deceased)
    • Nov 2008
    • 12001
    • Cincinnati, Ohio

    #2
    Every engine is different, the compression and the exhaust, the air inlets, condition of carbs, all play a part in that setting. So setting yours the same as someone elses will not do you any better than where you are at since it seems to be running decent or well where you are.

    Check plug color after a couple hundred miles and see where your at. if the lugs look nice and tan color, and your idle seems smooth and level. Thats the best indicator really.
    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

    • mro
      XS-XJ Super Guru
      • Oct 2005
      • 4276
      • Hayward, California

      #3
      The 1 1/4 out is a starting point for a stock XS.

      Tuning by ear is easiest if you can get it to idle around 850/900 rpm
      which makes it easier to detect any change.

      mro

      Comment

      • coltrain5000
        XSive
        • Mar 2010
        • 34
        • Ashburn VA

        #4
        Thanks for the input...

        Is each screw all over the place or are they generally about the same turns out? I suppose I will get on that color tune product and purchase.. Just hoping to get some general settings of other similar setups is all.

        Thanks for the advice.
        1978 Macho Maroon XS1100 Mikesxs green coils, ZRX Carbs, spaghetti jardine 4 into 2
        1989 FXLR harley that is not stock
        1977 RD400 stage 2 ported with VM30 carbs
        1975 RD350 modified

        I can't leave anything alone

        Comment

        • CatatonicBug
          Master of XSology
          • Oct 2008
          • 6117
          • Clinton, UT

          #5
          They are generally all similar on one bike, but 1/16th of a turn makes a difference, and as DG said, no 2 engines are the same, and no 2 carbs are the same. You may have one at 1.75, and another at 2.25.
          1980 XS850SG - Sold
          1981 XS1100LH Midnight Special (Sold) - purchased 9/29/08
          Fully Vetterized and Dynojet Kit added, Heated Grips, Truck-Lite LED headlight, Accel Coils, Irridium plugs, TKAT Fork Brace, XS850LH Final Drive & Black SS Brake lines from Chacal.
          Here's my web page devoted to my bike! XS/XJ User's Manuals there, and the XJ1100 Service Manual and both XS1100 Service manuals (free download!).

          Whether you think you can, or you think you cannot - You're right.
          -H. Ford

          Comment

          • DGXSER
            Doctor of XSology(Deceased)
            • Nov 2008
            • 12001
            • Cincinnati, Ohio

            #6
            Yes, IMO, if you have any one screw more than one turn different than another, something is not correct. Now, if compression is off in that cylinder that can also cause it.

            But it is not uncommon for noen of them to be exactly the same and off by a half to full turn I would not worry about.
            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

            • petejw
              XS-XJ Guru
              • May 2005
              • 2269
              • sydney australia

              #7
              the mixture screw settings
              should all be close to each other,
              if there not, then more than likely
              the float levels arent set exact to each other.
              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

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