carb guru question

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  • dtkid

    #1

    carb guru question

    Hey Folks:

    I am presently running my 81' GS1100E with a set of carbs from an 80' GS750. The carbs have been stage 3 jetted.

    This set-up works excellently and is never, ever cold natured (I ride everyday that the roads aren't iced over; no matter the temp) and always fires with first or second turn of the crank.

    However, I need those carbs for another GS750. I have a set of GS1100 carbs but the bike don't want to start with this rack. My question is this:

    Should I be able to replace the GS1100 carb pilot jets and pilot air jets to match those in the GS750 carbs (which the 1100 loves?)

    Said another way: I want to match the pilot jets and pilot air jets on the GS750 carbs (that the machine loves) with those in the GS1100 carbs that I now possess.

    Should making sure that the pilot jets and pilot air jets are consistent between the two carb sets provide the same starting mixture for the two sets of carbs?

    (Gee I hope that question makes sense. I had some trouble expressing my dilemma.)
  • salty_monk
    Forum LongTimer
    GSResource Superstar
    Past Site Supporter
    Super Site Supporter
    • Oct 2006
    • 14001
    • London, UK to Redondo Beach, California

    #2
    Hmm that's an interesting one... I guess if the airflow is the same with both racks, in theory yes it sounds good but I'm not sure. It wouldn't take much to try it though!

    Dan
    1980 GS1000G - Sold
    1978 GS1000E - Finished!
    1980 GS550E - Fixed & given to a friend
    1983 GS750ES Special - Sold
    2009 KLR 650 - Sold - gone to TX!
    1982 GS1100G - Rebuilt and finished. - Sold
    2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

    www.parasiticsanalytics.com

    TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

    Comment

    • rapidray
      Forum Guru
      GSResource Superstar
      • Oct 2006
      • 8195
      • So Cal

      #3
      The 750 carbs are smaller diameter so LESS air flow. To jet the 1100 carbs the same would make them LEAN. Ray.

      Comment

      • Guest

        #4
        Clean out those 1100 carbs and wake up the beast. You are not running it to potential.
        What mods (if any) are on the 1100 and I can help you jet it but they have to be clean with new o-rings installed.

        Comment

        • dtkid

          #5
          I "stage 3 jetted" the 1100 carbs (Dynajet Kit) a couple of years ago. However, while I was working on the 1100 carbs I decided to put the extra set of stage-3-jetted 750 carbs on the bike. Low and behold it ran superbly. Inasmuch as it was winter (last winter) and inasmuch as the bike never, ever seemed 'cold-natured', I just left the carbs on (because I ride everyday the roads aren't icy.)

          As I stated though, I now want to put the 1100 carbs on the GS1100. I DID a couple of weeks ago but the bike did not want to start..........then I remembered that I had screwed around and changed the pilot jet and pilot air jet.

          Chief: can you tell me the stock pilot jet and pilot air jet for the 1100 carbs? I checked a couple of threads but can never seem to find the correct pilot-air-jet size.

          Also, I am fairly sure that the pilot-"stuff" is involved in starting the machine. Am I correct in that assumption; or is their a completely seperate "starter-jet" circuit?

          Comment

          • salty_monk
            Forum LongTimer
            GSResource Superstar
            Past Site Supporter
            Super Site Supporter
            • Oct 2006
            • 14001
            • London, UK to Redondo Beach, California

            #6
            No, you're right. Pilot circuit is for idle & starting plus "topped up" by the chokes.

            There is a sticky thread with all the stock sizes in it in one of the forums... take a look at it.

            Dan
            1980 GS1000G - Sold
            1978 GS1000E - Finished!
            1980 GS550E - Fixed & given to a friend
            1983 GS750ES Special - Sold
            2009 KLR 650 - Sold - gone to TX!
            1982 GS1100G - Rebuilt and finished. - Sold
            2009 TE610 - Dual Sporting around dreaming of Dakar..... - FOR SALE!

            www.parasiticsanalytics.com

            TWINPOT BRAKE UPGRADE LINKY: http://www.thegsresources.com/_forum...e-on-78-Skunk/

            Comment

            • Guest

              #7
              Pilot jet 45
              Pilot air jet 160
              Main jet 107.5

              Comment

              • dtkid

                #8
                Thanks fellas. I'll be settin' up the carbs and puttin' them on this weekend. I'll let you know how she motors.

                Comment

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