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78 gs1000c jetting

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    78 gs1000c jetting

    I’m sure this has been discussed plenty of times before but can someone give me a baseline stating point for main jets, pilot jets, and needle clip position? Bike is running pods with stock exhaust in which previous owner gutted the baffles out. Thanks

    #2
    Are you keeping the bike the way it is currently set up?

    Stock jetting specs.
    2@ \'78 GS1000

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      #3
      Yea, probably easier for me to get a few jets and move the needle height than it would be to find an airbox and a stock baffled exhaust. I did this on a gs750 a few years back and it ran very well. I believe I went up 5 sizes on main, 1 size on pilot, and raised the needle 2 slots. I’m sure someone has rejected one before on here so thought I’d ask her first.

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        #4
        Some good info in this thread.
        2@ \'78 GS1000

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          #5
          I never have figured out why everyone wants to add one (or more) size to the pilot jet.

          The only reason you need to increase the fuel jets is because of added air. The added air is because you have removed the restriction of the airbox. That restriction really only affects airflow at the upper RPMs and near-wide-open throttle settings. The pilot jets are at the OTHER end of the RPM range, and at throttle settings where the throttles are the limiters, not the airbox.

          .
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            #6
            You shouldn't need to up the pilot jets are Steve has already said. Just adjust them top & bottom...
            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.....

            www.parasiticsanalytics.com

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

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              #7
              Got it running pretty great today. Here’s what I ended up with...

              drilled out some old 107.5 mains with a #54 drill (.055”)
              raised the needle by 1 slot. (4th slot from top of needle)
              1 turn out on mixture screw on bottom of carb
              2 turn outs on mixture screw on side of carb
              17.5 pilots. Little rich at idle so will probably go back to 15’s

              Synched the carbs with carbtune.
              Still need to check with a colortune. Will get to that in the next couple of days

              Bike doesn’t miss a lick and pulls strong at all rpms up to redline and idles well.

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