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    Another carb question?? 81 GS550T

    Hey guy's. My 81 GS550T stumbles off of idle and has a slight hesitation when taking off. After a while (about 10-15 mins.) it clears up which makes me believe it's a lean lean condition. If I ride around with the choke slightly pulled it runs fine. Not that it runs bad with the choke pushed in and like I said, it runs fine after a while but it seems to take a while for it to get there. Do these bikes tend to be cold natured? Carbs are clean, idles nice (even when cold), and starts easy. I haven't had the carbs synched. Are the needles adjustable on these and should I raise them a notch? The plugs have been drilled out and mixture screws are @ 3 turns out. What is the correct setting for the screws? The bike has stock pipes and air filter. Any help would be greatly appreciated!! Thanks!

    #2
    Originally posted by mafd2 View Post
    Hey guy's. My 81 GS550T stumbles off of idle and has a slight hesitation when taking off. After a while (about 10-15 mins.) it clears up which makes me believe it's a lean lean condition. If I ride around with the choke slightly pulled it runs fine. Not that it runs bad with the choke pushed in and like I said, it runs fine after a while but it seems to take a while for it to get there. Do these bikes tend to be cold natured? Carbs are clean, idles nice (even when cold), and starts easy. I haven't had the carbs synched. Are the needles adjustable on these and should I raise them a notch? The plugs have been drilled out and mixture screws are @ 3 turns out. What is the correct setting for the screws? The bike has stock pipes and air filter. Any help would be greatly appreciated!! Thanks!

    Just about all these old GS bikes run lean from stock - Suzuki was famous for this back then. These are air cooled motors, and the motor has a LOT of metal in it, so it takes a while for everything to come up to operating temperature. As long as your bike cleans up when warm you shouldn't have to do anything. You could try raising the needle (with a washer?) but I wouldn't do too much or you are just wasting gas.
    Ed

    To measure is to know.

    Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

    Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

    Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

    KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

    Comment


      #3
      Thanks for the reply. I may try raising the needle a bit. I was gonna get a Dynajet kit but not available for the 550's. Is there an alternate needle I can use? One that is richer than stock? I've looked at Sudco but they list tons of them and I wouldn't know where to start. Also, what is a good setting for the idle mixture screws? Isn't clockwise richer? I've heard some say use maximum rpm method. Any guidence on that? I'm use to my old RM single carbs and just getting my feet wet with these CV 4 carbs. Thanks for the help guys!

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        #4
        I have no idea about different needles. I have an '81 550T myself, with the carbs on the workbench, so I'm going to check into maybe placing a small washer under the needle to shim them 1mm or so. Not sure if it will do anything but it's worth a try.

        Regarding the mixture screws, you want to screw it in all the way and then count the turns when you back them out. I usually turn them out 2.5 turns or so from closed. And yes, listen to idle speed increases and set them for the fastest idle in and around 2-3.5 turns out.

        Good luck.
        Ed

        To measure is to know.

        Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

        Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

        Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

        KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

        Comment


          #5
          Check radio shack for the washers. Two Washers = one notch on an adjustable needle.
          1983 GS 1100E w/ 1230 kit, .340 lift Web Cams, Ape heavy duty valve springs, 83 1100 head with 1.5mm oversized SS intake valves, 1150 crank, Vance and Hines 1150 SuperHub, Star Racing high volume oil pump gears, 36mm carebs Dynojet stage 3 jet kit, Posplayr's SSPB, Progressive rear shocks and fork springs, Dyna 2000, Dynatek green coils and Vance & Hines 4-1 exhaust.
          1985 GS1150ES stock with 85 Red E bodywork.

          Comment


            #6
            Sometime back, I needed some needle washers and I contacted Dynojet and they sent me a pack of about 50 at no charge. the thing is if these are big enough to fit around the stock needle. Seems the Dynojet needles are smaller in diameter. Are you having lean condition problems with your 550T also? If these washers don't work I guess I will try Radio Shack. Thanks again Guys!

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              #7
              Not to change the subject here...but I tore into my carbs today. The bike is low mileage but has sat a LONG time - check my thread http://www.thegsresources.com/_forum...ad.php?t=99040
              The float bowls, and some of the jets, look GREEN on the inside. I've always just cleaned out the jets when they are gunked up but I'm not sure about these things. Going to try dipping some of the parts to see if it helps. If so, I'll break down the carbs competely which I hate to do as a rule.

              At any rate, good luck with yours.
              Ed

              To measure is to know.

              Mikuni O-ring Kits For Sale...https://www.thegsresources.com/_foru...ts#post1703182

              Top Newbie Mistakes thread...http://www.thegsresources.com/_forum...d.php?t=171846

              Carb rebuild tutorial...https://gsarchive.bwringer.com/mtsac...d_Tutorial.pdf

              KZ750E Rebuild Thread...http://www.thegsresources.com/_forum...0-Resurrection

              Comment


                #8
                BERRYMANS carb cleaner is the best... I have used it on aircooled VW cases and heads since the EPA zapped the chem co's. Do not put painted parts in it because it will REMOVE the paint. Do not put any RUBBER in it as it will ruin it. Do not get on your skin as it will BURN (removes ALL oils from your skin).

                Comment


                  #9
                  IF you have the CV carbs the best thing you can do is complete dissambly & replace EVERY O RING

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