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    carb problem ?

    just replaced all inlet rubbers between head and carbs also added seperate kn filters after giving the carbs a rebuild also 4 into 4 stock harley exhausts,the problem is engine will start and idle fine,but struggles to pick up speed and can't get over 40mph,bike is running on all 4 cylinders
    going to balance the carbs,is there any thing else that may need doing or to look out for?
    running a gs850 trike with 32 vc mikuni carbs
    thanks

    #2
    You need to rejet the carbs to balance the increased airflow from the seperate air filters and free flowing exhaust. Dynojet stage 3 kit will fix you up.
    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

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      #3
      Yeah, you're gonna need to rejet. The bike's getting "too much" air in comparision to how much fuel is flowing through the carbs...
      1980 Gs550e....Not stock... :)

      Comment


        #4
        Originally posted by Nessism View Post
        You need to rejet the carbs to balance the increased airflow from the seperate air filters and free flowing exhaust. Dynojet stage 3 kit will fix you up.
        The old "air fuel ratio"... ditto!!!!

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          #5
          If it can't get over 40 mph, it isn't a lean mixture. More likely, not enough air.
          Did you over-oil those K&N's or use a non-recommended oil? Very easy to oil them too much.
          Clean them with K&N cleaner or a solution of dish soap and water. Allow to stand about 20 minutes. Then rinse with low pressure water from THE INSIDE OUT ONLY to avoid compromising flow and cleaning ability. Air dry only. Then re-oil correctly. Following K&N's own advice to "hold can 3 inches away and spray each pleat" can lead to over-oiling. I hold the can about 4 inches away but hit 2 to 3 pleats at a time with one pass. The filter should be a light red after oiling and waiting 10 minutes. If dark red, too much oil. With too much oil, start up and idle will be fine. Cruise up the street with just a little throttle and it's fine. But try to open it up at all, you should get bucking acceleration. Try to open it up fully, dead bog.
          After that's fixed, don't forget to check jetting.
          And on the seventh day,after resting from all that he had done,God went for a ride on his GS!
          Upon seeing that it was good, he went out again on his ZX14! But just a little bit faster!

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            #6
            have rejeted carbs with 130 as that is all i have at moment
            but think are to big got more speed 60 mph bit slugish on pick up and plenty of back fireing will try smaller jets 120-124 and i'll let you now if this is ok

            Comment


              #7
              I assume your acceleration problem begins at a much smaller throttle opening. How exactly are you opening the throttle to have the problem?
              The main jet change will only effect 3/4 to full throttle openings.
              So there's no way the filters are over-oiled or oiled with incorrect oil?
              And on the seventh day,after resting from all that he had done,God went for a ride on his GS!
              Upon seeing that it was good, he went out again on his ZX14! But just a little bit faster!

              Comment


                #8
                yes pick up problem starts from the off,opening the throttle steady,never crank it right back,think the problem is still the main jet got some 122.5 coming still got to balance the carbs thoe

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                  #9
                  had alook at the carbs,one of the throttle valves was sticking sorted that,also removed the bungs above the pilot jets ,ran it again with 130 jets,good pick up,but at the point of engine needing to change gear,engine starts to splutter through all the gears but did get 70mph out of her,still think the jets are to big will try smaller ones 122 as soon as i get them,still got to balance carbs thoe

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                    #10
                    got the 122 jets fitted them,took it for a run
                    pick up very good up to 60mph then dies off a bit can now get 80mph maybe more
                    think the top end will be restricted due to the diff in the reliant axle,but never mind i'm happy with that
                    thanks for your help every one

                    Comment


                      #11
                      Don't remove the bungs above the pilot jets.

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                        #12
                        what dothe bungs actually do?

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                          #13
                          Not sure what they're for... but there are a number of posts I've seen here on the GSR in the past, of folks suddenly curing all their fuel problems when they realised the bungs were missing, and they slotted a set back in.

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