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    Mechanical Carb Question

    Ok I have a 1978 GS1000. Pretty much stock, except it has a 4 into 1 pipe. I got it cheap (of course) rebuilt the carbs and the thing ran beautifully! With the exception that it was rich. So I take the carbs off and I lower the needles, This in theory will lean out the mixture. Well now it is almost impossible to start! I mean I have to crank for almost ever! It will idle at 1000RPM, but not as well as before. It is burning better and leaner now, but so hard to start!!!! Of course I also synched the carbs after doing all the work.

    So here is the question, I am thinking by lowering the needles the bike is not getting enough fuel when I am trying to start it. Does that make since, I am thinking maybe raise the needles back up and put in a size smaller jets (it currently has the stock jets). Anyone have a better idea??

    Thanks

    #2
    Krazy,
    The way the carb is designed the needles should not come into play on start up. With the throttles closed there is not enough airflow for this circuit to draw fuel.
    Remember, when starting the bike you should turn on the choke and leave the throttles closed. If you are using this procedure and the bike doesn't start, I would look at the idle and choke circuits. I know you changed the needles right before this problem flared it's ugly head but maybe someone else was trying to fix it and masked the problem by raising the needles.
    I have the factory manual and could try emailing some pages to you. I've had trouble trying to send these before so no promises. Mayby this time I could try 1 page at a time. I think there are 17 pages.

    Steve

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      #3
      On start up, the only circuits that are functional are the choke/enrichener and the fuel and air idle passages. If its hard to start, check that your idle fuel jets are clear and that the idle air passages are clear. For the mechanical VS series, 2 turns out on the fuel pilot and 1 1/2 turns out on the airscrew should give you a pretty rich startup mixture. Be sure and do not touch the throttle on startup. Regulate rpm with the choke knob until its warmed up a bit.

      Earl.
      Komorebi-The light filtering through the trees.

      I would rather sit on a pumpkin and have it all to myself than be crowded on a velvet cushion. H.D.T.

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        #4
        If you did'nt know,there are spacers available at some shops or Dynojet.
        They measure .023'' thick and are equal to moving the needle clip a 1/2 a notch position. The spacer goes on TOP the clip. So for example if you started with the clip in #3 notch(too-rich),then tried #2 notch(too-lean),you might try putting the clip back in #3 notch with the spacer on top of clip. This puts the needle right between. And like the others say,I would make sure the starter and idle circuits were clean and check o-rings. KK.
        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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