KZ Carb Setup

Home › Forums › Shifter Karts › KZ Carb Setup

Viewing 7 reply threads
  • Author
    Posts
    • August 3, 2013 at 2:35 am #5897
      Martin
      Participant

      Hi Guys, I have a few q’s on carb setup Alot of people here in australia run lean needles and rich mains. (ie k22 266 and 168) but the tendency in europe is to run rich needles and leaner mains. ie k8 needles, 140-150 mains, etc Why is that so? Is it simply better that way, or is it a characteristic of circuits.

      Also, if the circuit has long straights as opposed to one with twisty corners, do you go jet richer bottom or tops? Do revs make a difference?

    • August 3, 2013 at 4:57 pm #5958
      Thomas Barth
      Participant

       

      Martin,

      A K22 needle has a 1.80mm diameter tip. A K8 needle has a 1.50mm tip, .30mm difference.

      I.E there is minimal difference in the annulus created by the needle tip/main jet between K22/168 and K8/140.

      168/K22 = 138/K8. Both needles have the straight section diameter of 2.50mm

       

      Different needles can have different tip diameters. The needle tip size is part of the equation when calculating annulus created by needle tip and main jet.

      Probably better to jet a little rich if track has long straight(s).

       

    • August 4, 2013 at 3:11 pm #6008
      Martin
      Participant

      Tom,

      This is true, but a k22 and162 vs k8 and 132 are only ‘equal’ (ignoring taper) during the bottom end phase.

      Once its full throttle, dont you see the huge difference between 132 and 162

    • August 5, 2013 at 4:38 pm #6104
      Thomas Barth
      Participant

      Hi Martin,

      The tip of the needle is included in the math when calculating the annulus of the tip/main jet area. This area (annulus) meters fuel at wide open throttle. At any position other than WOT, the taper/main jet/atomizer meters the fuel.

      once it’s full throttle, don’t you see the huge difference between 132 and 162.

      Yes.

    • August 6, 2013 at 12:36 am #6127
      Martin
      Participant

      So if a k8 /132/266 is exactly equal to a k22/162/266 (at WOT), why would you run one and not the other?

    • August 6, 2013 at 4:24 pm #6250
      Thomas Barth
      Participant

      You could run either set up and probably not see any difference in performance.

    • August 7, 2013 at 3:57 am #6295
      Martin
      Participant

      Thats amazing! haha

    • August 8, 2013 at 5:34 pm #6492
      Thomas Barth
      Participant

      Martin,

       

      Remember the setup you used for an example is pretty close to the same as far as main jetting is concerned. One needle has 1.50mm tip the other a 1.80. but the different main jetting compensates for difference in needle tips.

  • Author
    Posts
Viewing 7 reply threads
  • You must be logged in to reply to this topic.