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  4. Whats a good carburetor for my DT125 with a 170cc athena cylinder kit?

Whats a good carburetor for my DT125 with a 170cc athena cylinder kit?

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carburetor
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  • DartyD Darty

    @claws alt text

    Not to sound boring, but, Keihin PWK 36mm of a KDX220

    Been there done that, mental, makes no sense. Actually slower overall..

    A 32mm can be spot on, if you like to 'hoon' constantly, but these engines are fussy to jet on a bigger carb, I don't recommend it.

    clawsC Offline
    clawsC Offline
    claws
    wrote on last edited by
    #17

    @Darty cant be slower than now though

    2̶0̶0̶4̶ ̶D̶T̶1̶2̶5̶R̶E̶ ̶w̶i̶t̶h̶ ̶s̶u̶p̶e̶r̶m̶o̶t̶o̶ ̶w̶h̶e̶e̶l̶s̶ ̶a̶n̶d̶ ̶a̶ ̶1̶7̶0̶c̶c̶ ̶a̶t̶h̶e̶n̶a̶ ̶k̶i̶t̶
    1999 YZ250 with a 1999 DTR VIN

    CalumC DartyD 2 Replies Last reply
    0
    • clawsC claws

      @Darty cant be slower than now though

      CalumC Offline
      CalumC Offline
      Calum
      wrote on last edited by
      #18

      @claws You'd be surprised.

      I'm not going into the specifics.

      But Pressure=force/area

      The force is generated via the vacuum of the engine, the area is the size of the carb.

      If the carb increases sizes, but the vacuum remains the same then you will see a drop in pressure. Aka, the pressure to actuate the carb will lower and it may not be as effective, sine the carb works off the venturi effect, getting this balance right is important. Going too big can have adverse affects. Is 36mm too big? I'm not saying that, I'm just saying bigger is not always better.

      Always Originate, Never Pirate!

      clawsC 1 Reply Last reply
      1
      • CalumC Calum

        @claws You'd be surprised.

        I'm not going into the specifics.

        But Pressure=force/area

        The force is generated via the vacuum of the engine, the area is the size of the carb.

        If the carb increases sizes, but the vacuum remains the same then you will see a drop in pressure. Aka, the pressure to actuate the carb will lower and it may not be as effective, sine the carb works off the venturi effect, getting this balance right is important. Going too big can have adverse affects. Is 36mm too big? I'm not saying that, I'm just saying bigger is not always better.

        clawsC Offline
        clawsC Offline
        claws
        wrote on last edited by
        #19

        @Calum of course a bigger carburetor isnt always better but i dont think that i can go slower with the keihin and if i cant get it to run great with the bike i will trade it for a smaller one. but a guy that i know put a 38mm carb in his 1998 dt125r and said that it runs great. still i believe that the new carburetor will out perform the one i have now but if it doesnt i will be a bit disappointed but anyways i wont lose anything with this new carb

        2̶0̶0̶4̶ ̶D̶T̶1̶2̶5̶R̶E̶ ̶w̶i̶t̶h̶ ̶s̶u̶p̶e̶r̶m̶o̶t̶o̶ ̶w̶h̶e̶e̶l̶s̶ ̶a̶n̶d̶ ̶a̶ ̶1̶7̶0̶c̶c̶ ̶a̶t̶h̶e̶n̶a̶ ̶k̶i̶t̶
        1999 YZ250 with a 1999 DTR VIN

        1 Reply Last reply
        0
        • CalumC Offline
          CalumC Offline
          Calum
          wrote on last edited by
          #20

          Oh yeah! Report back to us your findings 😃

          Always Originate, Never Pirate!

          1 Reply Last reply
          1
          • clawsC claws

            @Darty cant be slower than now though

            DartyD Offline
            DartyD Offline
            Darty
            wrote on last edited by Darty
            #21

            @claws True, but don't forget you'll make less power under 6-8k Rpm.

            @Calum lol I don't have much to say about these bikes anymore

            Keep it real

            clawsC CalumC declanD NINJAN 4 Replies Last reply
            1
            • DartyD Darty

              @claws True, but don't forget you'll make less power under 6-8k Rpm.

              @Calum lol I don't have much to say about these bikes anymore

              clawsC Offline
              clawsC Offline
              claws
              wrote on last edited by
              #22

              @Darty doesnt matter. it doesnt have much torque in the lower rpms but its because my ypvs is locked to the up right position. gonna get it resolved as well and maybe get an athena pipe for the bike since its made for the 170cc cylinder kit

              2̶0̶0̶4̶ ̶D̶T̶1̶2̶5̶R̶E̶ ̶w̶i̶t̶h̶ ̶s̶u̶p̶e̶r̶m̶o̶t̶o̶ ̶w̶h̶e̶e̶l̶s̶ ̶a̶n̶d̶ ̶a̶ ̶1̶7̶0̶c̶c̶ ̶a̶t̶h̶e̶n̶a̶ ̶k̶i̶t̶
              1999 YZ250 with a 1999 DTR VIN

              1 Reply Last reply
              0
              • Glynn123G Offline
                Glynn123G Offline
                Glynn123
                wrote on last edited by
                #23

                Jetting a none standard carb on a DT is a ballache, 32mm polini pwk didn't make my DT much faster at all without any supporting mods like ignition etc. The fuel usage was well over double too even with both carbs appropriately jetted.

                1 Reply Last reply
                0
                • DartyD Darty

                  @claws True, but don't forget you'll make less power under 6-8k Rpm.

                  @Calum lol I don't have much to say about these bikes anymore

                  CalumC Offline
                  CalumC Offline
                  Calum
                  wrote on last edited by
                  #24

                  @Darty Join the club. But most of us talk about different projects these days.

                  Always Originate, Never Pirate!

                  clawsC 1 Reply Last reply
                  0
                  • DartyD Darty

                    @claws True, but don't forget you'll make less power under 6-8k Rpm.

                    @Calum lol I don't have much to say about these bikes anymore

                    declanD Offline
                    declanD Offline
                    declan
                    wrote on last edited by
                    #25

                    @Darty we kinda miss ya around here

                    1 Reply Last reply
                    1
                    • DartyD Darty

                      @claws True, but don't forget you'll make less power under 6-8k Rpm.

                      @Calum lol I don't have much to say about these bikes anymore

                      NINJAN Offline
                      NINJAN Offline
                      NINJA
                      wrote on last edited by
                      #26

                      @Darty Which bikes are you currently working on/involved with ATM then dude???

                      SEDUCED BY THE DARK SIDE!!!

                      1 Reply Last reply
                      0
                      • CalumC Calum

                        @Darty Join the club. But most of us talk about different projects these days.

                        clawsC Offline
                        clawsC Offline
                        claws
                        wrote on last edited by
                        #27

                        @Calum okay so the carb made the dt much better. didnt even have to tune it lol

                        2̶0̶0̶4̶ ̶D̶T̶1̶2̶5̶R̶E̶ ̶w̶i̶t̶h̶ ̶s̶u̶p̶e̶r̶m̶o̶t̶o̶ ̶w̶h̶e̶e̶l̶s̶ ̶a̶n̶d̶ ̶a̶ ̶1̶7̶0̶c̶c̶ ̶a̶t̶h̶e̶n̶a̶ ̶k̶i̶t̶
                        1999 YZ250 with a 1999 DTR VIN

                        1 Reply Last reply
                        0
                        • clawsC Offline
                          clawsC Offline
                          claws
                          wrote on last edited by
                          #28

                          and i flipped the bike while doing a wheelie today. bent my front forks and got the rear plastic banged up. getting new ones tomorrow though

                          2̶0̶0̶4̶ ̶D̶T̶1̶2̶5̶R̶E̶ ̶w̶i̶t̶h̶ ̶s̶u̶p̶e̶r̶m̶o̶t̶o̶ ̶w̶h̶e̶e̶l̶s̶ ̶a̶n̶d̶ ̶a̶ ̶1̶7̶0̶c̶c̶ ̶a̶t̶h̶e̶n̶a̶ ̶k̶i̶t̶
                          1999 YZ250 with a 1999 DTR VIN

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