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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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  • CalumC Offline
    CalumC Offline
    Calum
    wrote on last edited by
    #4

    36 is HUGE!

    that will be horrendous on fuel!

    Always Originate, Never Pirate!

    clawsC 1 Reply Last reply
    0
    • CalumC Calum

      36 is HUGE!

      that will be horrendous on fuel!

      clawsC Offline
      clawsC Offline
      claws
      wrote on last edited by
      #5

      @Calum it is already because my ypvs is locked to the up right position and the carburetor isnt in perfect tune

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

      CalumC 1 Reply Last reply
      0
      • clawsC claws

        @Calum it is already because my ypvs is locked to the up right position and the carburetor isnt in perfect tune

        CalumC Offline
        CalumC Offline
        Calum
        wrote on last edited by
        #6

        @claws Well you've definitely got more money than me.

        Once upon a time my brother ran a kehien 38 on his 170 Athena. The fueling was mental and the performance did not match.

        That's just my advice, you don't have to take it. Bigger is not always better. You'd do well to lower it to get more performance and fuel economy.

        My brother is currently running a 34mm on a 170cc two stroke, and he's looking at a 28mm for more performance and better economy.

        Always Originate, Never Pirate!

        clawsC 1 Reply Last reply
        0
        • CalumC Calum

          @claws Well you've definitely got more money than me.

          Once upon a time my brother ran a kehien 38 on his 170 Athena. The fueling was mental and the performance did not match.

          That's just my advice, you don't have to take it. Bigger is not always better. You'd do well to lower it to get more performance and fuel economy.

          My brother is currently running a 34mm on a 170cc two stroke, and he's looking at a 28mm for more performance and better economy.

          clawsC Offline
          clawsC Offline
          claws
          wrote on last edited by
          #7

          @Calum i cant really tune my current carb and i dont have that much money haha

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

          CalumC 1 Reply Last reply
          0
          • clawsC claws

            @Calum i cant really tune my current carb and i dont have that much money haha

            CalumC Offline
            CalumC Offline
            Calum
            wrote on last edited by
            #8

            @claws You're throwing good money after bad, a few jets is considerably cheaper than a 36mm carb. Besides, do you really think slapping on a carb will make your bike run right?

            Fueling is no something you scrimp on, run it lean, and you'll run into detonation destroying both the bottom and top end. So don't scrimp on fueling.

            Always Originate, Never Pirate!

            clawsC 1 Reply Last reply
            1
            • CalumC Calum

              @claws You're throwing good money after bad, a few jets is considerably cheaper than a 36mm carb. Besides, do you really think slapping on a carb will make your bike run right?

              Fueling is no something you scrimp on, run it lean, and you'll run into detonation destroying both the bottom and top end. So don't scrimp on fueling.

              clawsC Offline
              clawsC Offline
              claws
              wrote on last edited by
              #9

              @Calum getting the keihin for 60 euros isnt a bad deal besides the screws for the carburetor are seized so i cant mess with the float or jets. also i can just sell the carb if i need to. im not an expert at tuning carbs but i can make it run ok

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

              CalumC 1 Reply Last reply
              0
              • clawsC claws

                @Calum getting the keihin for 60 euros isnt a bad deal besides the screws for the carburetor are seized so i cant mess with the float or jets. also i can just sell the carb if i need to. im not an expert at tuning carbs but i can make it run ok

                CalumC Offline
                CalumC Offline
                Calum
                wrote on last edited by
                #10

                @claws It needs to run spot on, is my point. Even the new carb will need jetting.

                Always Originate, Never Pirate!

                O clawsC 2 Replies Last reply
                1
                • CalumC Calum

                  @claws It needs to run spot on, is my point. Even the new carb will need jetting.

                  O Offline
                  O Offline
                  oldman
                  wrote on last edited by
                  #11

                  @Calum said in Whats a good carburetor for my DT125 with a 170cc athena cylinder kit?:

                  @claws It needs to run spot on, is my point. Even the new carb will need jetting.

                  I second that

                  1 Reply Last reply
                  0
                  • CalumC Calum

                    @claws It needs to run spot on, is my point. Even the new carb will need jetting.

                    clawsC Offline
                    clawsC Offline
                    claws
                    wrote on last edited by
                    #12

                    @Calum gonna get it running great. better than with the original carb

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

                    CalumC 1 Reply Last reply
                    1
                    • clawsC claws

                      @Calum gonna get it running great. better than with the original carb

                      CalumC Offline
                      CalumC Offline
                      Calum
                      wrote on last edited by Calum
                      #13

                      @claws That's great to hear! I know from experience going too big is detrimental. But maybe I didn't spend enough time tweaking it!

                      Always Originate, Never Pirate!

                      clawsC 1 Reply Last reply
                      0
                      • CalumC Calum

                        @claws That's great to hear! I know from experience going too big is detrimental. But maybe I didn't spend enough time tweaking it!

                        clawsC Offline
                        clawsC Offline
                        claws
                        wrote on last edited by
                        #14

                        @Calum wouldnt be making any sense to not get it running great. gonna send a video of it running later

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

                        DartyD 1 Reply Last reply
                        0
                        • clawsC claws

                          @Calum wouldnt be making any sense to not get it running great. gonna send a video of it running later

                          DartyD Offline
                          DartyD Offline
                          Darty
                          wrote on last edited by
                          #15

                          @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.

                          Keep it real

                          CalumC clawsC 2 Replies Last reply
                          3
                          • 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.

                            CalumC Offline
                            CalumC Offline
                            Calum
                            wrote on last edited by
                            #16

                            @Darty Long time no post 😛

                            Always Originate, Never Pirate!

                            1 Reply Last reply
                            0
                            • 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
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