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    YAMAHA DT 125 E SWISS

    Derestricting
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    • DylanDT219
      DylanDT219 last edited by

      Good evening everyone, I'm new to this forum my name is Dylan and I currently live in Switzerland, for 2 years I bought my bike or the DT 125 R (1991) of yamaha but I have a problem with it, the bike is currently mounting the group thermal 170cc athena New with less than 1'000km, athena firebox exhaust and 30mm mikuni carburetor (the carburetion of the bike is perfect, the spark plug is hazelnut brown) and everything else is original. Basically my problem is that my bike does not exceed 80km / h and I don't know why (the YPVS has already turned 180 degrees but ah just gave me more recovery and that's it) ... a guy on facebook says that mine motor (3ME) since it is Swiss and heavily restricted both mechanically and electronically and I honestly do not know where to put my hand ... someone who knows more and help me? ...

      P.S If I have missed something, please ask

      P.S.S This text was translated by google translator so sorry if there are mistakes but unfortunately english is not my mother tongue

      declan 1 Reply Last reply Reply Quote 0
      • declan
        declan @DylanDT219 last edited by

        @DylanDT219 http://www.scrimsmustangclassicyamahadtrestoration.com/derestricting-the-yamaha-dt125r-1988-through-to-2007.html

        DylanDT219 1 Reply Last reply Reply Quote 0
        • Calum
          Calum last edited by

          I thought the 91 models were pretty good.

          You'd ideally want the powervalve servo operated, but spinning 180 degrees doesn't mean much to me. Where did you spin it 180 from.

          My advice would be to follow the derestriction guide, either connect the valve up properly or pin it so it's flush with the exhaust port.

          The easiest way to derestrict all of your restrictions would be to grab an aftermarket ignition system like the Zeeltronic. Your mechanical restrictions won't exist if you don't have the stock pipe and/or head. So it'll just be the CDI.

          Always Originate, Never Pirate!

          DylanDT219 1 Reply Last reply Reply Quote 1
          • DylanDT219
            DylanDT219 @declan last edited by

            @declan already seen and I don't need it since as I said my muffler has already been changed with a modified one

            1 Reply Last reply Reply Quote 0
            • DylanDT219
              DylanDT219 @Calum last edited by DylanDT219

              @Calum I went to the Zeeltronic website but I did not find the model of my engine or 3ME but I also think I am the cdi because I read it on another forum -> '' ... since the Swiss had a limited 4HX CDI for the their market ... ''

              P.S then for the 180 degree I found this info on some site and then I actually did it as I said it worked but not for the maximum speed which always remained at 80km / h

              Darty 1 Reply Last reply Reply Quote 0
              • Darty
                Darty @DylanDT219 last edited by

                @DylanDT219 You need to check the crankcase serial number, which for a 91, will most likely be a 4BL - 000

                Keep it real

                DylanDT219 1 Reply Last reply Reply Quote 0
                • DylanDT219
                  DylanDT219 @Darty last edited by DylanDT219

                  @Darty mine is 3ME-0007 if you want i can send to you a photo

                  Calum 1 Reply Last reply Reply Quote 0
                  • Calum
                    Calum @DylanDT219 last edited by

                    @DylanDT219 don't focus on 180 degree stuff. Whip the exhaust off and make sure the powervalve is flush with the exhaust port when the valve opens fully. To test the top end you can pin it open and disconnect the valve.

                    Always Originate, Never Pirate!

                    DylanDT219 2 Replies Last reply Reply Quote 0
                    • DylanDT219
                      DylanDT219 @Calum last edited by

                      This post is deleted!
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                      • DylanDT219
                        DylanDT219 @Calum last edited by

                        @Calum
                        okay let's say my valve is perfectly adjusted what should I do? change cdi? if so with which one?

                        Calum 1 Reply Last reply Reply Quote 0
                        • Calum
                          Calum @DylanDT219 last edited by

                          @DylanDT219 Make sure the inlet and exhaust tracts are free from restrictions. Ensure the linked above derestrictions are in place and make sure the engine is healthy.

                          Is the bike using stock gearing?

                          Always Originate, Never Pirate!

                          DylanDT219 1 Reply Last reply Reply Quote 0
                          • DylanDT219
                            DylanDT219 @Calum last edited by

                            @Calum maybe you still have not understood the sport exhaust and it is no longer original I have mounted ujna firebox athena in addition to this on the site we wrote that inlet before 1991 there are no restrictions and then I do not know if the gearbox is original since I have never opened the engine and then I do not think that there are modified changes for the dtr

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                            • Calum
                              Calum last edited by

                              By restrictions mate, I mean blockages. Like is there leaves and dirt in the inlet tract. As well as exhaust. So yes it may be an aftermarket exhaust, but if it's blocked then that will cause poor performance.

                              And by stock gearing, I mean the front and rear sprockets.

                              Sorry for the confusion.

                              Always Originate, Never Pirate!

                              DylanDT219 1 Reply Last reply Reply Quote 0
                              • S
                                SpookDog last edited by

                                ‘Lost in translation’ springs to mind...

                                How long has your bike been stuck at 80kph? (60 mph is slow and wrong)
                                Was it faster before? Has it always been so since tha 170 Athena kit? Did it come as a 170? More history is needed...

                                Hazelnut brown is too dark, no?. Should be ‘tan’ ideally?? Been a while since I’ve had my last stroke (2) ☠️

                                DylanDT219 1 Reply Last reply Reply Quote 0
                                • Calum
                                  Calum last edited by

                                  Even if the fueling was slightly off it should be better than that. That said the Athena kit is a bit shite.

                                  Always Originate, Never Pirate!

                                  1 Reply Last reply Reply Quote 0
                                  • DylanDT219
                                    DylanDT219 @Calum last edited by

                                    @Calum
                                    ahhh okay anyway stock gearing for dirt don't worry i checked and it's all clean

                                    1 Reply Last reply Reply Quote 0
                                    • DylanDT219
                                      DylanDT219 @SpookDog last edited by

                                      @SpookDog my bike has always been blocked both with the original cylinder and with the 170cc it has always done less than 80 km / h. the 170cc arrived new from a german site with everything you need i still have the box ...

                                      declan 1 Reply Last reply Reply Quote 0
                                      • declan
                                        declan @DylanDT219 last edited by

                                        This post is deleted!
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                                        • S
                                          SpookDog last edited by

                                          If it’s the same with two different cylinders and exhausts it is obviously something else. Either the carb or ignition.
                                          What does it max out at on revs?
                                          Does it rev up smoothly?

                                          DylanDT219 1 Reply Last reply Reply Quote 0
                                          • DylanDT219
                                            DylanDT219 @SpookDog last edited by

                                            @SpookDog you rev ​​up without problems, before I turned the YPVS by 180 ° it reached a maximum of 8 thousand rpm, but anyway this is the problem here someone has to tell me if they know any mechanical block so inside or outside the engine and electronically

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