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DT125R FORUM

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  4. Yamaha DT 125 DERESTRICTING

Yamaha DT 125 DERESTRICTING

Scheduled Pinned Locked Moved Derestricting
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  • markus.wM markus.w

    @Lukas55 it is hard to see the picture but it looks to me that just under the Speedo cable connector is the place where the reed switch was, maybe it's there but the wires are not. Try tracing the wires back it may be tucked away somewhere if it's already been done or you may just find the wires had been cut with no reed switch on the end of them (it looks like a glass fuse or bulb) now I understand they shouldn't be cut off because it could cause you problems with the way it runs so maybe that is your problem.

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    Lukas55
    wrote on last edited by
    #13

    @markus-w Thats what I thought, but there is no slot or anything where reed switch could be...
    This is how it looks:

    [url=https://postimg.cc/7J0LL548][img]https://i.postimg.cc/7J0LL548/IMG-20200922-181715.jpg[/img][/url]

    [url=https://postimg.cc/pmpL9cRJ][img]https://i.postimg.cc/pmpL9cRJ/IMG-20200922-181721.jpg[/img][/url]

    [url=https://postimg.cc/FkZ2Gvgk][img]https://i.postimg.cc/FkZ2Gvgk/IMG-20200922-181728.jpg[/img][/url]

    [url=https://postimg.cc/vDsTPvtG][img]https://i.postimg.cc/vDsTPvtG/IMG-20200922-181733.jpg[/img][/url]

    That means there must be some cable but obviously its not black/green because someone changed wires and made mess...
    Like there is no white block where wires are supposed to go...It looks like this:

    [url=https://postimg.cc/pmtsr4Dg][img]https://i.postimg.cc/pmtsr4Dg/IMG-20200922-193040.jpg[/img][/url]

    [url=https://postimg.cc/RJHTVLqS][img]https://i.postimg.cc/RJHTVLqS/IMG-20200922-193042.jpg[/img][/url]

    [url=https://postimg.cc/CBtNgQhr][img]https://i.postimg.cc/CBtNgQhr/IMG-20200922-193103.jpg[/img][/url]

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    • L Lukas55

      @markus-w Thats what I thought, but there is no slot or anything where reed switch could be...
      This is how it looks:

      [url=https://postimg.cc/7J0LL548][img]https://i.postimg.cc/7J0LL548/IMG-20200922-181715.jpg[/img][/url]

      [url=https://postimg.cc/pmpL9cRJ][img]https://i.postimg.cc/pmpL9cRJ/IMG-20200922-181721.jpg[/img][/url]

      [url=https://postimg.cc/FkZ2Gvgk][img]https://i.postimg.cc/FkZ2Gvgk/IMG-20200922-181728.jpg[/img][/url]

      [url=https://postimg.cc/vDsTPvtG][img]https://i.postimg.cc/vDsTPvtG/IMG-20200922-181733.jpg[/img][/url]

      That means there must be some cable but obviously its not black/green because someone changed wires and made mess...
      Like there is no white block where wires are supposed to go...It looks like this:

      [url=https://postimg.cc/pmtsr4Dg][img]https://i.postimg.cc/pmtsr4Dg/IMG-20200922-193040.jpg[/img][/url]

      [url=https://postimg.cc/RJHTVLqS][img]https://i.postimg.cc/RJHTVLqS/IMG-20200922-193042.jpg[/img][/url]

      [url=https://postimg.cc/CBtNgQhr][img]https://i.postimg.cc/CBtNgQhr/IMG-20200922-193103.jpg[/img][/url]

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      DTR+NSR
      wrote on last edited by
      #14

      @Lukas55 you first need to work out what model of dtr you have, it looks like it could be a bitsa'. Be worth looking to see what markings are on the cdi and wether it has a 3 or 5 wire power valve servo.

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      • D DTR+NSR

        @Lukas55 you first need to work out what model of dtr you have, it looks like it could be a bitsa'. Be worth looking to see what markings are on the cdi and wether it has a 3 or 5 wire power valve servo.

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        Lukas55
        wrote on last edited by
        #15

        @DTR-NSR I am not sure but I think that 3 wires are coming out of servo...Markings on CDI are a little bit erased so it is not clear what does it say...
        https://i.postimg.cc/vDXz2TwH/cc.jpg
        https://i.postimg.cc/NK2k0x95/ccccc.jpg
        https://i.postimg.cc/ns8Y9QBT/cdi.jpg
        https://i.postimg.cc/RNDT9Y0k/cdii.jpg

        Btw what is bitsa'?

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        • L Lukas55

          @DTR-NSR I am not sure but I think that 3 wires are coming out of servo...Markings on CDI are a little bit erased so it is not clear what does it say...
          https://i.postimg.cc/vDXz2TwH/cc.jpg
          https://i.postimg.cc/NK2k0x95/ccccc.jpg
          https://i.postimg.cc/ns8Y9QBT/cdi.jpg
          https://i.postimg.cc/RNDT9Y0k/cdii.jpg

          Btw what is bitsa'?

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          DTR+NSR
          wrote on last edited by
          #16

          @Lukas55 bitsa = bike made up from parts from several different bikes.
          It sounds like your bike might have early wiring and cdi. I'd be checking the powervalve is in the open position and the exhaust has had the restrictions removed if it's a original yamaha one. Hard to make out much out from your pics.

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            Lukas55
            wrote on last edited by
            #17

            @DTR-NSR Yea I know pictures are not great but I can not even see better with my eyes xD. It has some different exhaust I would say that it have yz 125 silincer... Okay so if the black/green wire is going into the speedo it must come from somewhere...

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              Lukas55
              wrote on last edited by
              #18

              Btw that is 3MB cdi.

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              • L Lukas55

                Btw that is 3MB cdi.

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                DTR+NSR
                wrote on last edited by
                #19

                @Lukas55 the black green wire comes from the cdi, but your bike will not have the black green wire. It's only found on later bikes 2004/5 onwards. I've got a feeling yours is running about 1998 wiring and cdi. The restrictions in the exhaust are in the front expansion chamber part.

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                • D DTR+NSR

                  @Lukas55 the black green wire comes from the cdi, but your bike will not have the black green wire. It's only found on later bikes 2004/5 onwards. I've got a feeling yours is running about 1998 wiring and cdi. The restrictions in the exhaust are in the front expansion chamber part.

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                  Lukas55
                  wrote on last edited by
                  #20

                  @DTR-NSR So it has only exhaust restriction?

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                    Lukas55
                    wrote on last edited by
                    #21

                    Here is video of power valve, maybe its something wrong with it... If video quality is bad I will make better one tomorrow...
                    https://youtu.be/naA3Zt0piGs

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                    • L Lukas55

                      Here is video of power valve, maybe its something wrong with it... If video quality is bad I will make better one tomorrow...
                      https://youtu.be/naA3Zt0piGs

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                      DTR+NSR
                      wrote on last edited by
                      #22

                      @Lukas55 the powervalve seems to operate as expected. It'd be worth taking the exhaust off to see if the valve is in the open position when it's supposed to be. It can be fitted 180° out. And to check there's no restrict ions in the exhuast it self.

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                      • D DTR+NSR

                        @Lukas55 the powervalve seems to operate as expected. It'd be worth taking the exhaust off to see if the valve is in the open position when it's supposed to be. It can be fitted 180° out. And to check there's no restrict ions in the exhuast it self.

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                        Lukas55
                        wrote on last edited by
                        #23

                        @DTR-NSR I will check that tomorrow. One more question, so is there any chance of putting different CDI with higher rev limiter?

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                        • L Lukas55

                          @DTR-NSR I will check that tomorrow. One more question, so is there any chance of putting different CDI with higher rev limiter?

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                          DTR+NSR
                          wrote on last edited by
                          #24

                          @Lukas55 yours looks to have a earlier cdi which are considered the best.

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                          • D DTR+NSR

                            @Lukas55 yours looks to have a earlier cdi which are considered the best.

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                            Lukas55
                            wrote on last edited by
                            #25

                            @DTR-NSR Hmmm okay, that's great. It tops at 5500 rpms in 6 gear so it must be because of exhaust...

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                            • S Offline
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                              SpookDog
                              wrote on last edited by
                              #26

                              In my opinion, If it’s only doing 50mph, it’s not because of restrictions, it’s cause there is something wrong with it...
                              How long have you had the bike? Has it always been so slow? It might just be rebuilding time...

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                              • L Offline
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                                Lukas55
                                wrote on last edited by
                                #27

                                I have it for about 3 months and it was like that when I bought it. It had 13-57 gearing so I thought it's because of that but when I bought 16t front sprocket then I noticed it's something wrong... The piston and bearings in the crankshaft are changed 400km ago...

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                                • L Offline
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                                  Lukas55
                                  wrote on last edited by
                                  #28

                                  I removed the exhaust and the piston looks like this...
                                  https://i.postimg.cc/Bj4tBnD6/adw.jpg
                                  https://i.postimg.cc/xcrXqR1L/daw.jpg
                                  https://i.postimg.cc/ykFkRZDt/daws.jpg

                                  Btw is YVPS set good? Is it supposed to look like that in the cylinder?

                                  declanD 1 Reply Last reply
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                                  • L Lukas55

                                    I removed the exhaust and the piston looks like this...
                                    https://i.postimg.cc/Bj4tBnD6/adw.jpg
                                    https://i.postimg.cc/xcrXqR1L/daw.jpg
                                    https://i.postimg.cc/ykFkRZDt/daws.jpg

                                    Btw is YVPS set good? Is it supposed to look like that in the cylinder?

                                    declanD Offline
                                    declanD Offline
                                    declan
                                    wrote on last edited by
                                    #29

                                    @Lukas55 looks like the ypvs can be set better did you have proof that the piston was changed

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                                    • declanD declan

                                      @Lukas55 looks like the ypvs can be set better did you have proof that the piston was changed

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                                      Lukas55
                                      wrote on last edited by
                                      #30

                                      @declan
                                      No ... Very stupid mistake, Next time I'll take off the exhaust to check ...Never can't trust people I guess.

                                      declanD 1 Reply Last reply
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                                      • L Lukas55

                                        @declan
                                        No ... Very stupid mistake, Next time I'll take off the exhaust to check ...Never can't trust people I guess.

                                        declanD Offline
                                        declanD Offline
                                        declan
                                        wrote on last edited by
                                        #31

                                        @Lukas55 the piston doesn't look too bad just doubt it was changed

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                                        • declanD declan

                                          @Lukas55 the piston doesn't look too bad just doubt it was changed

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                                          DTR+NSR
                                          wrote on last edited by
                                          #32

                                          Does it rev higher in the other gears? The powervalve looks ok.

                                          1 Reply Last reply
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