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DT125R FORUM

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  3. Welcome New Owners!
  4. New purchase 1990 dt125r

New purchase 1990 dt125r

Scheduled Pinned Locked Moved Welcome New Owners!
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  • O Offline
    O Offline
    oldman
    wrote on last edited by
    #20

    Here's one I prepared earlier !
    0_1502570553952_20170715_131805.jpg

    U 1 Reply Last reply
    0
    • U Offline
      U Offline
      ukchad
      wrote on last edited by
      #21

      Is it normal for the exhaust to heat up so much then, when the power valve is fully open?

      Also died a bit when I kicked up into 6th, ran out of power (maybe wasn't high enough revs)

      declanD 1 Reply Last reply
      0
      • O oldman

        Here's one I prepared earlier !
        0_1502570553952_20170715_131805.jpg

        U Offline
        U Offline
        ukchad
        wrote on last edited by
        #22

        @oldman soooo clean

        1 Reply Last reply
        0
        • U ukchad

          Is it normal for the exhaust to heat up so much then, when the power valve is fully open?

          Also died a bit when I kicked up into 6th, ran out of power (maybe wasn't high enough revs)

          declanD Offline
          declanD Offline
          declan
          wrote on last edited by
          #23

          @ukchad coming from 4 stroke this was crazy for me I have full functioning pv) my muffler gets too hot to touch

          1 Reply Last reply
          0
          • terry.tzT terry.tz

            @declan coming on that is Declan

            declanD Offline
            declanD Offline
            declan
            wrote on last edited by
            #24

            @terry-tz hey thank you buddy nice hearing that much appreciated but a lot to go yet 😊

            terry.tzT 1 Reply Last reply
            0
            • declanD declan

              @terry-tz hey thank you buddy nice hearing that much appreciated but a lot to go yet 😊

              terry.tzT Offline
              terry.tzT Offline
              terry.tz
              wrote on last edited by
              #25

              @declan good to know there's more to come

              "Muddy water is best cleared by leaving it alone" Alan Watts

              1 Reply Last reply
              0
              • CalumC Offline
                CalumC Offline
                Calum
                wrote on last edited by
                #26

                Hello and welcome'

                Get the servo retro fitted and have a working powervalve. Best of both worlds.

                Exhaust gets hotter because you spend longer times at higher rpms. Refer back to my previous statement. Get the servo fitted. Less stress on the engine.

                I would start simple first, check the thermostat, they are probe to failing after zo many years.

                Head gasket is not the same as a four stroke. No valves no nothing to go wrong.

                Buy only genuine or athena gasket, skim the head like described in my tutorial, then boom, good to go.

                Nice bike.

                Always Originate, Never Pirate!

                declanD U 2 Replies Last reply
                0
                • MiniaM Offline
                  MiniaM Offline
                  Minia
                  wrote on last edited by
                  #27

                  Welcome, looking good 🙂

                  Yamaha DT125R Blue 2002, XT 125 1982, Yamaha WR250Z 1992, BMW GS650F 1994, Benelli BN302 2015

                  1 Reply Last reply
                  0
                  • CalumC Calum

                    Hello and welcome'

                    Get the servo retro fitted and have a working powervalve. Best of both worlds.

                    Exhaust gets hotter because you spend longer times at higher rpms. Refer back to my previous statement. Get the servo fitted. Less stress on the engine.

                    I would start simple first, check the thermostat, they are probe to failing after zo many years.

                    Head gasket is not the same as a four stroke. No valves no nothing to go wrong.

                    Buy only genuine or athena gasket, skim the head like described in my tutorial, then boom, good to go.

                    Nice bike.

                    declanD Offline
                    declanD Offline
                    declan
                    wrote on last edited by
                    #28

                    @calum what's skimming the head do I know squish and compression etc but does just that on its own yield noticeable results?

                    1 Reply Last reply
                    0
                    • U ukchad

                      Hello everyone,
                      Just brought myself a DT125R.
                      Always wanted one since I was knocking around at 15 on my CB125 - finally got the cash to treat myself.

                      Found on EBay
                      UK registered from new, engine and frame numbers match.

                      Bit scruffy, but perfect for me to fiddle around with at the weekends

                      0_1502565963724_IMG_2819.JPG

                      Not sure if I loaded the photo properly!

                      Plenty of tidying to be done on the bike, electrics, decals, plastics, tank etc etc, but looking forward to it and coming here for advice!

                      NINJAN Offline
                      NINJAN Offline
                      NINJA
                      wrote on last edited by
                      #29

                      @ukchad Welcome aboard, looks like you have a decent starting point there. 👍

                      SEDUCED BY THE DARK SIDE!!!

                      1 Reply Last reply
                      0
                      • CalumC Calum

                        Hello and welcome'

                        Get the servo retro fitted and have a working powervalve. Best of both worlds.

                        Exhaust gets hotter because you spend longer times at higher rpms. Refer back to my previous statement. Get the servo fitted. Less stress on the engine.

                        I would start simple first, check the thermostat, they are probe to failing after zo many years.

                        Head gasket is not the same as a four stroke. No valves no nothing to go wrong.

                        Buy only genuine or athena gasket, skim the head like described in my tutorial, then boom, good to go.

                        Nice bike.

                        U Offline
                        U Offline
                        ukchad
                        wrote on last edited by
                        #30

                        @calum so I think I understand.

                        At the moment the power valve either works at low down or higher revs because it is fixed in position?
                        I choose that position by turning 180 degrees either way?
                        By fitting a servo, the power valve is rotated to give me full power depending on revs.
                        Is this correct?

                        My power valve doesn't look like most i see in pictures - no cables or slots for cables in the casing. Just a central bolt, flanked by 2 small outer bolts

                        Can a servo still be retro fitted to this?

                        1 Reply Last reply
                        1
                        • NottsbikerN Offline
                          NottsbikerN Offline
                          Nottsbiker
                          wrote on last edited by
                          #31

                          Yes you are missing the cables, servo, cable housing, cover and pulley.

                          You can get these from any DTR or TDR and they will fit your bike. Not sure on servo motor but i think any DT one can be adapted to fit

                          1 Reply Last reply
                          0
                          • U Offline
                            U Offline
                            ukchad
                            wrote on last edited by
                            #32

                            Thanks @Nottsbiker

                            If any one knows, finds or has one that fits please bear me in mind.

                            I can then start a build thread and you can all watch me mess it up!

                            1 Reply Last reply
                            0
                            • NottsbikerN Offline
                              NottsbikerN Offline
                              Nottsbiker
                              wrote on last edited by
                              #33

                              Think you and i will be after m the same vintage servo motors 😉

                              Don't out bid me on any lol

                              1 Reply Last reply
                              0
                              • U Offline
                                U Offline
                                ukchad
                                wrote on last edited by
                                #34

                                Let me know, and we can make sure!

                                1 Reply Last reply
                                0
                                • A Offline
                                  A Offline
                                  andrewj1680
                                  wrote on last edited by
                                  #35

                                  The powervalve is different you would have to change the whole lot in my opinion its not worth it the servo takes the fun out of it anyway

                                  declanD 1 Reply Last reply
                                  0
                                  • A andrewj1680

                                    The powervalve is different you would have to change the whole lot in my opinion its not worth it the servo takes the fun out of it anyway

                                    declanD Offline
                                    declanD Offline
                                    declan
                                    wrote on last edited by
                                    #36

                                    @andrewj1680 0_1502635173746_IMG_1500.JPG

                                    Any idea what that yellow and black wire does that goes to the powervalve servo it turns using the key still?

                                    1 Reply Last reply
                                    0
                                    • A Offline
                                      A Offline
                                      andrewj1680
                                      wrote on last edited by
                                      #37

                                      At a guess mate that 1 sends signal from the cdi unit, have you tried riding the bike to see if it still cuts in?

                                      declanD 2 Replies Last reply
                                      0
                                      • A andrewj1680

                                        At a guess mate that 1 sends signal from the cdi unit, have you tried riding the bike to see if it still cuts in?

                                        declanD Offline
                                        declanD Offline
                                        declan
                                        wrote on last edited by
                                        #38

                                        @andrewj1680 on it right now and no decent seem to be and it always lands on the open position crazy how much different the bike sounds when it's open

                                        1 Reply Last reply
                                        1
                                        • A andrewj1680

                                          At a guess mate that 1 sends signal from the cdi unit, have you tried riding the bike to see if it still cuts in?

                                          declanD Offline
                                          declanD Offline
                                          declan
                                          wrote on last edited by declan
                                          #39

                                          @andrewj1680 love it it's actually use able at low speed now but my idle has gone up to 2.5 when I'm gear in neutral it drops back down to a slow 1.5 any reason for this?

                                          1 Reply Last reply
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