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DT125R FORUM

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Lapping

Scheduled Pinned Locked Moved Top End
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  • BluestoesonnoseB Offline
    BluestoesonnoseB Offline
    Bluestoesonnose
    wrote on last edited by
    #3

    LC motors are alloy and it seems to be a wide spread practice with the aircooled and watercool boys back in the heydays.

    2002 DT125R

    CalumC 1 Reply Last reply
    0
    • BluestoesonnoseB Bluestoesonnose

      LC motors are alloy and it seems to be a wide spread practice with the aircooled and watercool boys back in the heydays.

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

      @Bluestoesonnose I know LC motors are alloy, I was specifically referring to the AC motors since I'd expect this to be where it would work reliably.

      But I've not heard anyone do it to DT's. I guess there must be a reason why it's not so common these days.

      Always Originate, Never Pirate!

      1 Reply Last reply
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      • BluestoesonnoseB Offline
        BluestoesonnoseB Offline
        Bluestoesonnose
        wrote on last edited by
        #5

        Not totally clear in your reply

        2002 DT125R

        CalumC 1 Reply Last reply
        0
        • BluestoesonnoseB Bluestoesonnose

          Not totally clear in your reply

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

          @Bluestoesonnose I'm not saying it's not possible, I do question it's reliability. O-Ring modification would probably be your best bet. But the discussed factors should be considered.

          Always Originate, Never Pirate!

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          0
          • 2 Offline
            2 Offline
            2stroketerry
            wrote on last edited by
            #7

            The O-ring conversion on a DT 125 using a 90,s YZ 125 O-ring , the tighter squish and less combustion volume really helped. On average I would say this mod gives around 1,0 a 1,5 HP. This will lower the squish from +/-1.35 to a +/-0.95mm
            0_1541544295916_DT.jpg

            CalumC 1 Reply Last reply
            1
            • 2 2stroketerry

              The O-ring conversion on a DT 125 using a 90,s YZ 125 O-ring , the tighter squish and less combustion volume really helped. On average I would say this mod gives around 1,0 a 1,5 HP. This will lower the squish from +/-1.35 to a +/-0.95mm
              0_1541544295916_DT.jpg

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

              @2stroketerry That looks the tits. Who did that for you?

              Always Originate, Never Pirate!

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              • 2 Offline
                2 Offline
                2stroketerry
                wrote on last edited by
                #9

                Cost £30 to cut the groove from a machine shop in Southbank
                0_1541546069494_DT2.jpg

                declanD 1 Reply Last reply
                0
                • 2 2stroketerry

                  Cost £30 to cut the groove from a machine shop in Southbank
                  0_1541546069494_DT2.jpg

                  declanD Offline
                  declanD Offline
                  declan
                  wrote on last edited by
                  #10

                  @2stroketerry I’m surprised you lot like the o rings I hate them with a passion I love the simple metal one like dt has I’m always having leaks and such from poorly fitted o rings even though I try my best to fit them perfectly

                  CalumC 1 Reply Last reply
                  0
                  • declanD declan

                    @2stroketerry I’m surprised you lot like the o rings I hate them with a passion I love the simple metal one like dt has I’m always having leaks and such from poorly fitted o rings even though I try my best to fit them perfectly

                    CalumC Offline
                    CalumC Offline
                    Calum
                    wrote on last edited by
                    #11

                    @declan That's your problem then isn't it. Poorly fitted.

                    I've not had issues with O-Ring gaskets. Usually a dab of grease to hold it in situ is enough to sort any problems out if you're having them.

                    Always Originate, Never Pirate!

                    declanD 1 Reply Last reply
                    0
                    • CalumC Calum

                      @declan That's your problem then isn't it. Poorly fitted.

                      I've not had issues with O-Ring gaskets. Usually a dab of grease to hold it in situ is enough to sort any problems out if you're having them.

                      declanD Offline
                      declanD Offline
                      declan
                      wrote on last edited by
                      #12

                      @Calum none of that worked for me they wouldn’t sit still the last one I did I used the lightest amount of super glue just enough to keep it in the groove and that worked any other time and it would always slip out an pinch the ring I should add this is on the cheap replica rs cylinders so the machining wasn’t exactly flawless

                      1 Reply Last reply
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                      • 2 Offline
                        2 Offline
                        2stroketerry
                        wrote on last edited by
                        #13

                        @declan using glue is the last thing you want on an O-ring just a bit of silicone grease, but having a poorly machined groove the O-ring sits in probably doesn't help.
                        Yamaha use an O-ring on there best 125 cylinders the SP although don't actualy make that cylinder themselves.

                        declanD 1 Reply Last reply
                        0
                        • NINJAN Offline
                          NINJAN Offline
                          NINJA
                          wrote on last edited by NINJA
                          #14

                          I seem to remember someone once said that applying a bit of petroleum jelly, aka the good ole Vaseline works wonders for keeping your 'O' ring in good order.

                          :grinning_face_with_smiling_eyes: :winking_face: :grinning_face_with_smiling_eyes::winking_face: :grinning_face_with_smiling_eyes:

                          SEDUCED BY THE DARK SIDE!!!

                          declanD 1 Reply Last reply
                          1
                          • 2 2stroketerry

                            @declan using glue is the last thing you want on an O-ring just a bit of silicone grease, but having a poorly machined groove the O-ring sits in probably doesn't help.
                            Yamaha use an O-ring on there best 125 cylinders the SP although don't actualy make that cylinder themselves.

                            declanD Offline
                            declanD Offline
                            declan
                            wrote on last edited by
                            #15

                            @2stroketerry the only bike I didn’t have a problem with was a yz 125 that was no issues what so ever

                            1 Reply Last reply
                            0
                            • NINJAN NINJA

                              I seem to remember someone once said that applying a bit of petroleum jelly, aka the good ole Vaseline works wonders for keeping your 'O' ring in good order.

                              :grinning_face_with_smiling_eyes: :winking_face: :grinning_face_with_smiling_eyes::winking_face: :grinning_face_with_smiling_eyes:

                              declanD Offline
                              declanD Offline
                              declan
                              wrote on last edited by
                              #16

                              @NINJA you’d know

                              NINJAN 1 Reply Last reply
                              0
                              • declanD declan

                                @NINJA you’d know

                                NINJAN Offline
                                NINJAN Offline
                                NINJA
                                wrote on last edited by
                                #17

                                @declan Do not tell me that you did not laugh at that one???

                                SEDUCED BY THE DARK SIDE!!!

                                declanD 1 Reply Last reply
                                0
                                • NINJAN NINJA

                                  @declan Do not tell me that you did not laugh at that one???

                                  declanD Offline
                                  declanD Offline
                                  declan
                                  wrote on last edited by
                                  #18

                                  @NINJA sorry to say I didn’t i take my o rings very seriously I’m quite anal about o rings

                                  1 Reply Last reply
                                  1
                                  • CalumC Offline
                                    CalumC Offline
                                    Calum
                                    wrote on last edited by
                                    #19

                                    Like with most things, the work is in the preparation.

                                    Always Originate, Never Pirate!

                                    1 Reply Last reply
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