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DT125R FORUM

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  4. So Close!...

So Close!...

Scheduled Pinned Locked Moved DTR
1.1k Posts 26 Posters 208.1k Views
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  • CalumC Calum

    @SpookDog you are mental 🤣 you do serious mileage on your bike. I haven't ridden any of my motorbikes since July. Fired up the DT yesterday, took a few kicks but akk seemed well.

    S Offline
    S Offline
    SpookDog
    wrote on last edited by
    #353

    @Calum

    I know, if the weather is adverse I feel obliged to test myself against it ☠️

    I cleaned out the bowl of my carb last night before I went out, specifically the pilot jet because it’s not been starting or running great at low revs. It’s like a different animal again! Great starting, smooth revs all through the bottom to ‘top’ mid range. I’m surprised how much of the rev range is actually affected by the pilot jetting!
    When I removed the pilot and blew it through you still couldn’t see a definitively clear hole (it was opaque) I had to use a thin, kinda serated wire to clear it till it showed properly to the eye. I don’t know if it’s a hard deposit build up or a ‘gluoopy’ oil residue? But something seems to be regularily obscuring the jets bore. Maybe cause I’m running pre~mix? (Castro Racing) The filter on the fuel tap looks great, also I’ve got a good new filter in-line between the tank & carb. I don’t really understand its cause 😐 …

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    • primal carnageP Offline
      primal carnageP Offline
      primal carnage
      wrote on last edited by
      #354
      This post is deleted!
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      • S SpookDog

        @Calum

        I know, if the weather is adverse I feel obliged to test myself against it ☠️

        I cleaned out the bowl of my carb last night before I went out, specifically the pilot jet because it’s not been starting or running great at low revs. It’s like a different animal again! Great starting, smooth revs all through the bottom to ‘top’ mid range. I’m surprised how much of the rev range is actually affected by the pilot jetting!
        When I removed the pilot and blew it through you still couldn’t see a definitively clear hole (it was opaque) I had to use a thin, kinda serated wire to clear it till it showed properly to the eye. I don’t know if it’s a hard deposit build up or a ‘gluoopy’ oil residue? But something seems to be regularily obscuring the jets bore. Maybe cause I’m running pre~mix? (Castro Racing) The filter on the fuel tap looks great, also I’ve got a good new filter in-line between the tank & carb. I don’t really understand its cause 😐 …

        S Offline
        S Offline
        SpookDog
        wrote on last edited by
        #355

        @SpookDog

        Hoop! Talking to myself! 👀

        Bike chewed up a piston ring last night. Just lost power and started clattering, killed it like a heat seize with the clutch. Took the exhaust off tonight and peeked into the exhaust port. One ring down and a lot of shiny new scratches on my (previously pristine) 3MB cylinder head ☠️
        I had to nurse it 30 miles to get home to safety. So I’m guessing if any of it dropped down a transfer port I’ve lost the crank and cases as well. Oh well, shit happens…

        Can’t help thinking that there are loads more worthy candidates out there than me tho’ 😵‍💫

        CalumC 1 Reply Last reply
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        • S SpookDog

          @SpookDog

          Hoop! Talking to myself! 👀

          Bike chewed up a piston ring last night. Just lost power and started clattering, killed it like a heat seize with the clutch. Took the exhaust off tonight and peeked into the exhaust port. One ring down and a lot of shiny new scratches on my (previously pristine) 3MB cylinder head ☠️
          I had to nurse it 30 miles to get home to safety. So I’m guessing if any of it dropped down a transfer port I’ve lost the crank and cases as well. Oh well, shit happens…

          Can’t help thinking that there are loads more worthy candidates out there than me tho’ 😵‍💫

          CalumC Offline
          CalumC Offline
          Calum
          wrote on last edited by
          #356

          @SpookDog wtf! I have never seen someone have as much bad luck with these engines as you.

          All I can think is that you are caining it everywhere and you do lots of mileage. But in the 12 years of ownership of my bike I have only blown the head gasket after I used a cheap one after my bike got stolen...

          Always Originate, Never Pirate!

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          • CalumC Calum

            @SpookDog wtf! I have never seen someone have as much bad luck with these engines as you.

            All I can think is that you are caining it everywhere and you do lots of mileage. But in the 12 years of ownership of my bike I have only blown the head gasket after I used a cheap one after my bike got stolen...

            S Offline
            S Offline
            SpookDog
            wrote on last edited by
            #357

            @Calum

            It feels like bad luck for sure, but the head gasket problems were just my ignorance and previous boners putting wrong jets in the wrong carb. My head problems are totally solved now…
            I’ve never had a two stroke or any other engine have a ring let go though. I’m guessing it happens at the exhaust port where the rings have to bridge the biggest ‘void’. My barrel/piston was a bit worn and egg shaped judging by the ‘slap’ movement in the piston. So it’s my own fault. I was really hoping it would see me through till the spring tho! Oh well 💩 happens!…

            CalumC 1 Reply Last reply
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            • S SpookDog

              @Calum

              It feels like bad luck for sure, but the head gasket problems were just my ignorance and previous boners putting wrong jets in the wrong carb. My head problems are totally solved now…
              I’ve never had a two stroke or any other engine have a ring let go though. I’m guessing it happens at the exhaust port where the rings have to bridge the biggest ‘void’. My barrel/piston was a bit worn and egg shaped judging by the ‘slap’ movement in the piston. So it’s my own fault. I was really hoping it would see me through till the spring tho! Oh well 💩 happens!…

              CalumC Offline
              CalumC Offline
              Calum
              wrote on last edited by
              #358

              @SpookDog Did you make sure the Piston Ring End Gap was in tolerance upon assembly?

              In most piston kits I've had, one is within spec and the other is almost always out.

              Always Originate, Never Pirate!

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              • CalumC Calum

                @SpookDog Did you make sure the Piston Ring End Gap was in tolerance upon assembly?

                In most piston kits I've had, one is within spec and the other is almost always out.

                S Offline
                S Offline
                SpookDog
                wrote on last edited by
                #359

                @Calum

                No, I didn’t. They were new rings from pjme and they slipped in ok. I just did a quick visual with them in the barrel to make sure they weren’t doing anything extreme 🙂
                I was just hoping it’d be ok cause I rarely go above 6k and never above 7k (I still don’t know what a late 88-90 engine shoul rev to!!) Just killing time & cruising up them miles till spring 😎

                There’s no mystery, I’m just feeling sorry for me~elf 😱

                CalumC 1 Reply Last reply
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                • S SpookDog

                  @Calum

                  No, I didn’t. They were new rings from pjme and they slipped in ok. I just did a quick visual with them in the barrel to make sure they weren’t doing anything extreme 🙂
                  I was just hoping it’d be ok cause I rarely go above 6k and never above 7k (I still don’t know what a late 88-90 engine shoul rev to!!) Just killing time & cruising up them miles till spring 😎

                  There’s no mystery, I’m just feeling sorry for me~elf 😱

                  CalumC Offline
                  CalumC Offline
                  Calum
                  wrote on last edited by
                  #360

                  @SpookDog Hhmm 🤔 I wonder whether the rings were out of spec then?

                  The problem is, if they're not measured properly, the engine can heat up and expand. The rings can then butt together and then catch on an exhaust port.

                  Always Originate, Never Pirate!

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                  • CalumC Calum

                    @SpookDog Hhmm 🤔 I wonder whether the rings were out of spec then?

                    The problem is, if they're not measured properly, the engine can heat up and expand. The rings can then butt together and then catch on an exhaust port.

                    S Offline
                    S Offline
                    SpookDog
                    wrote on last edited by
                    #361

                    @Calum

                    Nah, if I hadn’t of gotten nearly 6000 trouble free miles I could agree with you. I knew the barrel was oval shaped when I first fitted it. Like I said it was a bit ‘slappy’ You could feel the excess movement in the front to back at TDC, side to side was OK. I just wasn’t expecting anything catastrophic!

                    I just find it really helpful to document my ‘happening’s’ in this thread for future reference. I used to write it down on all sorts of cardboard, pads & things but always end up misplacing it, let alone keeping date of things…
                    I need the data to work out the problems. At the moment I’d love to know if my engine RPM peaked so low normally or whether I have a miss-balanced crank that won’t let it rev to 10k+ 😵‍💫

                    CalumC 1 Reply Last reply
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                    • S SpookDog

                      @Calum

                      Nah, if I hadn’t of gotten nearly 6000 trouble free miles I could agree with you. I knew the barrel was oval shaped when I first fitted it. Like I said it was a bit ‘slappy’ You could feel the excess movement in the front to back at TDC, side to side was OK. I just wasn’t expecting anything catastrophic!

                      I just find it really helpful to document my ‘happening’s’ in this thread for future reference. I used to write it down on all sorts of cardboard, pads & things but always end up misplacing it, let alone keeping date of things…
                      I need the data to work out the problems. At the moment I’d love to know if my engine RPM peaked so low normally or whether I have a miss-balanced crank that won’t let it rev to 10k+ 😵‍💫

                      CalumC Offline
                      CalumC Offline
                      Calum
                      wrote on last edited by
                      #362

                      @SpookDog The chap who rebored my cylinder after it got stolen mentioned how oval it was 🤣

                      Always Originate, Never Pirate!

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                      • CalumC Calum

                        @SpookDog The chap who rebored my cylinder after it got stolen mentioned how oval it was 🤣

                        S Offline
                        S Offline
                        SpookDog
                        wrote on last edited by
                        #363

                        @Calum

                        Ditto my first rebore. It’s normal wear, front to back. There is no side to side pressure on a piston/barrel…

                        I have to make a list of bearings for a rebuild now. I don’t know whether to get the crank rebuilt and balanced though. I wish I could find somewhere that could check the balance…

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                        • S SpookDog

                          @Calum

                          Ditto my first rebore. It’s normal wear, front to back. There is no side to side pressure on a piston/barrel…

                          I have to make a list of bearings for a rebuild now. I don’t know whether to get the crank rebuilt and balanced though. I wish I could find somewhere that could check the balance…

                          S Offline
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                          SpookDog
                          wrote on last edited by
                          #364

                          The top ring retainer pin came loose and worked it’s way out and up (in a bounceabout kinda way 😛) into the head and through the exhaust port. So luckily both rings are still intact and never made any shrapnel down into the crank 👍. Just scratch (lol!) 1 head, barrel & piston…
                          Fitting a donor tomorrow I hope 🙂…

                          MerryXmess!…

                          CalumC 1 Reply Last reply
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                          • S SpookDog

                            The top ring retainer pin came loose and worked it’s way out and up (in a bounceabout kinda way 😛) into the head and through the exhaust port. So luckily both rings are still intact and never made any shrapnel down into the crank 👍. Just scratch (lol!) 1 head, barrel & piston…
                            Fitting a donor tomorrow I hope 🙂…

                            MerryXmess!…

                            CalumC Offline
                            CalumC Offline
                            Calum
                            wrote on last edited by
                            #365

                            @SpookDog What brand was the piston? Have you checked the piston ring end gap?

                            Always Originate, Never Pirate!

                            S 1 Reply Last reply
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                            • CalumC Calum

                              @SpookDog What brand was the piston? Have you checked the piston ring end gap?

                              S Offline
                              S Offline
                              SpookDog
                              wrote on last edited by
                              #366

                              @Calum

                              Like I said before, I didn’t measure, just a quick visual check in the barrel. It’s a jap Mitaka piston. I don’t blame the brand, it’s just a mechanical join between the aluminium piston and the brass pin that can fail in any brand piston, just bad luck 🙂 The piston had been overheated (judging by the black inside the crown) before I even brought the top end second hand. Couple that with possible vibration problems?…

                              I think the rings were RIK from PJME…

                              S 1 Reply Last reply
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                              • S SpookDog

                                @Calum

                                Like I said before, I didn’t measure, just a quick visual check in the barrel. It’s a jap Mitaka piston. I don’t blame the brand, it’s just a mechanical join between the aluminium piston and the brass pin that can fail in any brand piston, just bad luck 🙂 The piston had been overheated (judging by the black inside the crown) before I even brought the top end second hand. Couple that with possible vibration problems?…

                                I think the rings were RIK from PJME…

                                S Offline
                                S Offline
                                SpookDog
                                wrote on last edited by
                                #367

                                Day 1: 40 mile shakedown has shown no problems. Barrel & piston is a lot better condition/fit than the previous one, but by no means new. Choosy Beggars and wotnot 😎
                                Rehoned the barrel before fitting so am being gentle with the revs to let the rings settle. Nothing above 6000rpm…

                                S 1 Reply Last reply
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                                • giggscorkG Offline
                                  giggscorkG Offline
                                  giggscork
                                  wrote on last edited by
                                  #368

                                  Howdy, I'd love to answer your question but my tachometer does not function. If I fix it or get a digital guage I will let you know!

                                  S 1 Reply Last reply
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                                  • S SpookDog

                                    Day 1: 40 mile shakedown has shown no problems. Barrel & piston is a lot better condition/fit than the previous one, but by no means new. Choosy Beggars and wotnot 😎
                                    Rehoned the barrel before fitting so am being gentle with the revs to let the rings settle. Nothing above 6000rpm…

                                    S Offline
                                    S Offline
                                    SpookDog
                                    wrote on last edited by SpookDog
                                    #369
                                    This post is deleted!
                                    1 Reply Last reply
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                                    • giggscorkG giggscork

                                      Howdy, I'd love to answer your question but my tachometer does not function. If I fix it or get a digital guage I will let you know!

                                      S Offline
                                      S Offline
                                      SpookDog
                                      wrote on last edited by SpookDog
                                      #370

                                      These are the first pics of the Romeu Henrique stainless steel expansion chamber and tailpipe/serviceable muffler that I brought in Dec. I will take pics when it’s fitted to the bike…

                                      alt text

                                      alt text

                                      alt text

                                      Also below, there are the progressive fork springs. Shown next to a standard spring…

                                      alt text

                                      The 27mm hex tool (1/2 inch drive) that I got for £25 to dismantle the fork bottoms without drama! 😎 fitted to a 1/2inch extension bar (2 needed to reach inside fork)…

                                      alt text

                                      With the fork bottom inners. The inners undid with very little effort…

                                      alt text

                                      One of the fork bottom Allen bolts came out eventually. I’d already nearly rounded off the head before I removed the inner with the 27mm tool bit, so it needs replacing…

                                      The second one is still stuck in the fork bottom as you can see. The head is rounded off badly and needs heat and banging out from inside, which is now possible since removing the inner with the 27mm tool bit. It’s corroded into the fork bottom because of the dissimilar metals and the tiny gap between them…
                                      I’m waiting on a new blowtorch since my old one ha given up the ghost!…

                                      alt text

                                      I’ve gotten new bottom bolts, seals and bushes (top & bottom) to go with the springs. So the forks should be as good as new when done and powder coated…

                                      CalumC 1 Reply Last reply
                                      1
                                      • S SpookDog

                                        These are the first pics of the Romeu Henrique stainless steel expansion chamber and tailpipe/serviceable muffler that I brought in Dec. I will take pics when it’s fitted to the bike…

                                        alt text

                                        alt text

                                        alt text

                                        Also below, there are the progressive fork springs. Shown next to a standard spring…

                                        alt text

                                        The 27mm hex tool (1/2 inch drive) that I got for £25 to dismantle the fork bottoms without drama! 😎 fitted to a 1/2inch extension bar (2 needed to reach inside fork)…

                                        alt text

                                        With the fork bottom inners. The inners undid with very little effort…

                                        alt text

                                        One of the fork bottom Allen bolts came out eventually. I’d already nearly rounded off the head before I removed the inner with the 27mm tool bit, so it needs replacing…

                                        The second one is still stuck in the fork bottom as you can see. The head is rounded off badly and needs heat and banging out from inside, which is now possible since removing the inner with the 27mm tool bit. It’s corroded into the fork bottom because of the dissimilar metals and the tiny gap between them…
                                        I’m waiting on a new blowtorch since my old one ha given up the ghost!…

                                        alt text

                                        I’ve gotten new bottom bolts, seals and bushes (top & bottom) to go with the springs. So the forks should be as good as new when done and powder coated…

                                        CalumC Offline
                                        CalumC Offline
                                        Calum
                                        wrote on last edited by
                                        #371

                                        @SpookDog Pipe looks well smart!

                                        You're not linking the picture, just the Imgur post.

                                        You have to link in each picture individually.

                                        alt text

                                        alt text

                                        alt text

                                        alt text

                                        alt text

                                        alt text

                                        alt text

                                        Always Originate, Never Pirate!

                                        S 1 Reply Last reply
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                                        • CalumC Calum

                                          @SpookDog Pipe looks well smart!

                                          You're not linking the picture, just the Imgur post.

                                          You have to link in each picture individually.

                                          alt text

                                          alt text

                                          alt text

                                          alt text

                                          alt text

                                          alt text

                                          alt text

                                          S Offline
                                          S Offline
                                          SpookDog
                                          wrote on last edited by SpookDog
                                          #372

                                          @Calum

                                          Cheers bud, my mistook 😎
                                          Also in pics are the 400 x 18 & 90/90 x 21 Kenda tyres I brought for the spring. I’m running on Kenda’s at the moment and they are way better than the £100 Pirelli mt’s that I was using before…

                                          Also I wanted to say that the carbon ceramic Brembo brake pads have stood the test of time and are still performing absolutely top notch! Wet or dry they are a lot better than the EBC pads I used to run before. Well worth the £24…

                                          CalumC 1 Reply Last reply
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