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DT125R FORUM

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  4. Difference tzr125 and dt125

Difference tzr125 and dt125

Scheduled Pinned Locked Moved Engine
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  • Irongamer727I Irongamer727

    @calum sounds like one nice cylinder.

    CalumC Offline
    CalumC Offline
    Calum
    wrote on last edited by
    #12

    @irongamer727 Psst

    £60 buys you

    alt text
    alt text

    alt text

    Again. simply doesn't warrant the price for an okay barrel.

    Always Originate, Never Pirate!

    Irongamer727I 1 Reply Last reply
    0
    • CalumC Calum

      @irongamer727 Psst

      £60 buys you

      alt text
      alt text

      alt text

      Again. simply doesn't warrant the price for an okay barrel.

      Irongamer727I Offline
      Irongamer727I Offline
      Irongamer727
      wrote on last edited by
      #13

      @calum going a bit off topic now but what would you say makes the enduro 125's cylinder's produce so much power?

      CalumC 1 Reply Last reply
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      • Irongamer727I Irongamer727

        @calum going a bit off topic now but what would you say makes the enduro 125's cylinder's produce so much power?

        CalumC Offline
        CalumC Offline
        Calum
        wrote on last edited by
        #14

        @irongamer727 Higher compression, more aggressive port timings, bigger transfer ports, cleaner transfers, bigger boost ports. Auxilary boost ports. More spark advance. Increased squish clearance. Better designed crank journal spaced for increased fuel atomisation. Smoother inlet tracts. No emission laws to adhere to. Smaller piston to wall tolerances. Less blow by, single rings... The list goes on.

        If you're really interested then I'd recommend reading a book on a the subject as it's not something I am going to describe in a sentence or two...

        Always Originate, Never Pirate!

        Irongamer727I 1 Reply Last reply
        0
        • CalumC Calum

          @irongamer727 Higher compression, more aggressive port timings, bigger transfer ports, cleaner transfers, bigger boost ports. Auxilary boost ports. More spark advance. Increased squish clearance. Better designed crank journal spaced for increased fuel atomisation. Smoother inlet tracts. No emission laws to adhere to. Smaller piston to wall tolerances. Less blow by, single rings... The list goes on.

          If you're really interested then I'd recommend reading a book on a the subject as it's not something I am going to describe in a sentence or two...

          Irongamer727I Offline
          Irongamer727I Offline
          Irongamer727
          wrote on last edited by
          #15

          @calum jeez.

          CalumC 1 Reply Last reply
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          • Irongamer727I Irongamer727

            @calum jeez.

            CalumC Offline
            CalumC Offline
            Calum
            wrote on last edited by Calum
            #16

            @irongamer727 I'd recommend Tuning For Speed By Phil Irving PDF available online

            http://tuningforspeed.com/files/Tuning_for_Speed.pdf

            As a start

            Then have a read of Graham Bell's Two Stroke Performance Tuning
            Then Graham Bells Engine Performance Tuning

            You always want to read in Chronological order. Phil's book was written several decades ago, Grahams during the late 80's.

            Irvin was way ahead of the curve and received the highest engineering award they have in Australia. Named after him called the Irving award. The guy is a genius.

            Always Originate, Never Pirate!

            Irongamer727I 1 Reply Last reply
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            • CalumC Calum

              @irongamer727 I'd recommend Tuning For Speed By Phil Irving PDF available online

              http://tuningforspeed.com/files/Tuning_for_Speed.pdf

              As a start

              Then have a read of Graham Bell's Two Stroke Performance Tuning
              Then Graham Bells Engine Performance Tuning

              You always want to read in Chronological order. Phil's book was written several decades ago, Grahams during the late 80's.

              Irvin was way ahead of the curve and received the highest engineering award they have in Australia. Named after him called the Irving award. The guy is a genius.

              Irongamer727I Offline
              Irongamer727I Offline
              Irongamer727
              wrote on last edited by
              #17

              @calum I have Graham 2 stroke at home. First time I read it I didn't understand much. Perhaps time to do it again.

              CalumC 1 Reply Last reply
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              • Irongamer727I Irongamer727

                @calum I have Graham 2 stroke at home. First time I read it I didn't understand much. Perhaps time to do it again.

                CalumC Offline
                CalumC Offline
                Calum
                wrote on last edited by
                #18

                @irongamer727 I refer you to my previous statement.

                Start in chronological order. Ready Phil Irvins book first. As this will introduce to the concepts at the time, which are assumed or taken for granted in later books.

                Always Originate, Never Pirate!

                declanD 1 Reply Last reply
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                • CalumC Calum

                  @irongamer727 I refer you to my previous statement.

                  Start in chronological order. Ready Phil Irvins book first. As this will introduce to the concepts at the time, which are assumed or taken for granted in later books.

                  declanD Offline
                  declanD Offline
                  declan
                  wrote on last edited by
                  #19

                  @calum can you not just re sleeve a barrel like a blank slate and the copy what ever port you wish as long as the barrel it’s self allows

                  CalumC 1 Reply Last reply
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                  • declanD declan

                    @calum can you not just re sleeve a barrel like a blank slate and the copy what ever port you wish as long as the barrel it’s self allows

                    CalumC Offline
                    CalumC Offline
                    Calum
                    wrote on last edited by
                    #20

                    @declan The barrels are cast with only so much metal in them. It's not a case of inside liner. The walls are only so thick and can only be ported so much.

                    You could spend thousands and thousands porting the barrel, and the result is ultimately worse than a £60 RS barrel. It's cost vs Reward.

                    If I was going to spend X amount of money for maximum bang for buck, do an engine swap. It'll be cheaper and better.

                    So I'd rather swap the DTR engine out for a 2RK engine out of the UK spec TZR. Or better still Rotax 122 engine, or a YZ engine or anything else.

                    By all means, mildly port and tune the DTR engine, but accept that there are limitations. Ensure that what you spend, is less than what it would have to have simply swapped the engine.

                    That accounts for time as well as money. An engine may cost less than a decent port, but if it takes a year to fit then it's cost you time.

                    Always Originate, Never Pirate!

                    declanD 1 Reply Last reply
                    0
                    • CalumC Calum

                      @declan The barrels are cast with only so much metal in them. It's not a case of inside liner. The walls are only so thick and can only be ported so much.

                      You could spend thousands and thousands porting the barrel, and the result is ultimately worse than a £60 RS barrel. It's cost vs Reward.

                      If I was going to spend X amount of money for maximum bang for buck, do an engine swap. It'll be cheaper and better.

                      So I'd rather swap the DTR engine out for a 2RK engine out of the UK spec TZR. Or better still Rotax 122 engine, or a YZ engine or anything else.

                      By all means, mildly port and tune the DTR engine, but accept that there are limitations. Ensure that what you spend, is less than what it would have to have simply swapped the engine.

                      That accounts for time as well as money. An engine may cost less than a decent port, but if it takes a year to fit then it's cost you time.

                      declanD Offline
                      declanD Offline
                      declan
                      wrote on last edited by
                      #21

                      @calum gotta be a yz engine

                      CalumC 1 Reply Last reply
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                      • declanD declan

                        @calum gotta be a yz engine

                        CalumC Offline
                        CalumC Offline
                        Calum
                        wrote on last edited by
                        #22

                        @declan Not great road bikes though mate.

                        Always Originate, Never Pirate!

                        declanD 1 Reply Last reply
                        0
                        • CalumC Calum

                          @declan Not great road bikes though mate.

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

                          @calum yeah but I mean what two stroke is in the first place compared to a 4 stroke ofc

                          CalumC 1 Reply Last reply
                          0
                          • declanD declan

                            @calum yeah but I mean what two stroke is in the first place compared to a 4 stroke ofc

                            CalumC Offline
                            CalumC Offline
                            Calum
                            wrote on last edited by
                            #24

                            @declan All of them? Much higher power to weight ratio.

                            Even a 4T MX bike is not great on the road, albeit better than a 2T MX but it's still not ideal. Way too much compression and spark advance.

                            Always Originate, Never Pirate!

                            declanD 1 Reply Last reply
                            0
                            • CalumC Calum

                              @declan All of them? Much higher power to weight ratio.

                              Even a 4T MX bike is not great on the road, albeit better than a 2T MX but it's still not ideal. Way too much compression and spark advance.

                              declanD Offline
                              declanD Offline
                              declan
                              wrote on last edited by
                              #25

                              @calum I’m talking more practical here a 4 stroke almost always wins if you have deep pockets anyway all’s I’m saying is 2 strokes aren’t really at there best when they’re practical road bikes they’re supposed to be aggressive and crazy imo

                              Glynn123G 1 Reply Last reply
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                              • declanD declan

                                @calum I’m talking more practical here a 4 stroke almost always wins if you have deep pockets anyway all’s I’m saying is 2 strokes aren’t really at there best when they’re practical road bikes they’re supposed to be aggressive and crazy imo

                                Glynn123G Offline
                                Glynn123G Offline
                                Glynn123
                                wrote on last edited by
                                #26

                                DT is a pretty brilliant road bike standard

                                1 Reply Last reply
                                0
                                • O Offline
                                  O Offline
                                  oldman
                                  wrote on last edited by
                                  #27

                                  IMHO accept the Dt for what it is rather than spend lots of dollar trying to make it what it isn't. If it doesn't float your boat buy what will, I have a big bike (still) but get the same if not more enjoyment out of a small lightweight bike.

                                  CalumC 1 Reply Last reply
                                  1
                                  • Glynn123G Offline
                                    Glynn123G Offline
                                    Glynn123
                                    wrote on last edited by
                                    #28

                                    The DT is still pleanty fast for what it is, a road going bike developed for teens on L plates, it's a damn site quicker than any of the 4t 125 bikes around, and they get incredible reliability when right. I plan on doing a lot of miles with long runs this year, so simply a road going mx would not work.

                                    1 Reply Last reply
                                    0
                                    • O oldman

                                      IMHO accept the Dt for what it is rather than spend lots of dollar trying to make it what it isn't. If it doesn't float your boat buy what will, I have a big bike (still) but get the same if not more enjoyment out of a small lightweight bike.

                                      CalumC Offline
                                      CalumC Offline
                                      Calum
                                      wrote on last edited by
                                      #29

                                      @oldman I mean you're right, however, when push came to shove, I couldn't afford a bigger bike so it was easier to just chip away at tuning the DT.

                                      You 100%, but sometimes a bigger bike isn't always an option. Having done my test several years ago, I have never owned another bike. The Aprilia that I am building is the only bike I've bought since doing my bike license, and I could have had that on L plates lol.

                                      I think it's come to a point now where I could go out and buy an R1 or something, but then I know it wouldn't satisfy me.

                                      Always Originate, Never Pirate!

                                      declanD 1 Reply Last reply
                                      0
                                      • CalumC Calum

                                        @oldman I mean you're right, however, when push came to shove, I couldn't afford a bigger bike so it was easier to just chip away at tuning the DT.

                                        You 100%, but sometimes a bigger bike isn't always an option. Having done my test several years ago, I have never owned another bike. The Aprilia that I am building is the only bike I've bought since doing my bike license, and I could have had that on L plates lol.

                                        I think it's come to a point now where I could go out and buy an R1 or something, but then I know it wouldn't satisfy me.

                                        declanD Offline
                                        declanD Offline
                                        declan
                                        wrote on last edited by
                                        #30

                                        @calum cr 500 it is then😉

                                        1 Reply Last reply
                                        1
                                        • O Offline
                                          O Offline
                                          oldman
                                          wrote on last edited by
                                          #31

                                          Like many people my age have done the big bike thing up to several zx9r's and an rf 900. They were unbelievably fast but the current crop of litre bikes makes them look like mopeds in comparison. They were beyond my ability in all honesty and the temptation to use the power was always there. I was lucky never to come a cropper on one of them and the 650 I have now is more than adequate and would be my first choice for a continental tour (I wish). For a few hours out in the countryside down a few lanes content on the 125s and not as demanding mentally either as a big bike. The temptations not there to wind on the throttle or chase someone that passes. Happy to add a bit of "pep" to the 125s but no more than that, but it's a personal decision and each person's passion is different. Just find it hard to justify spending hundreds of pounds chasing a few bhp when alternative bikes are about to give that extra kick. Does not mean I will never try it though, change is good! Bike I regret selling the most is a zx9r b4 in green with a stage 1 tune (if I remember correctly), absolutely brutal and mint condition, upgraded to newer model but not the same terror when riding😊

                                          CalumC 1 Reply Last reply
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