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DT125R FORUM

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  2. Tuning
  3. Reed valves

Reed valves

Scheduled Pinned Locked Moved Tuning
14 Posts 7 Posters 6.1k Views 2 Watching
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  • A Offline
    A Offline
    andrewj1680
    wrote on last edited by
    #4

    Funny you say that calum mine is drinking fuel lately I always use super unleaded from tesco but i seem to always be filling up

    MightymanM 1 Reply Last reply
    1
    • A andrewj1680

      Funny you say that calum mine is drinking fuel lately I always use super unleaded from tesco but i seem to always be filling up

      MightymanM Offline
      MightymanM Offline
      Mightyman
      wrote on last edited by
      #5

      @Calum @andrewj1680 definitely worth giving them a check then by the sounds of it! 👍

      TDR 125 - 2001

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

        So just to clarify:

        Reed Valve /Torque Induction

        The reed valve, formerly known as Torque Induction was a system developed by Yamaha to solve the problem of spitting unburnt fuel back into the carburetor.

        Previously the carburetor sat as the inlet, air/fuel was sucked through the vacuum created by the piston upon induction. However during compression the fuel was able to flow back into the carburetor.

        Kawasaki answered this problem with the rotary discs, but it wasn't until Yamaha developed the reed valve did the problem of keeping it simple was solved.

        Effectively, as the name suggests, the reed valve operators in a similar fashion as to how they would on a wood instrument, effectively air can pass through the reeds as the force exerted on them causes the reed to lift, however the back pressure won't cause the reed to open.

        You effectively create a really simple one way system.

        If the reeds are bent then fuel and air can come and go on compression and induction. So fuel is going to be spat back into the carburetor. Power is going to be down as fuel atomisation is effected due to the turbulence created.

        As the power of an engine increases, so must the rigity of the reeds. At high power/rpms you can cause an effect known as Reed Flutter. What happens here is that the force exerted on the reeds as induction occurs causes the reeds to bounce on the cage, when the RPM's are high, the bounce could carry over to the compression phase, cause fuel/air to be forced back into the inlet track.

        Stiffer carbon reeds are less prone to reed flutter, hence why they are considered an upgrade. However YZ125's come with the same plastic reeds as the DT as standard. If it's good enough for 33bhp+ it's good enough for 15. But an upgrade is an upgrade never the less. It is probably cheaper to get carbon ones than OEM plastic ones.

        Hopefully that clears any misinformation up.

        Always Originate, Never Pirate!

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        • DartyD Offline
          DartyD Offline
          Darty
          wrote on last edited by
          #7

          http://www.catalyst-findit.co.uk/index.php?c=d2f5d910014f2842ada1bbc16c273aae&vat=ex&dest=prod&p=257&pid=05-666&PHPSESSID=88vc9khh91hjb4m1847c2hfsg0

          Boyesen are quality.

          Keep it real

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          • B Offline
            B Offline
            Bentley
            wrote on last edited by
            #8

            @Darty @Calum would the boyseen reeds be any better than the carbon ones off eBay? I was going to ask this question but found this thread. They claim to have an effect on performance but the carbon reeds on eBay don't 🤔 I personally imagine they are the same anyone know?

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            • CalumC Offline
              CalumC Offline
              Calum
              wrote on last edited by
              #9

              I run these

              http://www.ebay.co.uk/itm/Yamaha-DTR125-DT-125-R-HYTECH-Racing-Reeds-HT15-/181931302789

              Everybody loves a bit of CF.

              I don't get the point in the Boyseen if they are just plastic, how are they better than OEM. At least the carbon ones are carbon

              Always Originate, Never Pirate!

              DartyD 1 Reply Last reply
              0
              • CalumC Calum

                I run these

                http://www.ebay.co.uk/itm/Yamaha-DTR125-DT-125-R-HYTECH-Racing-Reeds-HT15-/181931302789

                Everybody loves a bit of CF.

                I don't get the point in the Boyseen if they are just plastic, how are they better than OEM. At least the carbon ones are carbon

                DartyD Offline
                DartyD Offline
                Darty
                wrote on last edited by
                #10

                @Calum

                I quote...

                : Please Note: Only CF part numbers are carbon fibre (HT part numbers are not carbon fibre) ?? These are not even Dry carbon?

                I have to add, that Carbon reeds are very stiff, it's actually less than ideal for the DT.

                Stick to plastic I say, Boyesen follow production specs, which are ideal to start with.

                Keep it real

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

                  Looked like carbon to me

                  alt

                  Always Originate, Never Pirate!

                  1 Reply Last reply
                  1
                  • DartyD Offline
                    DartyD Offline
                    Darty
                    wrote on last edited by
                    #12

                    They look sick, trouble with Carbon fibre is it does not flex fluidly and fractures like a bitch..

                    I am dubious of having one rip itself apart into the crankcase,

                    I've got a CR125 MotoTassinari VFORCE 3 Reed block to try on the DT,

                    Will post results, should clean up the Mid-range RPMs a little bit.

                    Keep it real

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

                      This dude on ebay sells carbon reeds for all DT's;

                      http://www.ebay.co.uk/itm/CHAO-Carbon-Fiber-Reeds-for-Yamaha-DT-125-R-Stage1-/391528354319?hash=item5b28e8920f:g:07IAAOSwPhdU7cqu

                      He also does a stage 2 kit as well, but doesn't have any listed ATM sadly!!! 😞

                      SEDUCED BY THE DARK SIDE!!!

                      1 Reply Last reply
                      0
                      • Louis-DT-WRL Offline
                        Louis-DT-WRL Offline
                        Louis-DT-WR
                        wrote on last edited by
                        #14

                        No very noticeable, although my v-force v3 works very well, especially in the high revs 🙂 see my 200cc conversion thread

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