Skip to content
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
Skins
  • Light
  • Brite
  • Cerulean
  • Cosmo
  • Flatly
  • Journal
  • Litera
  • Lumen
  • Lux
  • Materia
  • Minty
  • Morph
  • Pulse
  • Sandstone
  • Simplex
  • Sketchy
  • Spacelab
  • United
  • Yeti
  • Zephyr
  • Dark
  • Cyborg
  • Darkly
  • Quartz
  • Slate
  • Solar
  • Superhero
  • Vapor

  • Default (Slate)
  • No Skin
Collapse
Brand Logo

DT125R FORUM

  1. Home
  2. Tuning
  3. Top End
  4. 4FU and 32mm vs Slightly Ported Athena 170 and stock carb and 290 Jets

4FU and 32mm vs Slightly Ported Athena 170 and stock carb and 290 Jets

Scheduled Pinned Locked Moved Top End
8 Posts 3 Posters 51 Views
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • K Offline
    K Offline
    Karmona
    wrote last edited by
    #1

    Hello, my question is the following:

    4FU and 32mm vs Slightly Ported Athena 170 and stock carb and 290 Jets?

    I have a dt 125 re, im slowly restoring, and in the engine department i was thinking either one of these two options, with maybe a cdi to maximize power performnace. I will still keep the oil deposit, so that is very important, and will use it very usually. The ported cilinder is on this link if anyone wants to look at the specs:

    https://www.rrd-preparation.com/en/kit-high-engine-motorcycle-125cc-2-times/671-kit-170-cc-athena-racing-for-motor-125-derbi-gpr-yamaha-tdr-dt-tzr-2-time.html

    (Optionally we offer you an internship 1 preparation, this preparation is a slight modification of the exhaust light by increasing the diagrams. Count an extra time for this preparation!) -> This is what they offer as stage 1 prep

    Thanks!!

    1 Reply Last reply
    0
    • CalumC Offline
      CalumC Offline
      Calum
      wrote last edited by
      #2

      CDi is an absolute must if you're going modified.

      Having done most things on my DTR, I'd go ported Athena all day long. Stage 2 sounds good to me.

      The extra displacement just gives it a good punch, at the cost of overrev.

      If you're after a fast 125, ditch the DT platform and get yourself an Aprilia RX/MX/SX/RS Rotax bike.

      But if you want a faster DT, then the above is a good option.

      Get the Athena 170, Zeeltronic Ignition and a DEP pipe and you won't be disappointed.

      Bang for buck, a Rotax engine is going to be cheaper, but as I say, if you want to keep the DT, then that's a good option.

      Always Originate, Never Pirate!

      1 Reply Last reply
      1
      • K Offline
        K Offline
        Karmona
        wrote last edited by
        #3

        @calum That sounds nice, what im really after is wheelie power, and for it to be strong and for it to pull you know? Not like top end speed like 160 kmh, as this bike is clearly not built for going that fast, without spending a lot to prepare it, and it isnt really what i want it for. I want a strong, wheelie and just generel messing about machine, that has good pull and doesnt has a problem for overtaking and the likes. I dont know if that changes up things a little bit. Many many thanks for helping me out, its difficult here to get good answers locally about this bike.

        1 Reply Last reply
        0
        • CalumC Offline
          CalumC Offline
          Calum
          wrote last edited by
          #4

          Well the extra CC's definitely helps with wheelie power. The CDI gives it a much need whack up the bum. The DEP not only massively reduces the weight (especially over the front end) but increases midrange.

          The porting work is something else. Porting is almost always a compromise, you don't get something for nothing as they say.

          The 170 does benefit from a port, and I mentioned in another thread, port matching will be required anyway, and the cylinder benefits from have the spigot machine to remove the obstruction into the DTs inlet air waves.

          You do those mods, and you'll have a lovely packing machine, that's for sure!

          Always Originate, Never Pirate!

          K 2 Replies Last reply
          1
          • CalumC Calum

            Well the extra CC's definitely helps with wheelie power. The CDI gives it a much need whack up the bum. The DEP not only massively reduces the weight (especially over the front end) but increases midrange.

            The porting work is something else. Porting is almost always a compromise, you don't get something for nothing as they say.

            The 170 does benefit from a port, and I mentioned in another thread, port matching will be required anyway, and the cylinder benefits from have the spigot machine to remove the obstruction into the DTs inlet air waves.

            You do those mods, and you'll have a lovely packing machine, that's for sure!

            K Offline
            K Offline
            Karmona
            wrote last edited by
            #5

            @Calum Well then that's absolutely nice, i'll get that setup then. I asked the guys at the shop and they told me that the standard 28 carb would go well with the 290 jets, would you do that or directly upgrade to a 32? Thats the last thing i would want to know before i commit to modify the engine as you said.

            Really, many thanks for your help. Once i get everything done, i'll post the bike in its ultimate form as i'd say haha

            1 Reply Last reply
            0
            • CalumC Calum

              Well the extra CC's definitely helps with wheelie power. The CDI gives it a much need whack up the bum. The DEP not only massively reduces the weight (especially over the front end) but increases midrange.

              The porting work is something else. Porting is almost always a compromise, you don't get something for nothing as they say.

              The 170 does benefit from a port, and I mentioned in another thread, port matching will be required anyway, and the cylinder benefits from have the spigot machine to remove the obstruction into the DTs inlet air waves.

              You do those mods, and you'll have a lovely packing machine, that's for sure!

              K Offline
              K Offline
              Karmona
              wrote last edited by
              #6

              @Calum Btw, i talked to the guy Romeu Enriques, he's in portugal so there would be no problem for him to ship the pipe to me, and said he could adjust it to a port. Would you reccomend his pipe or the dep one? I initially wanted a dep one for looks mainly but if it is better i'd buy the romeu one. And many people say its better some say DEP is better, who knows really hahaha just want to know your opinion on the matter. Have a nice weekend sir

              1 Reply Last reply
              0
              • CalumC Offline
                CalumC Offline
                Calum
                wrote last edited by
                #7

                Jetting needs to be done to suit. With the upgrades you're proposing, I doubt it'll be enough for just a main jet. You'll be looking at a needle and idle jets as well.

                It is always my recommendation to jet to suit, I can't help here as I've never ran Athena on the stock carb.

                You will get benefits from a bigger carb, but the TM28 is a decent carb so you can always look to upgrade it later if you feel it's not quite working for you. For context, people tune RD350's with 28mm carbs, so I wouldn't be rushing out to replace yours on a whim.

                I use the TZR 4DL carb (Dellorto VHSA 32mm) on my ported Athena set.

                I run the Romeu Enriques pipe on my DT. It's been absolutely solid, not a spec of rust and I've had it 10+ years.

                The DEP one will rust no matter how hard you clean it. I had great success with both pipes, but I've stuck with the Romeu pipe.

                Always Originate, Never Pirate!

                1 Reply Last reply
                1
                • MadGyverM Online
                  MadGyverM Online
                  MadGyver
                  wrote last edited by MadGyver
                  #8

                  @karmona Agree with most that @Calum said.
                  Athena170 the way to go.Porting is a must,depends what you need and who will do it.
                  DEP or any other good exhaust (the thing with rust is real for DEP,5 coats of high temp black on a clean brushed DEP,and still have 2 tiny spots of rust forming)
                  TM28 is ok, if it hasn't a power jet,install one.
                  CDI you choose. Aftermarker programmable is a wise choice. OEM CDI upgrade from another Yamaha is a good compromise,depends heavily on your setup,

                  I need my tools and a pile of junk.....

                  1 Reply Last reply
                  0
                  Reply
                  • Reply as topic
                  Log in to reply
                  • Oldest to Newest
                  • Newest to Oldest
                  • Most Votes


                  • Login

                  • Don't have an account? Register

                  • Login or register to search.
                  • First post
                    Last post
                  0
                  • Recent
                  • Tags
                  • Popular
                  • Users
                  • Groups