Skip to content
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
Skins
  • Light
  • 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. Technical Zone
  3. Engine
  4. Runs with choke

Runs with choke

Scheduled Pinned Locked Moved Engine
76 Posts 6 Posters 7.9k 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.
  • OllieDTRO OllieDTR

    @SpookDog

    A socket mate on the edge of the seal but must of not put it in even, I’ve got my old seal now and a tube that slots over so should be smooth sailing..
    will update you tomorrow 😊

    S Offline
    S Offline
    SpookDog
    wrote on last edited by SpookDog
    #25

    @OllieDTR

    I forgot to ask! Did you check your clutch side seal for similar damage? Might as well do it while the doings good, no?…
    I did most damage to that side on mine! 🥴

    OllieDTRO 1 Reply Last reply
    0
    • S SpookDog

      @OllieDTR

      I forgot to ask! Did you check your clutch side seal for similar damage? Might as well do it while the doings good, no?…
      I did most damage to that side on mine! 🥴

      OllieDTRO Offline
      OllieDTRO Offline
      OllieDTR
      wrote on last edited by
      #26

      @SpookDog

      Seals arrived today! Didn’t get time to put it in as finished work late and wanted a fresh head on it.
      Yes I’m going to do both sides, I’ve removed both seals the other day by drilling a small hole in them and then use a screw couple turns and then pull it out.
      I’ve got with high quality viton seals this time as fuel and high heat resistant 😁

      Finally can put the bike back together tomorrow! Being the electric start engine that’s 2004+? Correct?

      So carburettor settings is and correct me if I’m wrong
      240 main
      25 pilot
      4th clip

      Oh I’ve also ordered a snorkel for the airbox as previous owner decided to remove it but I’ve always found they run better with them in.

      alt text

      S 1 Reply Last reply
      0
      • OllieDTRO OllieDTR

        @SpookDog

        Seals arrived today! Didn’t get time to put it in as finished work late and wanted a fresh head on it.
        Yes I’m going to do both sides, I’ve removed both seals the other day by drilling a small hole in them and then use a screw couple turns and then pull it out.
        I’ve got with high quality viton seals this time as fuel and high heat resistant 😁

        Finally can put the bike back together tomorrow! Being the electric start engine that’s 2004+? Correct?

        So carburettor settings is and correct me if I’m wrong
        240 main
        25 pilot
        4th clip

        Oh I’ve also ordered a snorkel for the airbox as previous owner decided to remove it but I’ve always found they run better with them in.

        alt text

        S Offline
        S Offline
        SpookDog
        wrote on last edited by
        #27

        @OllieDTR

        Looks good! Yep the needle should be 2nd groove up from the bottom (4 from top) So it could only go one groove higher if wanted…

        It’ll run like a dream after this bud! 👍 …

        1 Reply Last reply
        0
        • OllieDTRO Offline
          OllieDTRO Offline
          OllieDTR
          wrote on last edited by
          #28

          Update:

          Changed crank seals, no change, so I thought I’d check everything again, cleaned all jets, checked float height and it was 16mm, so I did some research and the float heigh is 20 - 21mm it says in the Haynes anybody got there’s at that?
          Alittle better but not full fixed, so I thought fresh fuel Abit better again can get it to bog on rev now but will rev past,

          Thing I’ve ruled it down to now is air…
          Previous owner cut the airbox, so I’ve ordered a snorkel and what I’m going to do is stick a plastic cover back onto the top of the air box and then cut out a slot with a dremel so the snorkel fits so it’s back to oem, as when you rev it you can hear the mass amount of air being rushed in.

          I still don’t know why people remove the snorkel and cut the airbox.. Yamaha has probably done so much testing and that is what is best for the flow and feed of air. So I’m 100% certain it’s that as makes sense now runs on choke so that means it’s getting more fuel and when you’ve got more air you’ll need more fuel so choke is the answer.

          If someone can please let me know on the float height if I’m wrong above thank you !

          Hopefully it’s here before weekend and then I’ll be back to update you all 😅

          HOTSHOT IIIH 1 Reply Last reply
          0
          • OllieDTRO OllieDTR

            Update:

            Changed crank seals, no change, so I thought I’d check everything again, cleaned all jets, checked float height and it was 16mm, so I did some research and the float heigh is 20 - 21mm it says in the Haynes anybody got there’s at that?
            Alittle better but not full fixed, so I thought fresh fuel Abit better again can get it to bog on rev now but will rev past,

            Thing I’ve ruled it down to now is air…
            Previous owner cut the airbox, so I’ve ordered a snorkel and what I’m going to do is stick a plastic cover back onto the top of the air box and then cut out a slot with a dremel so the snorkel fits so it’s back to oem, as when you rev it you can hear the mass amount of air being rushed in.

            I still don’t know why people remove the snorkel and cut the airbox.. Yamaha has probably done so much testing and that is what is best for the flow and feed of air. So I’m 100% certain it’s that as makes sense now runs on choke so that means it’s getting more fuel and when you’ve got more air you’ll need more fuel so choke is the answer.

            If someone can please let me know on the float height if I’m wrong above thank you !

            Hopefully it’s here before weekend and then I’ll be back to update you all 😅

            HOTSHOT IIIH Offline
            HOTSHOT IIIH Offline
            HOTSHOT III
            wrote on last edited by
            #29

            @OllieDTR I've always set the float heights on all my TM28SS carbs to 16mm and never had an issue ('93 3NC, '98 3MB and my '98 3NC on which the carb had been so butchered with silicone sealant down the vent holes etc. I ended up just replacing it with one good carb made of two spares). I read in the TZR125R Yamaha service manual that it's 15.5-16.5mm for that bike where the TM28SS is fitted (UK, France etc.) and I didn't have any other Yamaha service info at the time and so just went with it. The moulding line around the plastic parts of the floats is about parallel with the float bowl gasket face at 16mm and that is usually a good indicator that the float height is about right on most Japanese bike carbs.

            I'm afraid Haynes never quite got their head around the fact the '88 DTR has a VM26SS carb (same as the original TZR125) and then changed over to the TM28SS flat slide in '89 after one year of production. So various editions of the Haynes manual for the DTR have some pretty big mistakes in the carb section; I think where they specify 20-21mm float height for the TM28SS they got mixed up with the VM26SS, and they list VM26 jet sizes for the TM28 in some parts of the manual, and in others they just say all DTRs have a VM26!

            It sounds to me like the previous owner has cut a big hole in the top of the airbox "because YZ125" and this is probably what is causing the lean running condition as you say. It's certainly not helping so fixing this and refitting the snorkel before trying anything else is the right approach IMO 👍

            OllieDTRO 1 Reply Last reply
            0
            • HOTSHOT IIIH HOTSHOT III

              @OllieDTR I've always set the float heights on all my TM28SS carbs to 16mm and never had an issue ('93 3NC, '98 3MB and my '98 3NC on which the carb had been so butchered with silicone sealant down the vent holes etc. I ended up just replacing it with one good carb made of two spares). I read in the TZR125R Yamaha service manual that it's 15.5-16.5mm for that bike where the TM28SS is fitted (UK, France etc.) and I didn't have any other Yamaha service info at the time and so just went with it. The moulding line around the plastic parts of the floats is about parallel with the float bowl gasket face at 16mm and that is usually a good indicator that the float height is about right on most Japanese bike carbs.

              I'm afraid Haynes never quite got their head around the fact the '88 DTR has a VM26SS carb (same as the original TZR125) and then changed over to the TM28SS flat slide in '89 after one year of production. So various editions of the Haynes manual for the DTR have some pretty big mistakes in the carb section; I think where they specify 20-21mm float height for the TM28SS they got mixed up with the VM26SS, and they list VM26 jet sizes for the TM28 in some parts of the manual, and in others they just say all DTRs have a VM26!

              It sounds to me like the previous owner has cut a big hole in the top of the airbox "because YZ125" and this is probably what is causing the lean running condition as you say. It's certainly not helping so fixing this and refitting the snorkel before trying anything else is the right approach IMO 👍

              OllieDTRO Offline
              OllieDTRO Offline
              OllieDTR
              wrote on last edited by
              #30

              @HOTSHOT-III

              I can always change float height back to 16mm not an issue, I’ve got the snorkel hopefully coming tomorrow so I can patch the airbox up and have the correct amount of air coming in as it should be so can work from there as it’s all guess work without 👍🏻

              S 2 Replies Last reply
              1
              • OllieDTRO OllieDTR

                @HOTSHOT-III

                I can always change float height back to 16mm not an issue, I’ve got the snorkel hopefully coming tomorrow so I can patch the airbox up and have the correct amount of air coming in as it should be so can work from there as it’s all guess work without 👍🏻

                S Offline
                S Offline
                SpookDog
                wrote on last edited by SpookDog
                #31

                @OllieDTR

                Off the top of my head it does say 21mm in the Haynes manual, but like @HOTSHOT-III says, they make fux ups all over the place with carbs and wiring diagrams just being ones I’ve had ‘problems’ with 🙂 …

                21 sounds like such a big leap for a carb with the same bowl as the other iterations. But, like you said, you can always change it back. I’d try anything if I was in your shoes bud…

                1 Reply Last reply
                1
                • OllieDTRO OllieDTR

                  @HOTSHOT-III

                  I can always change float height back to 16mm not an issue, I’ve got the snorkel hopefully coming tomorrow so I can patch the airbox up and have the correct amount of air coming in as it should be so can work from there as it’s all guess work without 👍🏻

                  S Offline
                  S Offline
                  SpookDog
                  wrote on last edited by SpookDog
                  #32

                  @OllieDTR

                  Have you checked the gasket on the carbs slide body? Or the slide top? Anywhere that unmetered air can be getting in? Cracks in the rubber mount even? I personally can’t see the air box being the problem, but it’s a good idea to put every variable back to standard…

                  If it helps I’d be up to lending you my spare carb to see if swapping it out makes any difference. The jets I have for it are richer, I accidentally opened up the .25 pilot and I only have an aftermarket 250 main for it, but it works…
                  It’s in Poole…

                  PS have you got the little tube connecting the power jet from the throttle body to the bowl? If that wasn’t connected it could suck air in there…

                  OllieDTRO 1 Reply Last reply
                  1
                  • CalumC Offline
                    CalumC Offline
                    Calum
                    wrote on last edited by
                    #33

                    The airbox on the DTR is pretty restrictive to be fair. Was a common modification by a lot of people tuning their DTRs to cut the entire top section of the airbox off, when these bikes were a dime a dozen.

                    I purely ran a pod filter on my DTR and am very happy with how it performs. Cutting the box these days seems sacralige but that's just how it was back then.

                    Either way, when you're diagnosing faults it's always good to go to known working.

                    Always Originate, Never Pirate!

                    S 1 Reply Last reply
                    1
                    • CalumC Calum

                      The airbox on the DTR is pretty restrictive to be fair. Was a common modification by a lot of people tuning their DTRs to cut the entire top section of the airbox off, when these bikes were a dime a dozen.

                      I purely ran a pod filter on my DTR and am very happy with how it performs. Cutting the box these days seems sacralige but that's just how it was back then.

                      Either way, when you're diagnosing faults it's always good to go to known working.

                      S Offline
                      S Offline
                      SpookDog
                      wrote on last edited by SpookDog
                      #34

                      @Calum

                      The only thing that the pod filter would affect would be the power jet…

                      Ram Air used to make a kit for the Z1000’s (back at the end of the last century!) they used to supply a drill tap and ‘recalibrated’ screw-in brass jet because it looses some of the ‘suction’ caused by the standard long air intake. Interesting stuff!…

                      OllieDTRO 1 Reply Last reply
                      0
                      • S SpookDog

                        @OllieDTR

                        Have you checked the gasket on the carbs slide body? Or the slide top? Anywhere that unmetered air can be getting in? Cracks in the rubber mount even? I personally can’t see the air box being the problem, but it’s a good idea to put every variable back to standard…

                        If it helps I’d be up to lending you my spare carb to see if swapping it out makes any difference. The jets I have for it are richer, I accidentally opened up the .25 pilot and I only have an aftermarket 250 main for it, but it works…
                        It’s in Poole…

                        PS have you got the little tube connecting the power jet from the throttle body to the bowl? If that wasn’t connected it could suck air in there…

                        OllieDTRO Offline
                        OllieDTRO Offline
                        OllieDTR
                        wrote on last edited by
                        #35

                        @SpookDog

                        A different carb sounds like my next step mate after the snorkel as I can’t think where it could be coming in now, everything is sealed with new gaskets so if it’s not the snorkel it’s the carb,

                        I’m in Weymouth Dorset so only down the road, I might have to take you up on the offer of borrowing it mate to see what it idles like if that’s the case I’ll be purchasing one soon as I know
                        Thank you

                        1 Reply Last reply
                        0
                        • S SpookDog

                          @Calum

                          The only thing that the pod filter would affect would be the power jet…

                          Ram Air used to make a kit for the Z1000’s (back at the end of the last century!) they used to supply a drill tap and ‘recalibrated’ screw-in brass jet because it looses some of the ‘suction’ caused by the standard long air intake. Interesting stuff!…

                          OllieDTRO Offline
                          OllieDTRO Offline
                          OllieDTR
                          wrote on last edited by
                          #36

                          @SpookDog

                          The only other thing I can think of air getting in is…

                          So the reed rubber bit where it goes onto the reed valve that has its own gasket doesn’t it the rubber bit, I’ve put a gasket onto that as it’s got a reed spaced air wouldn’t get in there would it? Or would it be best to take that gasket out and just put it without as it is from factory?

                          Thanks

                          S 1 Reply Last reply
                          0
                          • MadGyverM Offline
                            MadGyverM Offline
                            MadGyver
                            wrote on last edited by
                            #37

                            Is the rubber joint for the carb ok, maybe has a crack and with the vibrations from a running engine sucks air or it's become too stiff and doesn't seals properly with the carb.

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

                            1 Reply Last reply
                            1
                            • OllieDTRO OllieDTR

                              @SpookDog

                              The only other thing I can think of air getting in is…

                              So the reed rubber bit where it goes onto the reed valve that has its own gasket doesn’t it the rubber bit, I’ve put a gasket onto that as it’s got a reed spaced air wouldn’t get in there would it? Or would it be best to take that gasket out and just put it without as it is from factory?

                              Thanks

                              S Offline
                              S Offline
                              SpookDog
                              wrote on last edited by SpookDog
                              #38

                              @OllieDTR

                              There’s a gasket below the metal reed valve. None above (and between) the reed valve and rubber intake (it has its own seal). If you’ve fitted one strip it down and try again. The inlet is the most likely cause for your symptoms…

                              Do you have much hands on experience with engines, or is this a first bike?
                              One of my first experiences with the dtr was an almost Invisible split in the rubber mount…

                              S 1 Reply Last reply
                              0
                              • S SpookDog

                                @OllieDTR

                                There’s a gasket below the metal reed valve. None above (and between) the reed valve and rubber intake (it has its own seal). If you’ve fitted one strip it down and try again. The inlet is the most likely cause for your symptoms…

                                Do you have much hands on experience with engines, or is this a first bike?
                                One of my first experiences with the dtr was an almost Invisible split in the rubber mount…

                                S Offline
                                S Offline
                                SpookDog
                                wrote on last edited by
                                #39

                                Have you changed the jetting, or is it the same as in the start of the thread?
                                210
                                .225
                                Ect?

                                OllieDTRO 1 Reply Last reply
                                0
                                • S SpookDog

                                  Have you changed the jetting, or is it the same as in the start of the thread?
                                  210
                                  .225
                                  Ect?

                                  OllieDTRO Offline
                                  OllieDTRO Offline
                                  OllieDTR
                                  wrote on last edited by
                                  #40

                                  @SpookDog

                                  I’ll take the gasket off today mate, I’ve had a couple dts and mx bike I’ve always done rebuilds on but this one seems to be testing me…

                                  I’m currently running 240 main
                                  25 pilot

                                  Went for a ride on choke then turn choke off when moving goes for Abit then bogs when let off and try to use throttle again just bogs but flick the choke back up and runs again

                                  Am I thinking it’s lean?

                                  I’m off to get some brake cleaner in a minute and going to test for leaks again

                                  S 1 Reply Last reply
                                  0
                                  • OllieDTRO OllieDTR

                                    @SpookDog

                                    I’ll take the gasket off today mate, I’ve had a couple dts and mx bike I’ve always done rebuilds on but this one seems to be testing me…

                                    I’m currently running 240 main
                                    25 pilot

                                    Went for a ride on choke then turn choke off when moving goes for Abit then bogs when let off and try to use throttle again just bogs but flick the choke back up and runs again

                                    Am I thinking it’s lean?

                                    I’m off to get some brake cleaner in a minute and going to test for leaks again

                                    S Offline
                                    S Offline
                                    SpookDog
                                    wrote on last edited by SpookDog
                                    #41

                                    @OllieDTR

                                    It’s definitely lean. It’s just where the fux it’s taking unmetered air at? The power jet pipe is connected, yeah?

                                    OllieDTRO 1 Reply Last reply
                                    0
                                    • S SpookDog

                                      @OllieDTR

                                      It’s definitely lean. It’s just where the fux it’s taking unmetered air at? The power jet pipe is connected, yeah?

                                      OllieDTRO Offline
                                      OllieDTRO Offline
                                      OllieDTR
                                      wrote on last edited by
                                      #42

                                      @SpookDog

                                      Powerjet is connected, I’ve blasted brake cleaner around everywhere and no change in revs, I’m going to completely take the carb apart everything and clean and check everything

                                      S 1 Reply Last reply
                                      0
                                      • OllieDTRO OllieDTR

                                        @SpookDog

                                        Powerjet is connected, I’ve blasted brake cleaner around everywhere and no change in revs, I’m going to completely take the carb apart everything and clean and check everything

                                        S Offline
                                        S Offline
                                        SpookDog
                                        wrote on last edited by
                                        #43

                                        @OllieDTR

                                        I had to ask, I honestly don’t think that you’re as big an idiot as me 🙂 I just don’t understand where an air leak big enough that changing the jetting as you have, has made no difference, can be…

                                        Again, sorry, I have to ask! You are spraying and checking while the choke is off? When I sprayed even a tiny bit near where the leak was my engine stopped ‘hunting’ and settled down.
                                        Yours will tick over without choke yes? But be all ‘fast & twangy’?

                                        There are only so many places air can enter unmetered

                                        OllieDTRO 1 Reply Last reply
                                        0
                                        • S SpookDog

                                          @OllieDTR

                                          I had to ask, I honestly don’t think that you’re as big an idiot as me 🙂 I just don’t understand where an air leak big enough that changing the jetting as you have, has made no difference, can be…

                                          Again, sorry, I have to ask! You are spraying and checking while the choke is off? When I sprayed even a tiny bit near where the leak was my engine stopped ‘hunting’ and settled down.
                                          Yours will tick over without choke yes? But be all ‘fast & twangy’?

                                          There are only so many places air can enter unmetered

                                          OllieDTRO Offline
                                          OllieDTRO Offline
                                          OllieDTR
                                          wrote on last edited by
                                          #44

                                          @SpookDog

                                          Fixed it!!!

                                          So airscrew didn’t have a o ring so put one in.
                                          Also when I was checking air leaks nothing, so I thought I’d take carb out and check all rubbers, where the jubliee clip tightens up onto the carb on inlet there was a hairline crack under the clip which I only saw when I flexed it about. so put the carb back on and sprayed like 2mm away from the place I saw the crack and sure thing revved up. So that’s why I didn’t rev before when I sprayed because I had to be really really close to it!

                                          After all that 😅 I’m glad though crazy how a tiny tiny little crack can do that but where it was hidden under the clip it didn’t pick up the brake cleaner until really close.

                                          Thank you everyone been a couple of stressful days but that’s a win and learn something on the way

                                          HOTSHOT IIIH S 2 Replies Last reply
                                          3
                                          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