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DT125R FORUM

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  4. Holley carbs!!...

Holley carbs!!...

Scheduled Pinned Locked Moved Carburetor
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  • S SpookDog

    alt text

    Anyone else got the extra hole?
    The pinhole above the tickover screw but below the power jet pipe? Or am I just special? 🤪 cause I’m guessing that it’s not factory 🤨 ...

    CalumC Offline
    CalumC Offline
    Calum
    wrote on last edited by
    #2

    @spookdog Looks like a casting flaw to me. Shouldn't be any hole there. Time to get some liquid metal epoxy and plug it up 😛

    Always Originate, Never Pirate!

    S 1 Reply Last reply
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    • CalumC Calum

      @spookdog Looks like a casting flaw to me. Shouldn't be any hole there. Time to get some liquid metal epoxy and plug it up 😛

      S Offline
      S Offline
      SpookDog
      wrote on last edited by SpookDog
      #3

      @Everyone with a brain, or just more sense than me

      If my airscrew on my carb has no (or very little) affect. Would this point towards a too small pilot jet that needs no extra air? I’ve been playing majic roundabouts with this for a while. I’ve found and fixed two separate potential air leaks to no avail.
      I also have a really bad transition between low to 1/4 throttle. It’s lumpy as feck, like it’s miss firing, then picks up fine. The only thing that I’ve done (that made it lumpy) is raise the needle to the fourth groove from the second. I’m wondering if the extra fuel earlier is making it too rich, kinda ‘chokey’?...

      Any thoughts or input would be well met 👍

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      • Stevie WonderS Offline
        Stevie WonderS Offline
        Stevie Wonder
        wrote on last edited by Stevie Wonder
        #4

        @spookdog I’ve probably mentioned I’m no carb expert and it’d surprise me if you haven’t tried it but have you tried putting the choke on partially or all the way at the boggy spot to see if it livens up a bit or just kills the bike due to over fuelling? It’s just a little trick I was taught.

        Also I was always taught to leave the air screw alone and then get everything else working. If your getting what you describe then it sounds like not enough fuel in the lower part of the circuit

        S 1 Reply Last reply
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        • Stevie WonderS Stevie Wonder

          @spookdog I’ve probably mentioned I’m no carb expert and it’d surprise me if you haven’t tried it but have you tried putting the choke on partially or all the way at the boggy spot to see if it livens up a bit or just kills the bike due to over fuelling? It’s just a little trick I was taught.

          Also I was always taught to leave the air screw alone and then get everything else working. If your getting what you describe then it sounds like not enough fuel in the lower part of the circuit

          S Offline
          S Offline
          SpookDog
          wrote on last edited by SpookDog
          #5

          @stevie-wonder
          No I haven’t tried to choke it at that point. I’ll give it a go, though I’ll have to find a nice quiet stretch of road. Reaching down for the choke and juggling the throttle is going to be fun! For me anyways! I’m no wheelie king zen type 😇 I’ve spent way too many years abusing my centre of gravity!...

          It’s a 28mm tm with a 525j needle Q2 needle jet, and a 22.5 pilot. The main was 180 which seems wrong. I put a 220 in but it made no difference (to the missy transition) I haven’t run it over half throttle yet as I’m running it in. I’m @ 222 miles believe it or not...

          S 1 Reply Last reply
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          • S SpookDog

            @stevie-wonder
            No I haven’t tried to choke it at that point. I’ll give it a go, though I’ll have to find a nice quiet stretch of road. Reaching down for the choke and juggling the throttle is going to be fun! For me anyways! I’m no wheelie king zen type 😇 I’ve spent way too many years abusing my centre of gravity!...

            It’s a 28mm tm with a 525j needle Q2 needle jet, and a 22.5 pilot. The main was 180 which seems wrong. I put a 220 in but it made no difference (to the missy transition) I haven’t run it over half throttle yet as I’m running it in. I’m @ 222 miles believe it or not...

            S Offline
            S Offline
            SpookDog
            wrote on last edited by
            #6

            @spookdog

            Do all dt’s ‘stutter’ at about 1/8~1/4 throttle? I’ve managed to get a good healthy colour on the plug, but I still get a rough spot there??!...

            Stevie WonderS 1 Reply Last reply
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            • S SpookDog

              @spookdog

              Do all dt’s ‘stutter’ at about 1/8~1/4 throttle? I’ve managed to get a good healthy colour on the plug, but I still get a rough spot there??!...

              Stevie WonderS Offline
              Stevie WonderS Offline
              Stevie Wonder
              wrote on last edited by
              #7

              @spookdog if they’re cold then yes, common trait for most oil injected bikes. But DTR’s in particular more then most love a good thrash or clutch of throttle to clear them out.

              I tend to give mine a good clutch of beans on starting then let her idle and that sorts it or wait 10 minutes of it idling to warm up then go for a gentle ride then enjoy that slight splutter at 1/8-1/4 throttle before zipping off into powerband

              S 1 Reply Last reply
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              • Stevie WonderS Stevie Wonder

                @spookdog if they’re cold then yes, common trait for most oil injected bikes. But DTR’s in particular more then most love a good thrash or clutch of throttle to clear them out.

                I tend to give mine a good clutch of beans on starting then let her idle and that sorts it or wait 10 minutes of it idling to warm up then go for a gentle ride then enjoy that slight splutter at 1/8-1/4 throttle before zipping off into powerband

                S Offline
                S Offline
                SpookDog
                wrote on last edited by SpookDog
                #8

                @stevie-wonder
                Mine does it when it’s warm. I just dropped the pilot jet down to a .20 and have a good colour, it was sooty black before. But I still don’t get any real response from the airscrew! So I left it at 1 & 1/2 turns. When I rev up there’s a stutter and it’s boggy when cruising in town @ 30-40...
                It’s a buzzkill cause I don’t know what the previous owner has done to the jetting. Plus I’m still running in (@350 miles!) and don’t want to fraggle rock the thing! 🗯

                S 1 Reply Last reply
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                • S SpookDog

                  @stevie-wonder
                  Mine does it when it’s warm. I just dropped the pilot jet down to a .20 and have a good colour, it was sooty black before. But I still don’t get any real response from the airscrew! So I left it at 1 & 1/2 turns. When I rev up there’s a stutter and it’s boggy when cruising in town @ 30-40...
                  It’s a buzzkill cause I don’t know what the previous owner has done to the jetting. Plus I’m still running in (@350 miles!) and don’t want to fraggle rock the thing! 🗯

                  S Offline
                  S Offline
                  SpookDog
                  wrote on last edited by
                  #9

                  The clutch of beans method should only ever be used on hire (or someone else’s) motors! It’s in the Haynes manual, honestly 🤞

                  I’ve not been above 5.5K revs yet! I’m taking running it in serious. If I knew the previous it might be different, but like I said, what with the mixture niggles I really don’t want to run it lean or rich...

                  S 1 Reply Last reply
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                  • S SpookDog

                    The clutch of beans method should only ever be used on hire (or someone else’s) motors! It’s in the Haynes manual, honestly 🤞

                    I’ve not been above 5.5K revs yet! I’m taking running it in serious. If I knew the previous it might be different, but like I said, what with the mixture niggles I really don’t want to run it lean or rich...

                    S Offline
                    S Offline
                    SpookDog
                    wrote on last edited by SpookDog
                    #10

                    Found a pinhole in the inlet manifold, gonna try and seal it up with sillyc#n# sealant. Because the rubber is still soft and supple I never tried spray testing the seal till now. Fine sprayed some brake cleaner on it and the revs ‘settled’ out. Once I’ve cured the leak (any one got a GOOD 3ET inlet manifold for sale?) I’m confident I’ll settle the pilot jet size & mixture 👍 ...

                    S 1 Reply Last reply
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                    • S SpookDog

                      Found a pinhole in the inlet manifold, gonna try and seal it up with sillyc#n# sealant. Because the rubber is still soft and supple I never tried spray testing the seal till now. Fine sprayed some brake cleaner on it and the revs ‘settled’ out. Once I’ve cured the leak (any one got a GOOD 3ET inlet manifold for sale?) I’m confident I’ll settle the pilot jet size & mixture 👍 ...

                      S Offline
                      S Offline
                      SpookDog
                      wrote on last edited by
                      #11

                      @spookdog

                      Anyone know if you can get tm28 slides in different cutaway sizes? If so, where?...
                      Cheers peeps!...

                      K 1 Reply Last reply
                      0
                      • S SpookDog

                        @spookdog

                        Anyone know if you can get tm28 slides in different cutaway sizes? If so, where?...
                        Cheers peeps!...

                        K Offline
                        K Offline
                        kevin
                        wrote on last edited by
                        #12

                        @spookdog you need to research which bikes use the Tm28 such as Tzr250 Tzr125 Gilera also used the Tm28ss but don’t know the model, I will have a rummage and see what I have got.

                        S 1 Reply Last reply
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                        • K kevin

                          @spookdog you need to research which bikes use the Tm28 such as Tzr250 Tzr125 Gilera also used the Tm28ss but don’t know the model, I will have a rummage and see what I have got.

                          S Offline
                          S Offline
                          SpookDog
                          wrote on last edited by
                          #13

                          @kevin
                          I want to go with a 2.0 or so. I don’t know the increment’s. I have a 2.5 fitted ATM...

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