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    Holley carbs!!...

    Carburetor
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    • S
      SpookDog last edited by 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 🤨 ...

      Calum 1 Reply Last reply Reply Quote 0
      • Calum
        Calum @SpookDog last edited by

        @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!

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        • S
          SpookDog @Calum last edited by SpookDog

          @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 Wonder
            Stevie Wonder last edited by 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

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              SpookDog @Stevie Wonder last edited by 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...

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              • S
                SpookDog @SpookDog last edited by

                @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??!...

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                • Stevie Wonder
                  Stevie Wonder @SpookDog last edited by

                  @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

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                  • S
                    SpookDog @Stevie Wonder last edited by 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! 🗯

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                    • S
                      SpookDog @SpookDog last edited by

                      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...

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                      • S
                        SpookDog @SpookDog last edited by 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 👍 ...

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                        • S
                          SpookDog @SpookDog last edited by

                          @spookdog

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

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                          • K
                            kevin @SpookDog last edited by

                            @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.

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                              SpookDog @kevin last edited by

                              @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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