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DT125R FORUM

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  4. So Close!...

So Close!...

Scheduled Pinned Locked Moved DTR
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  • M MadGyver
    5 Feb 2023, 21:17

    @SpookDog said in So Close!...:

    @MadGyver

    Cheers bud, I will check it out…

    Does anyone know how to find the CDI markings numbers to year? I’m sure I saw a page once that listed all the years of CDI and when they changed by their marked numbers. Also which ones were the least restricted? Any help is appreciated 🙂 …

    CDI 3NC no restriction,I ve revved up to 13500rpm on the road.

    S Offline
    S Offline
    SpookDog
    wrote on 5 Feb 2023, 22:47 last edited by SpookDog 2 May 2023, 23:44
    #410

    @MadGyver

    Really? What year bike? Mines a late 1988 (28mm flatslide) that came without the servo (3 wire) I’d like to know what I should have or can use. My CDI has no marking. I think I can use any 3 wire servo-CDI, but: Nothing is ever easy! 😵‍💫

    I’ve actually got a 3nc-00 93n CDI I brought for £25-30 off of fleabay. Has 10 (or 11 counting looped black wire) wires, just checked it out! I only hope it works!…
    Got a 4hw CDI as well…

    M 1 Reply Last reply 6 Feb 2023, 11:36
    0
    • S SpookDog
      5 Feb 2023, 22:47

      @MadGyver

      Really? What year bike? Mines a late 1988 (28mm flatslide) that came without the servo (3 wire) I’d like to know what I should have or can use. My CDI has no marking. I think I can use any 3 wire servo-CDI, but: Nothing is ever easy! 😵‍💫

      I’ve actually got a 3nc-00 93n CDI I brought for £25-30 off of fleabay. Has 10 (or 11 counting looped black wire) wires, just checked it out! I only hope it works!…
      Got a 4hw CDI as well…

      M Offline
      M Offline
      MadGyver
      wrote on 6 Feb 2023, 11:36 last edited by MadGyver 2 Jun 2023, 13:34
      #411

      @SpookDog said in So Close!...:

      @MadGyver

      Really? What year bike? Mines a late 1988 (28mm flatslide) that came without the servo (3 wire) I’d like to know what I should have or can use. My CDI has no marking. I think I can use any 3 wire servo-CDI, but: Nothing is ever easy! 😵‍💫

      I’ve actually got a 3nc-00 93n CDI I brought for £25-30 off of fleabay. Has 10 (or 11 counting looped black wire) wires, just checked it out! I only hope it works!…
      Got a 4hw CDI as well…

      It's a 1990 model as far as I found,3 wire servo, 3NC-00 cdi,28mm flatside carb.Registered here in Greece at 1993 but came as a used bike from another country,not European.Although it says 4BL on the frame.

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

      S 1 Reply Last reply 6 Feb 2023, 14:14
      0
      • M MadGyver
        6 Feb 2023, 11:36

        @SpookDog said in So Close!...:

        @MadGyver

        Really? What year bike? Mines a late 1988 (28mm flatslide) that came without the servo (3 wire) I’d like to know what I should have or can use. My CDI has no marking. I think I can use any 3 wire servo-CDI, but: Nothing is ever easy! 😵‍💫

        I’ve actually got a 3nc-00 93n CDI I brought for £25-30 off of fleabay. Has 10 (or 11 counting looped black wire) wires, just checked it out! I only hope it works!…
        Got a 4hw CDI as well…

        It's a 1990 model as far as I found,3 wire servo, 3NC-00 cdi,28mm flatside carb.Registered here in Greece at 1993 but came as a used bike from another country,not European.Although it says 4BL on the frame.

        S Offline
        S Offline
        SpookDog
        wrote on 6 Feb 2023, 14:14 last edited by
        #412

        @MadGyver
        Thank you bud! That’s the best info I’ve been able to find about early dtr RPMs’ and I’ve been searching! 🙂 …

        IMO, My bike feels like it’s reaching its max rpm with the valve closed before the the servo opens up. I’m thinking that if the servo opened 1000rpm earlier it would be a smooth transition. I could well be wrong though! 😛 …

        M 1 Reply Last reply 6 Feb 2023, 14:36
        0
        • S SpookDog
          6 Feb 2023, 14:14

          @MadGyver
          Thank you bud! That’s the best info I’ve been able to find about early dtr RPMs’ and I’ve been searching! 🙂 …

          IMO, My bike feels like it’s reaching its max rpm with the valve closed before the the servo opens up. I’m thinking that if the servo opened 1000rpm earlier it would be a smooth transition. I could well be wrong though! 😛 …

          M Offline
          M Offline
          MadGyver
          wrote on 6 Feb 2023, 14:36 last edited by MadGyver 2 Jun 2023, 14:40
          #413

          @SpookDog said in So Close!...:

          @MadGyver
          Thank you bud! That’s the best info I’ve been able to find about early dtr RPMs’ and I’ve been searching! 🙂 …

          IMO, My bike feels like it’s reaching its max rpm with the valve closed before the the servo opens up. I’m thinking that if the servo opened 1000rpm earlier it would be a smooth transition. I could well be wrong though! 😛 …

          For smoother operation search also the reed valve major component for that,see at my project topic for some info,down to the last posts.
          My bike was very ok until 8K but after that was explosive almost burnt my clutch disks.It revved really hard and instantly to the 12K with the boyesen dual stage.

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

          S 1 Reply Last reply 6 Feb 2023, 16:02
          0
          • M MadGyver
            6 Feb 2023, 14:36

            @SpookDog said in So Close!...:

            @MadGyver
            Thank you bud! That’s the best info I’ve been able to find about early dtr RPMs’ and I’ve been searching! 🙂 …

            IMO, My bike feels like it’s reaching its max rpm with the valve closed before the the servo opens up. I’m thinking that if the servo opened 1000rpm earlier it would be a smooth transition. I could well be wrong though! 😛 …

            For smoother operation search also the reed valve major component for that,see at my project topic for some info,down to the last posts.
            My bike was very ok until 8K but after that was explosive almost burnt my clutch disks.It revved really hard and instantly to the 12K with the boyesen dual stage.

            S Offline
            S Offline
            SpookDog
            wrote on 6 Feb 2023, 16:02 last edited by SpookDog 2 Jun 2023, 17:52
            #414

            @MadGyver
            Cheers bud, will do…

            One thing I’ve noticed with the stainless steel exhaust is it kinda ‘rings’ at certain revs, like a bell. It’s quite strange to get used to. I thought it was engine noise at first…
            Anyone else get that with HR or other stainless pipes?…

            PS another question: does the CDI tell the power valve when to open? Or does it just provide RPM info and the servo is hard wired to open at a certain RPM? This is 3 wire servo’s only. I understand that dtre 5 wire servo’s can be programmed if you have the right aftermarket ignition system, but doubt it’s relevant to early, pre 1996 models…

            PPS is there a manual for after 1993 TZRs? I have a Mikuni 28 flatslide (Yamaha, with the 12*deg slant & coolant pipes) that has different 1mm cutaway slide, needle jet & tube, ect, internal setup. I was told it was from a 4dl iirc, but I’d like to learn more about it properly…

            H 1 Reply Last reply 7 Feb 2023, 09:00
            0
            • S SpookDog
              6 Feb 2023, 16:02

              @MadGyver
              Cheers bud, will do…

              One thing I’ve noticed with the stainless steel exhaust is it kinda ‘rings’ at certain revs, like a bell. It’s quite strange to get used to. I thought it was engine noise at first…
              Anyone else get that with HR or other stainless pipes?…

              PS another question: does the CDI tell the power valve when to open? Or does it just provide RPM info and the servo is hard wired to open at a certain RPM? This is 3 wire servo’s only. I understand that dtre 5 wire servo’s can be programmed if you have the right aftermarket ignition system, but doubt it’s relevant to early, pre 1996 models…

              PPS is there a manual for after 1993 TZRs? I have a Mikuni 28 flatslide (Yamaha, with the 12*deg slant & coolant pipes) that has different 1mm cutaway slide, needle jet & tube, ect, internal setup. I was told it was from a 4dl iirc, but I’d like to learn more about it properly…

              H Offline
              H Offline
              HOTSHOT III
              wrote on 7 Feb 2023, 09:00 last edited by HOTSHOT III 2 Jul 2023, 09:57
              #415

              @SpookDog said in So Close!...:

              PS another question: does the CDI tell the power valve when to open? Or does it just provide RPM info and the servo is hard wired to open at a certain RPM? This is 3 wire servo’s only. I understand that dtre 5 wire servo’s can be programmed if you have the right aftermarket ignition system, but doubt it’s relevant to early, pre 1996 models…

              On 3-wire servo systems (3BN, 3NC and 3MB) the CDI just sends engine speed information to the servo via the black/yellow wire (i.e it pulses once per crank revolution like the crank sensor on a car). Inside the 3-wire servo there's a small onboard computer (just a PCB) which interprets this and decides how far the valve should open at a given engine speed. This is the reason the 3-wire DTR servos are so expensive and difficult to find (IIRC almost every other YPVS- and EXUP-equipped Yamaha runs on the 5-wire servo system where the CDI takes care of all this and the servo is just a servo like the ones you get on a radio-controlled model).

              I once bought a 3NC where the 3-wire servo did its cleaning cycle when switching on the ignition, but didn't respond to engine speed; a replacement servo cured it meaning the PCB has two separate circuits, one for the cleaning cycle and one for engine speed. If you apply 12v to the black and brown wires with the 3-wire servo removed from the bike altogether, it still performs its cleaning cycle (brown is +ve main feed from the ignition switch on Yamahas). I once watched a Suzuki mechanic use a piece of test equipment to simulate an RGV250 revving to over 14000rpm to test powervalve operation (the electronic tacho was displaying the rpm and the plugs were sparking and everything even though it wasn't actually running). Zeeltronic ignitions come wired for either 3- or 5-wire servos; they advise running a 5-wire because it's more tuneable. There's also a guide on their site showing how to turn a 3-wire servo into a 5-wire (this allows you to remove and store the PCB and return the servo to a 3-wire if you ever want to go back to the stock CDI).

              Not sure about the CDI for the earlier round slide carb '88 bikes (I think they're etched 3BD but I've never seen one) but the flat slide carb 3-wire servo CDI units are either 3NC or 3MB and the wiring is:

              3NC
              Black/yellow female bullet
              Blue/yellow female bullet
              Black/white female bullet
              Orange female spade
              Blue and sky blue female 2-pin connector
              Black and white/red female 2-pin connector
              Black/red and green/white male 2-pin connector

              3MB
              Black/yellow female bullet
              Blue/yellow female bullet
              Black/white female bullet
              Orange female spade
              Blue male bullet
              Black male bullet (2 black wires into one terminal)
              Black and white/red female 2-pin connector
              Black/red and green/white male 2-pin connector

              3NC and 3MB engines are mechanically identical, both should rev to around 10.5k stock but I found the 3MB to have a lot more power at the same engine speeds; the 3NC still went well, was fun to ride, revved out OK etc. but there's certain places on my regular rides (steep hills etc.) where the 3MB just keeps revving whilst the 3NC runs out of puff leading me to suspect the 3MB ignition advance curve is different. Unfortunately 3NC and 3MB looms are also different meaning you can't just bung a 3MB CDI on a 3NC bike (hence my decision to opt for the Zeeltronic/5-wire servo setup on my 3NC which has now been sold).

              This could be for a number of reasons; my 3MB is the highest mileage DTR anyone has ever seen with nearly 70,000km of Paris commuting racked up but when I replaced the head gasket not long after buying it I measured the bore to be standard 56mm leading me to suspect the previous owner had the engine rebuilt (possibly with a non-OEM head gasket) just before selling it after umpteen rebores. And interestingly I changed the head from a 3BN to a 3MB at the same time and it made no difference (i.e it was fast even with a 3BN head). But I've owned two sub-6000 mile French import 3NCs (a '93 and a '98) and they both felt exactly the same. And all three bikes ran stock jetting (including having the power jet connected) according to the Yamaha France parts lookup where you enter your VIN number and they tell you the jet sizes for that particular bike by part number.

              S 1 Reply Last reply 7 Feb 2023, 15:44
              1
              • H HOTSHOT III
                7 Feb 2023, 09:00

                @SpookDog said in So Close!...:

                PS another question: does the CDI tell the power valve when to open? Or does it just provide RPM info and the servo is hard wired to open at a certain RPM? This is 3 wire servo’s only. I understand that dtre 5 wire servo’s can be programmed if you have the right aftermarket ignition system, but doubt it’s relevant to early, pre 1996 models…

                On 3-wire servo systems (3BN, 3NC and 3MB) the CDI just sends engine speed information to the servo via the black/yellow wire (i.e it pulses once per crank revolution like the crank sensor on a car). Inside the 3-wire servo there's a small onboard computer (just a PCB) which interprets this and decides how far the valve should open at a given engine speed. This is the reason the 3-wire DTR servos are so expensive and difficult to find (IIRC almost every other YPVS- and EXUP-equipped Yamaha runs on the 5-wire servo system where the CDI takes care of all this and the servo is just a servo like the ones you get on a radio-controlled model).

                I once bought a 3NC where the 3-wire servo did its cleaning cycle when switching on the ignition, but didn't respond to engine speed; a replacement servo cured it meaning the PCB has two separate circuits, one for the cleaning cycle and one for engine speed. If you apply 12v to the black and brown wires with the 3-wire servo removed from the bike altogether, it still performs its cleaning cycle (brown is +ve main feed from the ignition switch on Yamahas). I once watched a Suzuki mechanic use a piece of test equipment to simulate an RGV250 revving to over 14000rpm to test powervalve operation (the electronic tacho was displaying the rpm and the plugs were sparking and everything even though it wasn't actually running). Zeeltronic ignitions come wired for either 3- or 5-wire servos; they advise running a 5-wire because it's more tuneable. There's also a guide on their site showing how to turn a 3-wire servo into a 5-wire (this allows you to remove and store the PCB and return the servo to a 3-wire if you ever want to go back to the stock CDI).

                Not sure about the CDI for the earlier round slide carb '88 bikes (I think they're etched 3BD but I've never seen one) but the flat slide carb 3-wire servo CDI units are either 3NC or 3MB and the wiring is:

                3NC
                Black/yellow female bullet
                Blue/yellow female bullet
                Black/white female bullet
                Orange female spade
                Blue and sky blue female 2-pin connector
                Black and white/red female 2-pin connector
                Black/red and green/white male 2-pin connector

                3MB
                Black/yellow female bullet
                Blue/yellow female bullet
                Black/white female bullet
                Orange female spade
                Blue male bullet
                Black male bullet (2 black wires into one terminal)
                Black and white/red female 2-pin connector
                Black/red and green/white male 2-pin connector

                3NC and 3MB engines are mechanically identical, both should rev to around 10.5k stock but I found the 3MB to have a lot more power at the same engine speeds; the 3NC still went well, was fun to ride, revved out OK etc. but there's certain places on my regular rides (steep hills etc.) where the 3MB just keeps revving whilst the 3NC runs out of puff leading me to suspect the 3MB ignition advance curve is different. Unfortunately 3NC and 3MB looms are also different meaning you can't just bung a 3MB CDI on a 3NC bike (hence my decision to opt for the Zeeltronic/5-wire servo setup on my 3NC which has now been sold).

                This could be for a number of reasons; my 3MB is the highest mileage DTR anyone has ever seen with nearly 70,000km of Paris commuting racked up but when I replaced the head gasket not long after buying it I measured the bore to be standard 56mm leading me to suspect the previous owner had the engine rebuilt (possibly with a non-OEM head gasket) just before selling it after umpteen rebores. And interestingly I changed the head from a 3BN to a 3MB at the same time and it made no difference (i.e it was fast even with a 3BN head). But I've owned two sub-6000 mile French import 3NCs (a '93 and a '98) and they both felt exactly the same. And all three bikes ran stock jetting (including having the power jet connected) according to the Yamaha France parts lookup where you enter your VIN number and they tell you the jet sizes for that particular bike by part number.

                S Offline
                S Offline
                SpookDog
                wrote on 7 Feb 2023, 15:44 last edited by SpookDog 2 Jul 2023, 18:21
                #416

                @HOTSHOT-III

                Thank you, this is the good stuff that I need to know. I have another 3 wire servo that opens & closes much (3x slower, I thought the motor was fubar) slower than the one I’ve fitted to my 88. I’m going to try fitting it and see if it opens at something useful to me. I remember reading that some open as late as 8K+ (tzr) & some as low as 6-7…

                I noticed no performance difference between the MB & BN heads either, at all. The 3bn was actually a lower CC (measured with liquid) than the MB which would make it higher compression! Go figure 😐 …

                C 1 Reply Last reply 7 Feb 2023, 20:39
                1
                • S SpookDog
                  7 Feb 2023, 15:44

                  @HOTSHOT-III

                  Thank you, this is the good stuff that I need to know. I have another 3 wire servo that opens & closes much (3x slower, I thought the motor was fubar) slower than the one I’ve fitted to my 88. I’m going to try fitting it and see if it opens at something useful to me. I remember reading that some open as late as 8K+ (tzr) & some as low as 6-7…

                  I noticed no performance difference between the MB & BN heads either, at all. The 3bn was actually a lower CC (measured with liquid) than the MB which would make it higher compression! Go figure 😐 …

                  C Offline
                  C Offline
                  Calum
                  wrote on 7 Feb 2023, 20:39 last edited by
                  #417

                  @SpookDog This geezer seemed to have differing opinions.

                  https://yamahaclub.com/forums/topic/20583-de-restricting-my-dt125r/?page=6

                  And noted his 3MB head made more compression measured with a guage than the 3BN. I know others also remarked at how they noticed more mid-range.

                  Years ago when I was a wee lad and I went from a restricted CDI to green & black wire earthed and eventually to a Zeeltronic ignition system, I noticed no performance increase. It was only when I went back to stock ignition when my CDI developed a fault that I really appreciated how good the Zeeltronic was, then earthed the Green & Black wire to be surprised at what a difference it made.

                  The thing is, the difference might be quite small and hard to detect, it's not like slapping on the 170 kit and increasing the displacement by 30%+

                  Always Originate, Never Pirate!

                  S 1 Reply Last reply 8 Feb 2023, 16:43
                  0
                  • C Calum
                    7 Feb 2023, 20:39

                    @SpookDog This geezer seemed to have differing opinions.

                    https://yamahaclub.com/forums/topic/20583-de-restricting-my-dt125r/?page=6

                    And noted his 3MB head made more compression measured with a guage than the 3BN. I know others also remarked at how they noticed more mid-range.

                    Years ago when I was a wee lad and I went from a restricted CDI to green & black wire earthed and eventually to a Zeeltronic ignition system, I noticed no performance increase. It was only when I went back to stock ignition when my CDI developed a fault that I really appreciated how good the Zeeltronic was, then earthed the Green & Black wire to be surprised at what a difference it made.

                    The thing is, the difference might be quite small and hard to detect, it's not like slapping on the 170 kit and increasing the displacement by 30%+

                    S Offline
                    S Offline
                    SpookDog
                    wrote on 8 Feb 2023, 16:43 last edited by SpookDog 2 Sept 2023, 10:19
                    #418

                    What’s your take on the Romeu Henrique pipe (or any stainless steel pipe) Do you get a ringing/humming at certain revs or speeds? Like a cross between ‘blowing across a open bottle top’ & one of those weird metal bowls that ring when you rub around the rim…

                    PS, on the MB v BN front, I don’t think there’s any real difference between them, not enough to call one ‘performance’ and the other ‘restrictive’ or to even argue about anyways. I think maybe it (the 3bn) seemed like a good idea at the time, but didn’t stand the test 🙂
                    Either way, I’d always pick the 3mb head if given the choice! 😛 …

                    S 1 Reply Last reply 9 Feb 2023, 22:49
                    0
                    • S SpookDog
                      8 Feb 2023, 16:43

                      What’s your take on the Romeu Henrique pipe (or any stainless steel pipe) Do you get a ringing/humming at certain revs or speeds? Like a cross between ‘blowing across a open bottle top’ & one of those weird metal bowls that ring when you rub around the rim…

                      PS, on the MB v BN front, I don’t think there’s any real difference between them, not enough to call one ‘performance’ and the other ‘restrictive’ or to even argue about anyways. I think maybe it (the 3bn) seemed like a good idea at the time, but didn’t stand the test 🙂
                      Either way, I’d always pick the 3mb head if given the choice! 😛 …

                      S Offline
                      S Offline
                      SpookDog
                      wrote on 9 Feb 2023, 22:49 last edited by
                      #419

                      Sweet! New thing!…

                      Speedo has stopped working, happened all of a sudden. Cable is good, stuck a small screwdriver in the bottom of the speedo and spun it and the needle goes up, so I’m guessing it’s the impossible to find gear at the wheel. What are the chances of it failing all of a sudden with no warning? I would of expected slow failure as the cogs teeth gave up the ghost? Strange thing is the speedo bulb went at the same time 👻 …

                      M 1 Reply Last reply 10 Feb 2023, 10:40
                      0
                      • S SpookDog
                        9 Feb 2023, 22:49

                        Sweet! New thing!…

                        Speedo has stopped working, happened all of a sudden. Cable is good, stuck a small screwdriver in the bottom of the speedo and spun it and the needle goes up, so I’m guessing it’s the impossible to find gear at the wheel. What are the chances of it failing all of a sudden with no warning? I would of expected slow failure as the cogs teeth gave up the ghost? Strange thing is the speedo bulb went at the same time 👻 …

                        M Offline
                        M Offline
                        markus.w
                        wrote on 10 Feb 2023, 10:40 last edited by
                        #420

                        @SpookDog the speedo drive at the wheel is quite a common failure on these. With the cable removed from the clocks you can spin the wheel and check if the inner moves. They are still available new from Fowlers for about £50. Strange that the bulb stopped working same time but surely that has to be a coincidence?

                        S 1 Reply Last reply 10 Feb 2023, 18:19
                        0
                        • M markus.w
                          10 Feb 2023, 10:40

                          @SpookDog the speedo drive at the wheel is quite a common failure on these. With the cable removed from the clocks you can spin the wheel and check if the inner moves. They are still available new from Fowlers for about £50. Strange that the bulb stopped working same time but surely that has to be a coincidence?

                          S Offline
                          S Offline
                          SpookDog
                          wrote on 10 Feb 2023, 18:19 last edited by SpookDog 2 Oct 2023, 18:20
                          #421

                          @markus-w

                          Yeah, the hub drive has failed, it did have a bit of a needle wobble at 50-55 before for a while, as I’ve now remembered! My bad memory is the main reason I document so much info in this thread. I used to rite it down on bits of cardboard (aka my work bench) and pads, but I was always loosing them or forgetting to date them…

                          I checked the cable was sound then removed the speedo, put a bit of tape on the end of the top inner and checked to see if it was spinning, alas it was just sat there, useless as me 😐 …

                          M 1 Reply Last reply 10 Feb 2023, 19:11
                          0
                          • S SpookDog
                            10 Feb 2023, 18:19

                            @markus-w

                            Yeah, the hub drive has failed, it did have a bit of a needle wobble at 50-55 before for a while, as I’ve now remembered! My bad memory is the main reason I document so much info in this thread. I used to rite it down on bits of cardboard (aka my work bench) and pads, but I was always loosing them or forgetting to date them…

                            I checked the cable was sound then removed the speedo, put a bit of tape on the end of the top inner and checked to see if it was spinning, alas it was just sat there, useless as me 😐 …

                            M Offline
                            M Offline
                            markus.w
                            wrote on 10 Feb 2023, 19:11 last edited by
                            #422

                            @SpookDog tell me about it bud, I've mislaid a note book with so much Important information in it. Nightmare.

                            S 1 Reply Last reply 10 Feb 2023, 20:44
                            0
                            • M markus.w
                              10 Feb 2023, 19:11

                              @SpookDog tell me about it bud, I've mislaid a note book with so much Important information in it. Nightmare.

                              S Offline
                              S Offline
                              SpookDog
                              wrote on 10 Feb 2023, 20:44 last edited by SpookDog 2 Oct 2023, 22:05
                              #423

                              There’s a tiny pin that holds the brass insert into the gear housing (that the speedo cable screws onto). Has anyone ever taken the worm drive out? I can’t see if it’s a tiny Allen grub screw or a press pin that needs to be drilled out? Anyone help?…

                              The worm drive has seized on mine and I want to take it out and free it off…
                              The worm drive (that the cable fits into @ the hub) has seized solid, the ring gear is intact, but the 3 tabbed/pronged ring has had the tabs bent down on it. If I can dismantle the worm gear and get it turning again I can save the unit. It’s just getting out the pin/grub screw thing so I can remove the brass threaded cap (that the speedo cable screws to) and get to the worm drive/shaft…

                              H 1 Reply Last reply 11 Feb 2023, 06:58
                              0
                              • S SpookDog
                                10 Feb 2023, 20:44

                                There’s a tiny pin that holds the brass insert into the gear housing (that the speedo cable screws onto). Has anyone ever taken the worm drive out? I can’t see if it’s a tiny Allen grub screw or a press pin that needs to be drilled out? Anyone help?…

                                The worm drive has seized on mine and I want to take it out and free it off…
                                The worm drive (that the cable fits into @ the hub) has seized solid, the ring gear is intact, but the 3 tabbed/pronged ring has had the tabs bent down on it. If I can dismantle the worm gear and get it turning again I can save the unit. It’s just getting out the pin/grub screw thing so I can remove the brass threaded cap (that the speedo cable screws to) and get to the worm drive/shaft…

                                H Offline
                                H Offline
                                HOTSHOT III
                                wrote on 11 Feb 2023, 06:58 last edited by HOTSHOT III 2 Nov 2023, 07:00
                                #424

                                @SpookDog It's a hollow roll pin that holds the worm drive into the speedo drive housing. I've repaired a couple of plastic ones, IIRC I drilled a small hole into the housing from the inside enabling me to tap out the pin (I think I might have even made something smaller in diameter than my smallest punch to do this). Then once I got it all apart and freed off I used a split pin to keep it all together on reassembly. Also bought a load of shims the correct ID/OD as the worm drive eats into the plastic as it rotates. And you can get the seal where the unit fits onto the wheel hub from a bearing shop, I think Ashley Bearings in Poole are pretty good. Well worth replacing as they leak sometimes, and you can get ones with a garter spring (better than OEM) meaning you can really pack the unit with grease once it's fixed.

                                An aluminium one might be more difficult as there's potential for the roll pin to seize into the housing so maybe a bit of heat after you've drilled it?

                                S 1 Reply Last reply 11 Feb 2023, 15:41
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                                • H HOTSHOT III
                                  11 Feb 2023, 06:58

                                  @SpookDog It's a hollow roll pin that holds the worm drive into the speedo drive housing. I've repaired a couple of plastic ones, IIRC I drilled a small hole into the housing from the inside enabling me to tap out the pin (I think I might have even made something smaller in diameter than my smallest punch to do this). Then once I got it all apart and freed off I used a split pin to keep it all together on reassembly. Also bought a load of shims the correct ID/OD as the worm drive eats into the plastic as it rotates. And you can get the seal where the unit fits onto the wheel hub from a bearing shop, I think Ashley Bearings in Poole are pretty good. Well worth replacing as they leak sometimes, and you can get ones with a garter spring (better than OEM) meaning you can really pack the unit with grease once it's fixed.

                                  An aluminium one might be more difficult as there's potential for the roll pin to seize into the housing so maybe a bit of heat after you've drilled it?

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                                  SpookDog
                                  wrote on 11 Feb 2023, 15:41 last edited by SpookDog 2 Nov 2023, 15:43
                                  #425

                                  @HOTSHOT-III

                                  Ashley bearings, in parkstone sill going? I wish I’d known that before. Cheers bud…

                                  H S 2 Replies Last reply 11 Feb 2023, 17:17
                                  0
                                  • S SpookDog
                                    11 Feb 2023, 15:41

                                    @HOTSHOT-III

                                    Ashley bearings, in parkstone sill going? I wish I’d known that before. Cheers bud…

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                                    HOTSHOT III
                                    wrote on 11 Feb 2023, 17:17 last edited by
                                    #426

                                    @SpookDog Yes mate but they've moved, just off Holes Bay Road now

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                                    • S SpookDog
                                      11 Feb 2023, 15:41

                                      @HOTSHOT-III

                                      Ashley bearings, in parkstone sill going? I wish I’d known that before. Cheers bud…

                                      S Offline
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                                      SpookDog
                                      wrote on 11 Feb 2023, 23:44 last edited by SpookDog 2 Nov 2023, 23:46
                                      #427

                                      This is the pin holding in the brass threaded coupling

                                      alt text

                                      You can see it’s possible to drill from the rear but it’s such a small diameter. If I do drill it from the rear I could use what’s left of the pin and drift it in with a micro punch afterwards…

                                      alt text

                                      I would rather mend & resurrect the original part just because I’m a mean, stubborn git! Besides these genuine aluminium parts are going for fucking ridiculous prices! Some people have no (or @ least less than me) shame! I’ve seen nearly £120 asked for 😗 …

                                      S 1 Reply Last reply 11 Feb 2023, 23:48
                                      0
                                      • S SpookDog
                                        11 Feb 2023, 23:44

                                        This is the pin holding in the brass threaded coupling

                                        alt text

                                        You can see it’s possible to drill from the rear but it’s such a small diameter. If I do drill it from the rear I could use what’s left of the pin and drift it in with a micro punch afterwards…

                                        alt text

                                        I would rather mend & resurrect the original part just because I’m a mean, stubborn git! Besides these genuine aluminium parts are going for fucking ridiculous prices! Some people have no (or @ least less than me) shame! I’ve seen nearly £120 asked for 😗 …

                                        S Offline
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                                        SpookDog
                                        wrote on 11 Feb 2023, 23:48 last edited by SpookDog 2 Nov 2023, 23:55
                                        #428

                                        @SpookDog

                                        I’m assuming that the brass coupling has a groove in it that the pin ‘bites’ into?…

                                        PS: no input on the stainless steel pipe? I hope I haven’t caused offence! I know that I can be quite abrasive sometimes when I drink the Brew. Please, just don’t take it personally. I’m tetchy with the World in general, not specifically 🙂 not on purpose, anyways 😘 …

                                        H 2 Replies Last reply 12 Feb 2023, 08:09
                                        0
                                        • S SpookDog
                                          11 Feb 2023, 23:48

                                          @SpookDog

                                          I’m assuming that the brass coupling has a groove in it that the pin ‘bites’ into?…

                                          PS: no input on the stainless steel pipe? I hope I haven’t caused offence! I know that I can be quite abrasive sometimes when I drink the Brew. Please, just don’t take it personally. I’m tetchy with the World in general, not specifically 🙂 not on purpose, anyways 😘 …

                                          H Offline
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                                          HOTSHOT III
                                          wrote on 12 Feb 2023, 08:09 last edited by
                                          #429

                                          @SpookDog Yes there's a groove in the brass coupling for the pin to retain it. If you can get the roll pin out intact it would be perfectly in order to re-use it IMO, although it might not fit as tightly as when installed by the factory hence my decision to use a split pin the same size.

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