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  4. Bought DT125X, cannot get it to start? Spark, fuel OK

Bought DT125X, cannot get it to start? Spark, fuel OK

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enginedt125x
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  • L Offline
    L Offline
    Lorant2
    wrote on last edited by Lorant2
    #6

    I just measured the alternator coils.
    -Pickup coil is 285 Ohm (should be between 280-420) so its ok.

    -Source coil is 750 Ohm (should be 192-288 ohm) so I went further:

    --> removed the left side cover (in DE06 the magneto stays on the crankshaft and the alternator stays in the cover)
    --I saw that 3 wires are connected, there is 2 soldering on one of the sides, measured that and it is ~749 Ohm, so it is not the wire that is broken or connections.

    ->Also, that source coil has gotten loose off its "iron" base, so I guess that is the problem here.

    -2004 alternator
    It has a lot less coils so I guess I cant replace it and also it was fixed on the engine rather than cover.

    2004-onwards alternator
    The cost is hella lot 😞 And there is no guarantee that it will work.

    What do you guys think, can a specialist recoil that source coil for me? Or is there any other cheaper way to repair this?

    BTW thank you for your answers! 🙂

    EDIT:
    TDR91-02 alternator
    It looks the same as mine, even the connections, and ebay page also says that it is compatible with the DTX, I guess it is compatible because both have starters and Yamaha just used the TDR base on the later DT's. Would this mean that I can search a guy locally with a cheap torn down TDR and replace it?

    EDIT2:
    Imgur pictures of the coil

    EDIT3:
    GDrive video of the loose coil

    EDIT4:
    Talked to 2 guys, one said that it is common among newer DT ignitions to go faulty, and that a working stator is really rare and expensive. He recommends me to convert to some old ignition, I can even keep the e-starter, I need CDI, stator, magneto, regulator and wire harness. All this he can give me to 100 euros cost. What do you think?

    1 Reply Last reply
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    • L Lorant2

      Hey,

      Now, here's what I tried:
      -Cleaned air filter
      -Cleaned carburetor (It wasn't that dirty) (Has 17,5 air and 220 MJ in it which I think will be too small, considered that the snorkel is removed)
      -Cleaned battery + and - terminals, on the relay etc, fuse is ok.
      -Removed ignition coil from frame and cleaned terminals, and I measured it with Ohm meter:
      -->Primary: 0,5 ohm (manual says that it should be 0,23 ohm, so would this mean that the coil is faulty?)
      -->Secondary: 8kOhm (manual says should be 7.9 So i guess this is ok)
      -Spark plug is BR8EG (I will upgrade to B9ES soon) but I think it was replaced when the engine was rebuilt as it is clean.
      -Measured plug cap, it has 5.4 kOhm which is great.

      Now, I have strong spark on the plug, white or bright blue-ish color. I can even hear it popping. I tried injecting cold-starting spray and even a little fuel in the cylinder and bump starting it with a help, but it just does not want to start.

      When I put the side stand down or flip the switch to "off", spark is gone so I guess these switches are ok and neutral works also.

      Now one thing I haven't tried and I can think of: The petrol I'm using is still the one that is in the bike, I dont know how old is it, max 6 months I guess but it isn't stinking like old petrol does. I think that when the engine was rebuilt, they replaced crank seals so that won't need attention. I don't have compression meter but with two people we can barely do the bump starting so I guess it should start.

      Background story:
      I just bought a 2006 DT125X 2 weeks ago. The seller told me that the bike wasn't started for 3 months, and that the engine got a full rebuild at the official local Yamaha service 90km ago (the trip counter was zeroed when the rebuild was done) I went to see the bike, he told me that the battery was broken so I brought a 4Ah battery with myself which was not enough for the starter to spin for long. We tried to start it off a car but the starter motor broke (it turned out when I got home and disassembled the motor that the coil is broken inside, so I ordered a new one off ebay, until then I have to bump start the bike somehow. We tried bump starting it there but with no success. Despite the non starting bike, I got a good deal on it, and overall the bike is almost in mint condition, with no major fabrications. Later it turned out that it has a Gianelli resonator with stock silencer on it.

      Now, my main concern is this line:
      -->Primary: 0,5 ohm (manual says that it should be 0,23 ohm, so would this mean that the coil is faulty?)
      Do you have any other ideas, please?

      B Offline
      B Offline
      Bananper
      wrote on last edited by
      #7

      @Lorant2 BR8EG and B9es is not the correct spark plug. You should use BR8ES or BR9ES. Could be your issue.

      CalumC 1 Reply Last reply
      2
      • B Bananper

        @Lorant2 BR8EG and B9es is not the correct spark plug. You should use BR8ES or BR9ES. Could be your issue.

        CalumC Offline
        CalumC Offline
        Calum
        wrote on last edited by
        #8

        @Bananper Yeah I wasn't convinced that either, but it's been so long since I've worked on the DT I had forgotten.

        Always Originate, Never Pirate!

        1 Reply Last reply
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        • L Offline
          L Offline
          Lorant2
          wrote on last edited by
          #9

          Okay, I will try it then, but I guess the yamaha service put it in. On the internet I found out that I EG differs only from ES that it is a "racing" type plug with a thinner electrode that is less likely to get fouled. But I will try fresh fuel and Br9es when I have time.

          1 Reply Last reply
          0
          • L Offline
            L Offline
            Lorant2
            wrote on last edited by
            #10

            Got the new stator, still can't bump start it. The only difference is that I inject fuel at the plug, It will try to start for a few strokes. Also got the new plug, BR9ES with 0.6mm gap. Stripped down the carb again, it is clean, and tried it with fresh fuel, still nothing. Intake manifold looks ok, and tried to see inside with flashlight, and membrane looks okay too. If I take out the plug, it is not soaking in fuel, so it is not getting fuel, despite trying to bump it with choke on. I am hopeless now. Compression is okay I think because it is really hard to push even for two people.

            NINJAN 1 Reply Last reply
            0
            • L Lorant2

              Got the new stator, still can't bump start it. The only difference is that I inject fuel at the plug, It will try to start for a few strokes. Also got the new plug, BR9ES with 0.6mm gap. Stripped down the carb again, it is clean, and tried it with fresh fuel, still nothing. Intake manifold looks ok, and tried to see inside with flashlight, and membrane looks okay too. If I take out the plug, it is not soaking in fuel, so it is not getting fuel, despite trying to bump it with choke on. I am hopeless now. Compression is okay I think because it is really hard to push even for two people.

              NINJAN Offline
              NINJAN Offline
              NINJA
              wrote on last edited by
              #11

              @Lorant2 Is the plug sparking? Take it out, connect it to the HT lead and place the tip against a metal surface. Crank the bike with the kick starter and look for a spark, it will be very visible for a split second. If there's a spark then the plug is getting voltage, if there's nothing then you have an electrical problem.

              SEDUCED BY THE DARK SIDE!!!

              L 1 Reply Last reply
              0
              • NINJAN NINJA

                @Lorant2 Is the plug sparking? Take it out, connect it to the HT lead and place the tip against a metal surface. Crank the bike with the kick starter and look for a spark, it will be very visible for a split second. If there's a spark then the plug is getting voltage, if there's nothing then you have an electrical problem.

                L Offline
                L Offline
                Lorant2
                wrote on last edited by
                #12

                @NINJA I dont have a kickstarter. But I can check the spark by putting it in 6. and bumping the bike whilist looking at the spark. With the previous stator it was whiteish as I have written it, but now it is more of a blue.

                NINJAN 1 Reply Last reply
                0
                • L Lorant2

                  @NINJA I dont have a kickstarter. But I can check the spark by putting it in 6. and bumping the bike whilist looking at the spark. With the previous stator it was whiteish as I have written it, but now it is more of a blue.

                  NINJAN Offline
                  NINJAN Offline
                  NINJA
                  wrote on last edited by
                  #13

                  @Lorant2 OK that's fine, so you're getting a spark and fuel, what's the air situation? Is the carb working OK?

                  SEDUCED BY THE DARK SIDE!!!

                  L 1 Reply Last reply
                  0
                  • NINJAN NINJA

                    @Lorant2 OK that's fine, so you're getting a spark and fuel, what's the air situation? Is the carb working OK?

                    L Offline
                    L Offline
                    Lorant2
                    wrote on last edited by
                    #14

                    @NINJA I cleaned it completely, even removed the atomiser tube to make sure the holes arent blocked. Gaskets are fine it is not leaking and fuel level is correct. Has 17.5 air jet and 220 main jet which might be small considering that it has gianelli but it shouldn't be a problem to start it, especially since it has run with this setup for the previous owner. Power valve servo works as it checks, and it is set to the mark on the cylinder.

                    NINJAN 1 Reply Last reply
                    1
                    • J Offline
                      J Offline
                      Jens Eskildsen
                      wrote on last edited by
                      #15

                      Did you clean the choke passageway in the bowl?

                      1 Reply Last reply
                      1
                      • J Offline
                        J Offline
                        Jens Eskildsen
                        wrote on last edited by
                        #16

                        Also, have a look at the reedvalves for broken or torn reeds.

                        1 Reply Last reply
                        1
                        • L Lorant2

                          @NINJA I cleaned it completely, even removed the atomiser tube to make sure the holes arent blocked. Gaskets are fine it is not leaking and fuel level is correct. Has 17.5 air jet and 220 main jet which might be small considering that it has gianelli but it shouldn't be a problem to start it, especially since it has run with this setup for the previous owner. Power valve servo works as it checks, and it is set to the mark on the cylinder.

                          NINJAN Offline
                          NINJAN Offline
                          NINJA
                          wrote on last edited by
                          #17

                          @Lorant2 Sounds daft but it happens more than people care to admit too. Is the engine cut-off switch activated? If it's turned 'off' then check the wiring, is there an earth to it, check that to see if its rusty???

                          SEDUCED BY THE DARK SIDE!!!

                          1 Reply Last reply
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                          • L Offline
                            L Offline
                            Lorant2
                            wrote on last edited by
                            #18

                            I checked the choke and it is not blocked, I blew it eith compressor. I will have a look at the reeds the following day. But I took a picture inside the intake manifold and it looks ok, I will have a look if it has increased gap then I will replace it, they are moving freely as I touched it gently with my hands. I will check if I can see through it, but then again that would cause flooding I think and my plug is not oily at all after bump starting it for meters.

                            NINJAN 1 Reply Last reply
                            0
                            • L Offline
                              L Offline
                              Lorant2
                              wrote on last edited by
                              #19

                              I cleaned all the earths a week ago when I was diagnosing the starter motor. The earth is clean on the battery, on the engine, on the HT coil and on the regulator too. If I set kill switch to off, then I dont have any spark, neither if I let my side stand down.

                              1 Reply Last reply
                              0
                              • L Lorant2

                                I checked the choke and it is not blocked, I blew it eith compressor. I will have a look at the reeds the following day. But I took a picture inside the intake manifold and it looks ok, I will have a look if it has increased gap then I will replace it, they are moving freely as I touched it gently with my hands. I will check if I can see through it, but then again that would cause flooding I think and my plug is not oily at all after bump starting it for meters.

                                NINJAN Offline
                                NINJAN Offline
                                NINJA
                                wrote on last edited by
                                #20

                                @Lorant2 So if the kill switch is in the 'off' position, aka not turned on and the side stand is up - then you get a spark???

                                SEDUCED BY THE DARK SIDE!!!

                                1 Reply Last reply
                                1
                                • L Offline
                                  L Offline
                                  Lorant2
                                  wrote on last edited by
                                  #21

                                  I mean that it works as it is intended. I turn the ignition key to on, power checks, and the kill switch is set to "run" I guess (I think it is pressed from the top to the bottom), anyway it is working as it is written on it. I believe this is not an electrical issue anymore, my plug is just not soaking in fuel and oil as it should despite the (I think) big compression. Tomorrow I will also have a friend to come over and we will check the exact PSI compression, what should be a correct value? Above 100, with full open throttle?

                                  NINJAN 1 Reply Last reply
                                  0
                                  • L Lorant2

                                    I mean that it works as it is intended. I turn the ignition key to on, power checks, and the kill switch is set to "run" I guess (I think it is pressed from the top to the bottom), anyway it is working as it is written on it. I believe this is not an electrical issue anymore, my plug is just not soaking in fuel and oil as it should despite the (I think) big compression. Tomorrow I will also have a friend to come over and we will check the exact PSI compression, what should be a correct value? Above 100, with full open throttle?

                                    NINJAN Offline
                                    NINJAN Offline
                                    NINJA
                                    wrote on last edited by NINJA
                                    #22

                                    @Lorant2 OK well it's another issue then. You can download the service manual for free from here;

                                    https://www.manualslib.com/manual/1203458/Yamaha-Dt125re-2005.html

                                    And well worth the money is a Haynes manual;

                                    https://www.ebay.co.uk/itm/Haynes-Workshop-Manual-Yamaha-TZR125-DT125R-DT125X-1987-2007-New-Service-Repair/254113315280?hash=item3b2a5579d0:g:Lu4AAOSw5LZcXG04:rk:3:pf:1&frcectupt=true

                                    Both have lots of tips and troubleshooting guides!!! 😉

                                    SEDUCED BY THE DARK SIDE!!!

                                    1 Reply Last reply
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                                    • L Offline
                                      L Offline
                                      Lorant2
                                      wrote on last edited by Lorant2
                                      #23

                                      Some update:

                                      I have removed everything again, reeds are perfect, intake manifold too. Boost bottle was a little loose so I replaced the clamp on it and it is better now, and managed to start the bike with a catch LOL 😄

                                      I put it in 6. , turn off ignition and bumped it a lot with choke on, then put it in 3. and managed to start it and rev it a little till I dropped the gas and it is not starting again. Also it was smoking a lot but it was revving freely and dropped the rpms nicely too like theres no air leak. I will try to further investigate it.

                                      Also I had the air screw open at only 1/4 turns now. It was on 1 turns before and completely closed when I first disassembled it.

                                      NINJAN 1 Reply Last reply
                                      0
                                      • L Lorant2

                                        Some update:

                                        I have removed everything again, reeds are perfect, intake manifold too. Boost bottle was a little loose so I replaced the clamp on it and it is better now, and managed to start the bike with a catch LOL 😄

                                        I put it in 6. , turn off ignition and bumped it a lot with choke on, then put it in 3. and managed to start it and rev it a little till I dropped the gas and it is not starting again. Also it was smoking a lot but it was revving freely and dropped the rpms nicely too like theres no air leak. I will try to further investigate it.

                                        Also I had the air screw open at only 1/4 turns now. It was on 1 turns before and completely closed when I first disassembled it.

                                        NINJAN Offline
                                        NINJAN Offline
                                        NINJA
                                        wrote on last edited by
                                        #24

                                        @Lorant2 Improvements then? The smoke was probably from the excess fuel aka flooding from repeated starts. Try the electric start with no choke if it feels sluggish to start, crank it a 8-10 times then add choke.

                                        SEDUCED BY THE DARK SIDE!!!

                                        1 Reply Last reply
                                        1
                                        • J Offline
                                          J Offline
                                          Jens Eskildsen
                                          wrote on last edited by
                                          #25

                                          As fot cleaning the choke, as I said theres a passageway in the floatbowl, thats often overlooked when cleaning carbs, as people focuse on the main body. Im not talking about the choke plunger and where it mounts in the carb.

                                          Just another thing to exclude

                                          L 1 Reply Last reply
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