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DT125R FORUM

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  4. Really bad vibrations

Really bad vibrations

Scheduled Pinned Locked Moved Engine
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  • S Offline
    S Offline
    SpookDog
    wrote on last edited by
    #7

    If it’s doing it stood still, I’d suspect the main bearings. Especially if it’s erratic to rev up and down? If the cage disintegrated the ball bearings would group together and throw the balance off. It’s what happened to me...

    You’ve already had the clutch cover/casing off, did you check all the drive nuts were tight? Crank, clutch, balancer shaft, ect...

    1 Reply Last reply
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    • CalumC Offline
      CalumC Offline
      Calum
      wrote on last edited by
      #8

      None of the engine mounts are loose are they?

      Always Originate, Never Pirate!

      Haako SmithH 1 Reply Last reply
      1
      • Haako SmithH Offline
        Haako SmithH Offline
        Haako Smith
        wrote on last edited by
        #9

        Hmm yea, maybe it could be the bearings, although I changed one of them last winter, I know I should have changed both but I only have one 🙂 Yea, all of the nuts were tight and no loose nuts

        S 1 Reply Last reply
        0
        • CalumC Calum

          None of the engine mounts are loose are they?

          Haako SmithH Offline
          Haako SmithH Offline
          Haako Smith
          wrote on last edited by
          #10

          @Calum
          No, all are tight and good!

          1 Reply Last reply
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          • Haako SmithH Haako Smith

            Hmm yea, maybe it could be the bearings, although I changed one of them last winter, I know I should have changed both but I only have one 🙂 Yea, all of the nuts were tight and no loose nuts

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

            @Haako-Smith
            I just re read your first post. It won’t rev up...
            One thing you can try is to turn the engine over by hand. Turn the magneto rotor over, back and forwards, see if it feels ‘crunchy’ at all. Anything but smooth...

            P.S. has the posting format changed? I could only find the ‘button’ I normally use in the first post. I’ve never seen the @whoever reply thing before...

            Haako SmithH 1 Reply Last reply
            0
            • S SpookDog

              @Haako-Smith
              I just re read your first post. It won’t rev up...
              One thing you can try is to turn the engine over by hand. Turn the magneto rotor over, back and forwards, see if it feels ‘crunchy’ at all. Anything but smooth...

              P.S. has the posting format changed? I could only find the ‘button’ I normally use in the first post. I’ve never seen the @whoever reply thing before...

              Haako SmithH Offline
              Haako SmithH Offline
              Haako Smith
              wrote on last edited by
              #12

              @SpookDog
              Hey.
              The I tried to rotate, and it feels like normal. Nothing crunchy or anything. I also tried to swap the clutch basket out with another one I had laying around, which I knew worked when I took It off. I started it up and with no luck, same vibration 😞

              Yea I also saw the @thing haven’t seen it before.

              S 1 Reply Last reply
              0
              • Haako SmithH Haako Smith

                @SpookDog
                Hey.
                The I tried to rotate, and it feels like normal. Nothing crunchy or anything. I also tried to swap the clutch basket out with another one I had laying around, which I knew worked when I took It off. I started it up and with no luck, same vibration 😞

                Yea I also saw the @thing haven’t seen it before.

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

                @Haako-Smith
                dude, if the engine is tight in the frame and you’ve already been clutch deep. You’re going to have to go deeper. It can only be something that’s spinning and out of whack. Which is clutch side (input) gear shaft, balance shaft and crank. There is nothing else. My concern is that if the bearing race has failed, where is the metal? It could only go out round the inner crank case...
                Only other thing I can think of is the rotor woodruff key. Remove the rotor and check the keyway on the shaft. I’ve had these go bad and ruin the key slot/hole, no matter how much I tightened it it wobbled loose. I had to braze a woodruff key into the crank in the end...

                Haako SmithH 1 Reply Last reply
                0
                • S SpookDog

                  @Haako-Smith
                  dude, if the engine is tight in the frame and you’ve already been clutch deep. You’re going to have to go deeper. It can only be something that’s spinning and out of whack. Which is clutch side (input) gear shaft, balance shaft and crank. There is nothing else. My concern is that if the bearing race has failed, where is the metal? It could only go out round the inner crank case...
                  Only other thing I can think of is the rotor woodruff key. Remove the rotor and check the keyway on the shaft. I’ve had these go bad and ruin the key slot/hole, no matter how much I tightened it it wobbled loose. I had to braze a woodruff key into the crank in the end...

                  Haako SmithH Offline
                  Haako SmithH Offline
                  Haako Smith
                  wrote on last edited by
                  #14

                  @SpookDog
                  Hmm yea, I took the woodruff key out, and it looked good. Maybe I just have to start taking it apart🤔

                  S 1 Reply Last reply
                  0
                  • Haako SmithH Haako Smith

                    @SpookDog
                    Hmm yea, I took the woodruff key out, and it looked good. Maybe I just have to start taking it apart🤔

                    S Offline
                    S Offline
                    SpookDog
                    wrote on last edited by
                    #15

                    You can always pop the oil seals before you split the cases. Whatever, you’re gonna have to take off the top end to get a look at the crank. I think surgery is the only option 😐

                    Haako SmithH 1 Reply Last reply
                    0
                    • Haako SmithH Haako Smith

                      When i was riding today, all of a sudden my bike started vibrating like mad. And it seems like it won’t Rev up. I checked the balancing shaft and flywheel, which all seems fine. However the clutch basket has quite a bit of play between the actual cog and the basket. Could this cause mad vibration? Or what else could?

                      jamesJ Offline
                      jamesJ Offline
                      james
                      wrote on last edited by
                      #16

                      @Haako-Smith have a look at the bottom end bearings very easy to mis hap for good wen bad pal just had the same thing 1 of the bottom bearings were shot hope this helps pal

                      Haako SmithH 1 Reply Last reply
                      0
                      • S SpookDog

                        You can always pop the oil seals before you split the cases. Whatever, you’re gonna have to take off the top end to get a look at the crank. I think surgery is the only option 😐

                        Haako SmithH Offline
                        Haako SmithH Offline
                        Haako Smith
                        wrote on last edited by
                        #17
                        This post is deleted!
                        1 Reply Last reply
                        0
                        • jamesJ james

                          @Haako-Smith have a look at the bottom end bearings very easy to mis hap for good wen bad pal just had the same thing 1 of the bottom bearings were shot hope this helps pal

                          Haako SmithH Offline
                          Haako SmithH Offline
                          Haako Smith
                          wrote on last edited by
                          #18

                          @james
                          Thanks for the tips!
                          I have a spare engine that I will swap it with in the meantime.
                          Thanks to everyone who have helped!

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