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    Really bad vibrations

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    • Haako Smith
      Haako Smith last edited by

      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?

      james 1 Reply Last reply Reply Quote 0
      • Calum
        Calum last edited by

        The basket is fixed onto primary output shaft. I.E. it should have no up or down play.

        How did you inspect the balancer shaft.

        I wouldn't expect this to move, once it's timed up and the cogs are fitted into place there should be no movement whatsoever.

        1 Reply Last reply Reply Quote 1
        • Haako Smith
          Haako Smith last edited by

          I looked at the balancing shaft and the crank, and the 2 dots line up, I know that is fine.
          But the cog itself has play from the basket if you get it xD
          I’ll trie to post some pictures.

          1 Reply Last reply Reply Quote 0
          • S
            SpookDog last edited by

            The clutch basket is rubber bushes inside (that’s why there are hammered rivets on the back of the basket). It stops the clutch snatching. They all have a certain amount of give.
            The cog itself is tight with the crank/balancer.

            1 Reply Last reply Reply Quote 0
            • S
              SpookDog last edited by

              When you say mad vibrations, can you elaborate? Is it when the bike is stood still and just revving up? Or moving?

              I’ve had a main/crank bearing cage fail on a 4stroke. It let the ball bearings ‘slap around’ out of balance. It really threw the revving up out of whack...

              1 Reply Last reply Reply Quote 0
              • Haako Smith
                Haako Smith last edited by

                Sorry for the late respond.
                It is vibrating even when I stands still I neutral. Could it be that’s the bushing are the cause? Or maybe something else?

                1 Reply Last reply Reply Quote 0
                • S
                  SpookDog last edited by

                  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 Reply Quote 0
                  • Calum
                    Calum last edited by

                    None of the engine mounts are loose are they?

                    Haako Smith 1 Reply Last reply Reply Quote 1
                    • Haako Smith
                      Haako Smith last edited by

                      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 Reply Quote 0
                      • Haako Smith
                        Haako Smith @Calum last edited by

                        @Calum
                        No, all are tight and good!

                        1 Reply Last reply Reply Quote 0
                        • S
                          SpookDog @Haako Smith last edited by 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 Smith 1 Reply Last reply Reply Quote 0
                          • Haako Smith
                            Haako Smith @SpookDog last edited by

                            @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 Reply Quote 0
                            • S
                              SpookDog @Haako Smith last edited by 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 Smith 1 Reply Last reply Reply Quote 0
                              • Haako Smith
                                Haako Smith @SpookDog last edited by

                                @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 Reply Quote 0
                                • S
                                  SpookDog @Haako Smith last edited by

                                  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 Smith 1 Reply Last reply Reply Quote 0
                                  • james
                                    james @Haako Smith last edited by

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

                                      This post is deleted!
                                      1 Reply Last reply Reply Quote 0
                                      • Haako Smith
                                        Haako Smith @james last edited by

                                        @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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