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DT125R FORUM

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  4. crank noise

crank noise

Scheduled Pinned Locked Moved Engine
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  • MadGyverM Offline
    MadGyverM Offline
    MadGyver
    wrote on last edited by
    #2

    @erioni123 Hi. It's not ok,it should spin freely and noiseless. You have to check/replace crankshaft bearings and the bottom big end bearing. I would change them all to be in piece of mind.

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

    1 Reply Last reply
    0
    • E erioni123

      hey doing a rebuild now and i have the barrel off and when i spin it by hand it makes a grinding noise is this okay ? i think it should spin without any noise
      https://imgur.com/gallery/PVuO4DT

      S Offline
      S Offline
      SpookDog
      wrote on last edited by
      #3

      @erioni123

      Ditto, definitely not. New main bearings and seals…

      E 1 Reply Last reply
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      • S SpookDog

        @erioni123

        Ditto, definitely not. New main bearings and seals…

        E Offline
        E Offline
        erioni123
        wrote on last edited by
        #4

        @SpookDog i see koyo main bearings the pop up a lot when i search on google are they any good

        S 1 Reply Last reply
        0
        • E erioni123

          @SpookDog i see koyo main bearings the pop up a lot when i search on google are they any good

          S Offline
          S Offline
          SpookDog
          wrote on last edited by SpookDog
          #5

          @erioni123

          They’re the ones to get. There is a type to get though, don’t get the ‘cs’ type (I think!)…

          CRB023

          These are the ones to get I think…

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          • CalumC Offline
            CalumC Offline
            Calum
            wrote on last edited by
            #6

            PJME is your friend. Make sure you get the right clearances as well. C3 IIRC.

            Yamaha DT125R Crankshaft Main Bearing LH

            Yamaha DT125R Crankshaft Main Bearing RH

            I always replace all other gearbox bearings whilst you're there, but that's just me and my OCD.

            Always Originate, Never Pirate!

            E 1 Reply Last reply
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            • CalumC Calum

              PJME is your friend. Make sure you get the right clearances as well. C3 IIRC.

              Yamaha DT125R Crankshaft Main Bearing LH

              Yamaha DT125R Crankshaft Main Bearing RH

              I always replace all other gearbox bearings whilst you're there, but that's just me and my OCD.

              E Offline
              E Offline
              erioni123
              wrote on last edited by
              #7

              @Calum is there any way to split the cases without a case splitter as someone said that you can but i dont think you can

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

                I've never used a case splitter. What is a case splitter?

                Always Originate, Never Pirate!

                E 1 Reply Last reply
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                • CalumC Calum

                  I've never used a case splitter. What is a case splitter?

                  E Offline
                  E Offline
                  erioni123
                  wrote on last edited by
                  #9

                  @Calumhow do i split the case tho, the cank case how do i split it apart to change the bearings

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                  • CalumC Offline
                    CalumC Offline
                    Calum
                    wrote on last edited by
                    #10

                    Undo the bolts, dismantle the clutch/generator and then gently tap the casings apart. I use a rubber mallet.

                    Always Originate, Never Pirate!

                    E 1 Reply Last reply
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                    • CalumC Calum

                      Undo the bolts, dismantle the clutch/generator and then gently tap the casings apart. I use a rubber mallet.

                      E Offline
                      E Offline
                      erioni123
                      wrote on last edited by
                      #11

                      @Calum how do you tap them apart like there is no place to hit it

                      S 1 Reply Last reply
                      0
                      • CalumC Offline
                        CalumC Offline
                        Calum
                        wrote on last edited by Calum
                        #12

                        There is a spot where the starter motor goes. And there is a piece up top near the inlet manifold.

                        It literally only needs a gentle tap.

                        The other good technique is just use the flywheel puller. These can be had on eBay for next to nothing and can even be made from scrap metal. It's well described in the Haynes.

                        Always Originate, Never Pirate!

                        1 Reply Last reply
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                        • E erioni123

                          @Calum how do you tap them apart like there is no place to hit it

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

                          @erioni123

                          I don’t mean to offend.
                          Are you sure you’re up for this? Is this the first engine that you’ve worked on?
                          There are certain tools you need to dismantle the engine. Not to mention the damage you can do trying to remove bearings, even after you’ve successfully dismantled the casing…

                          E 1 Reply Last reply
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                          • S SpookDog

                            @erioni123

                            I don’t mean to offend.
                            Are you sure you’re up for this? Is this the first engine that you’ve worked on?
                            There are certain tools you need to dismantle the engine. Not to mention the damage you can do trying to remove bearings, even after you’ve successfully dismantled the casing…

                            E Offline
                            E Offline
                            erioni123
                            wrote on last edited by
                            #14

                            @SpookDog its my first time splitting cases but im not sure if i will do it myself maybe i'll have someone do the rest of the work just to be safer, but i saw that people use case spliters its a tool made for spliting them

                            S 1 Reply Last reply
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                            • E erioni123

                              @SpookDog its my first time splitting cases but im not sure if i will do it myself maybe i'll have someone do the rest of the work just to be safer, but i saw that people use case spliters its a tool made for spliting them

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

                              @erioni123

                              Like Callum said, use a flywheel puller to push the crank in and separate the cases. DO NOT use a screwdriver or chisel, please!…

                              A rubber mallet is usually enough for me…

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