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    Took head off after breakdown

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    • Zrako
      Zrako last edited by Zrako

      Well , finally opened the engine , this piston did 400 miles , find out that 300ml trans oil left , bit in coolant and lot in crank case. Sparkplug was badly fouled , similar to the piston on the pic . I was probably burning it as well but didnt smell or didnt seen any bad smoke... Trying to figure out what actually happened.

      0_1496072230365_20170529_162936.jpg

      0_1496072241346_20170529_162942.jpg

      0_1496072249339_20170529_162950.jpg

      0_1496072268856_20170529_163006.jpg

      0_1496072279447_20170529_163446.jpg

      0_1496072286791_20170529_163515.jpg

      Aaand this 😓
      0_1496073087185_20170529_165023.jpg

      1 Reply Last reply Reply Quote 1
      • Zrako
        Zrako last edited by

        Any idea what I did wrong?

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

          Did you replace the crankshaft seal?

          If so did you have it on the right way round?

          Zrako 1 Reply Last reply Reply Quote 0
          • Zrako
            Zrako last edited by

            Which seal is it?

            1 Reply Last reply Reply Quote 0
            • L
              louis last edited by

              The piston looks like you went to lean.
              Google "lean piston" and you see many like them.

              1 Reply Last reply Reply Quote 1
              • Zrako
                Zrako @Calum last edited by

                @Calum googled it , no I didnt. Used the old ones.

                Calum 1 Reply Last reply Reply Quote 0
                • Calum
                  Calum @Zrako last edited by

                  @Zrako It looks incredibly oily.

                  I thought you said you rebuilt the engine sorry?

                  It's hard to say what the problem is, although if it's lost gearbox oil, and oil was in the crank case and the piston is filthy, then it could have been the crank seal.

                  Zrako 1 Reply Last reply Reply Quote 0
                  • Zrako
                    Zrako @Calum last edited by

                    @Calum yes I did rebuilt it like 3 months ago I think. Gonna get the seals and replace them soon . I have a spare mitaka piston , but both looks slightly different than the one before. Will post a pics tomorrow...

                    Calum 1 Reply Last reply Reply Quote 0
                    • Calum
                      Calum @Zrako last edited by

                      @Zrako So what did you rebuild exactly? If you used old components then that might be the problem. I think they're only a couple of quid and for the sake of them I'd just replace them.

                      1 Reply Last reply Reply Quote 0
                      • Zrako
                        Zrako last edited by Zrako

                        @Calum My bottom end bearing gone before so I got the new conrod and piston , got the crank rebuilt , used new gaskets and fasteners, new clutch plates and springs,installed kickstart ,new oil and waterless coolant... same big one pipe as I had before but in good condition... Thats it basically.

                        Calum 1 Reply Last reply Reply Quote 0
                        • Calum
                          Calum @Zrako last edited by

                          @Zrako what! And you didn't replace the crank seals? For the few quid and two seconds it takes?

                          If the big end bearong went then it's likely that it took the seals with it. I would replace both of, which means splitting the cases unfortunately.

                          Zrako 1 Reply Last reply Reply Quote 0
                          • Zrako
                            Zrako @Calum last edited by

                            @Calum well ,Im failed again then... never did it before but will remeber that for future. Ordered them now. Thanks for help

                            Calum 1 Reply Last reply Reply Quote 0
                            • Calum
                              Calum @Zrako last edited by

                              @Zrako Let's hope this was the failure point.

                              Zrako 1 Reply Last reply Reply Quote 1
                              • Zrako
                                Zrako @Calum last edited by

                                @Calum thinking about build it up again and give it to someone to check and tune it properly as Im lost confidence haha .

                                Calum 1 Reply Last reply Reply Quote 0
                                • Calum
                                  Calum @Zrako last edited by

                                  @Zrako Not really mate. It's so simple and we are here to help.

                                  Literally it's the crank seals. Yoy gotta imagine that when the bearings went they would have gone for the softest part of the engine, whih is the seals.

                                  Zrako 1 Reply Last reply Reply Quote 0
                                  • Zrako
                                    Zrako @Calum last edited by

                                    @Calum yeah , didnt thought about it as I think I checked them , silly mistake. Do you think I will need a new head gasket ? Im did the light skim as you made the tutorial for it , dont know how to identify if the head gasket is bad or reuseable...

                                    Calum 1 Reply Last reply Reply Quote 0
                                    • Calum
                                      Calum @Zrako last edited by

                                      @Zrako Head Gaskets are not reusable.

                                      My advice, don't take the head off, but I'm guessing it's too late for that now.

                                      Athena head gasket is only a tenner.

                                      1 Reply Last reply Reply Quote 1
                                      • Zrako
                                        Zrako last edited by

                                        Well , here we go again . 2nd rebuild . Now with new crank bearings and seals 🙄 , new piston and rings , new - used clutch , removed kickstart and got new used stay for the sprag clutch and installed starter motor, fresh gear oil.

                                        https://youtu.be/b2MZ359Ag3g

                                        Here is what it sounds like . First start was surprisingly smooth ,was idling bit higher so turned it down and bled autolube . Feel strange as it was maybe too good to be true lol .
                                        Let me know what you think about the sound. Havent jump on it yet btw.

                                        NINJA 1 Reply Last reply Reply Quote 2
                                        • NINJA
                                          NINJA @Zrako last edited by

                                          @Zrako Sounds like a 4 stroke with the airbox lid off. LOL

                                          Great job tho!!! 👍

                                          1 Reply Last reply Reply Quote 1
                                          • Zrako
                                            Zrako last edited by

                                            0_1500242402424_20170716_225845.jpg

                                            0_1500242412618_20170716_225908.jpg

                                            Well , brand new iridium br9eix after like 30 minutes idling. First 5 minutes was bleeding oil pump. Doesnt smoke too much . 🤕

                                            Calum 1 Reply Last reply Reply Quote 0
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