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    Engine Rebuilt, Now wont start, and makes horrible dump valve sound when turned off

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    • J
      jamesdowning last edited by

      Hi, looking for some advice...

      I rebuilt my bottom end and have put it back in the frame, connected electrics and put coolant in the radiator. I just tried kicking it over (about 10 kicks) and nothing happened. I then turned the on/off switch from on to off, and all of a sudden the bike released a load of pressure, it sounded like a dump valve. Did it once more (only a couple of kicks) to see if it was a fluke, and it happened again. To add insult to injury my coolant is now drip leaking from the crank sealant. Has anyone got any idea what might cause thise to happen or how to rectify it? Could wiring it up wrong have caused this?

      Thanks
      James

      1 Reply Last reply Reply Quote 0
      • F
        finnerz89 last edited by

        Did you have the rad cap off when kicking it over?

        1 Reply Last reply Reply Quote 0
        • J
          jamesdowning last edited by

          No! Which i then realised, so when i tried it again i did have it off. Although that might have caused the leak initially i still dont think it explain the dumping noise and lack of ignition? Any ideas? Thanks for your help.

          NINJA 1 Reply Last reply Reply Quote 0
          • NINJA
            NINJA @jamesdowning last edited by

            @jamesdowning Always keep it on dude, as the cooling system needs to be pressurised.

            F 1 Reply Last reply Reply Quote 0
            • F
              finnerz89 @NINJA last edited by

              @NINJA if you've put fresh coolant in an empty system you need to bleed it though

              J 1 Reply Last reply Reply Quote 1
              • J
                jamesdowning @finnerz89 last edited by

                @finnerz89 yeah, but it shouldnt stop the engine starting should it? So confused now haha.

                1 Reply Last reply Reply Quote 0
                • J
                  jamesdowning last edited by

                  The main concern is that it wont turn over, and that pressure (pressure that i dont think should be there?) is dumped when the on/off switch is turned to off.

                  Calum NINJA 2 Replies Last reply Reply Quote 0
                  • Calum
                    Calum @jamesdowning last edited by

                    @jamesdowning You sure it's not just the powervalve mate.

                    Turning the ignition on and off isn't going to dump any pressure.

                    J 1 Reply Last reply Reply Quote 0
                    • NINJA
                      NINJA @jamesdowning last edited by NINJA

                      @jamesdowning It sounds like something is not connected correctly or you've damaged a seal when bolting everything back up? If the system is not pressurised and air is trapped in there, then that would most likely give you the dumping sound which you refer to? As @finnerz89 said you need to bleed the system and put new fluid in without adding air. Using a plastic syringe which can be easily bought off ebay is ideal for this, as well as being perfect for bleeding brakes too. If you can connect it at the bottom and pump fluid up-hill, leaving the rad cap off, then using the plunger in the syringe pull it back and forth to pump fluid in and out, that will blow air out of your system.

                      D J 2 Replies Last reply Reply Quote 0
                      • D
                        DTR+NSR @NINJA last edited by

                        I'd say the pressure noise would be the plug igniting fuel in cylinder, noticed on my dtr it would produce a weak spark couple times after kill switch was set to off.

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

                          @Calum my dtr doesnt have a servo style powervalve, it has the old style where you set it how you want it. Therefore dont think the ignition would move it. I agree the switch shouldnt have any effect on the dump noise but it deffo did. Bit weird, hence why i think i might have wired it up wrong somehow

                          Calum 1 Reply Last reply Reply Quote 0
                          • J
                            jamesdowning @NINJA last edited by

                            @NINJA Thanks fir the tip mate, yeah think the seal is now damaged, but think the damage was caused as a result of the sudden high pressure build up, as apposed to me damaging it on assembly. Cheers for the pointers

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

                              @jamesdowning It's nothing to do with Age about having a powervalve on a DTR.

                              Since the LC's were fitted with YPVS Servos.

                              The earlier models were about proving you had the appropriate license to have one. The later models were restricted in other ways, but kept the servo.

                              J 1 Reply Last reply Reply Quote 0
                              • J
                                jamesdowning @DTR+NSR last edited by

                                @DTR-NSR ok, definitely possible and sounds like it could be the case! I'll have a look

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

                                  @Calum So a 97 dtr can be fitted with a servo? Bit confused mate haha

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

                                    @jamesdowning Yeah, the older models ran an independent 3 wire servo. Unlike the 5 wire ones on the later models.

                                    Having a servo is well worth it. All benefits no cons.

                                    J 1 Reply Last reply Reply Quote 0
                                    • D
                                      DTR+NSR last edited by

                                      I'd check you've got a healthy spark kicking it over with kill switch set to run. Does sound electrical with it being connected with touching switch.

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

                                        @Calum I'll look into it once this bloody bike runs! Cheers mate

                                        1 Reply Last reply Reply Quote 0
                                        • J
                                          jamesdowning @DTR+NSR last edited by

                                          @DTR-NSR thanks! checking for a spark will be next on the cards! If theres no spark does anyone know the most likely causes? Or is that a stupid question? Guess theres plenty of reasons for not getting a spark?

                                          NINJA 1 Reply Last reply Reply Quote 0
                                          • Mightyman
                                            Mightyman Global Moderator last edited by Mightyman

                                            I imagine the sound you heard was like the first few seconds of this vid?

                                            https://youtu.be/-x3hPW08ZqA

                                            In that bike's case it was the bottom end on the way out and there was play in the conrod but obviously shouldn't be the case with your bike.

                                            Could be compression related though I guess.. Did you get your cylinder checked for correct sized piston?

                                            1 Reply Last reply Reply Quote 0
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