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DT125R FORUM

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  4. So Close!...

So Close!...

Scheduled Pinned Locked Moved DTR
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  • S SpookDog

    @mhbikesnbits

    Not a stupid question. Yep, gasket is UP, not 9U 🙂

    I actually thought that the coolant I was using was softening the black gasket coating and allowing leaks, but I’ve tried just pure H2o with no change...

    Only difference was that this time the gasket failed at the bottom, barrel side. It has always failed at the top between the gasket and the head before...

    I’m gonna try the studs hand tight this time as well. Just so everything can expand & contract evenly...

    I’m also thinking of contacting an excorcist ☠️

    CalumC Offline
    CalumC Offline
    Calum
    wrote on last edited by
    #155

    @SpookDog This is fucking mental!!!!!!

    Seriously what the hell is going on? Where abouts do you live? I'm half tempted to drive round and do this myself! There is no way you should be having this much trouble with the head gasket. How have you not given up by now!

    I don't understand 😮

    There HAS to be some underlying issue here we aren't seeing.

    Maybe there is a crack in the bottom end, where the coolant chambers meet. This would cause pressure into the engine and potentially blow a gasket. My only problem with that theory is that it'll induce black two stroke into the coolant system.

    Always Originate, Never Pirate!

    S 1 Reply Last reply
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    • CalumC Calum

      @SpookDog This is fucking mental!!!!!!

      Seriously what the hell is going on? Where abouts do you live? I'm half tempted to drive round and do this myself! There is no way you should be having this much trouble with the head gasket. How have you not given up by now!

      I don't understand 😮

      There HAS to be some underlying issue here we aren't seeing.

      Maybe there is a crack in the bottom end, where the coolant chambers meet. This would cause pressure into the engine and potentially blow a gasket. My only problem with that theory is that it'll induce black two stroke into the coolant system.

      S Offline
      S Offline
      SpookDog
      wrote on last edited by
      #156

      @Calum

      Bud, it is so beyond being real, you couldn’t make this shit up! I’m just so stubborn I won’t give up. I just wish I could believe I’m doing something obviously wrong. Or afford to take it to a shop and let them keep mending it if it goes again!...

      Next time I’ll take detailed pics and post all that I’m doing. It’s just so fuckin exhausting!! 😐 I’ll get there eventually tho...

      CalumC 1 Reply Last reply
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      • S SpookDog

        @Calum

        Bud, it is so beyond being real, you couldn’t make this shit up! I’m just so stubborn I won’t give up. I just wish I could believe I’m doing something obviously wrong. Or afford to take it to a shop and let them keep mending it if it goes again!...

        Next time I’ll take detailed pics and post all that I’m doing. It’s just so fuckin exhausting!! 😐 I’ll get there eventually tho...

        CalumC Offline
        CalumC Offline
        Calum
        wrote on last edited by
        #157

        @SpookDog I'd seriously be contemplating that engine. Something must be amiss.

        Always Originate, Never Pirate!

        S 1 Reply Last reply
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        • CalumC Calum

          @SpookDog I'd seriously be contemplating that engine. Something must be amiss.

          S Offline
          S Offline
          SpookDog
          wrote on last edited by
          #158

          @Calum

          Yeah. I just can’t imagine how the bottom end could affect the head seal. I thought it might be the budget price eBay Athena gaskets at one point. Changed to Vertex with same results. I’ve tried 3 different barrel & head combinations. I’m the only constant factor 😟

          CalumC 1 Reply Last reply
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          • S SpookDog

            @Calum

            Yeah. I just can’t imagine how the bottom end could affect the head seal. I thought it might be the budget price eBay Athena gaskets at one point. Changed to Vertex with same results. I’ve tried 3 different barrel & head combinations. I’m the only constant factor 😟

            CalumC Offline
            CalumC Offline
            Calum
            wrote on last edited by
            #159

            @SpookDog That's why I'm thinking it's a bottom end issue. As it's not the head/barrel so the only thing left is either, you or the bottom end. Given how simple the job is, I'm betting on the bottom end.

            Always Originate, Never Pirate!

            S 1 Reply Last reply
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            • CalumC Calum

              @SpookDog That's why I'm thinking it's a bottom end issue. As it's not the head/barrel so the only thing left is either, you or the bottom end. Given how simple the job is, I'm betting on the bottom end.

              S Offline
              S Offline
              SpookDog
              wrote on last edited by
              #160

              @Calum

              I even thought it was something to do with the engine mounts, especially the head one putting too much stress on it...

              Then again I reach for just about anything to make sense of the ‘situation’ 🙂

              I put it back together with a new Vertex gasket and yet another, different, 3mb barrel, piston & 3mb head (£50, thanks eBay!!) Hoping this time it’ll last longer than 3~6 weeks! 🤞 ...

              Did a 70 mile trip to shake it down with no hiccups 😜 ...

              HOTSHOT IIIH 1 Reply Last reply
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              • S SpookDog

                @Calum

                I even thought it was something to do with the engine mounts, especially the head one putting too much stress on it...

                Then again I reach for just about anything to make sense of the ‘situation’ 🙂

                I put it back together with a new Vertex gasket and yet another, different, 3mb barrel, piston & 3mb head (£50, thanks eBay!!) Hoping this time it’ll last longer than 3~6 weeks! 🤞 ...

                Did a 70 mile trip to shake it down with no hiccups 😜 ...

                HOTSHOT IIIH Offline
                HOTSHOT IIIH Offline
                HOTSHOT III
                wrote on last edited by
                #161

                @SpookDog Just been reading about your headgasket situation.

                On another thread you commented that you've blocked off your carb warmer circuit using allen bolts and copper washers; potentially this means your cooling system is no longer self-bleeding when you refill the coolant (the stock thermostat has a small bleed hole but it's tiny, <1mm so there's no guarantee this isn't blocked).

                If you have an air pocket right at the top of the head, the coolant may not be pressurising which will lower its boiling point and lead to overheating (and an air pocket will itself lead to a hot spot as there's less coolant there to carry away the excess heat). Possibly increasing the likelihood of your headgasket(s) to fail.

                Try refitting the carb warmer circuit banjos so you can disconnect the hose at the thermostat housing until coolant free of air bubbles emerges when refilling the system (this is how Yamaha and Haynes recommend bleeding the cooling system). If you don't want the carb warmer circuit you can just run a hose straight from one banjo to the other so access to the carb isn't affected.

                Considering how much trouble you've had with ebay gaskets etc., I'd also invest in a genuine Yamaha gasket and maybe a new thermostat (or at least remove yours and test it),

                S 2 Replies Last reply
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                • HOTSHOT IIIH HOTSHOT III

                  @SpookDog Just been reading about your headgasket situation.

                  On another thread you commented that you've blocked off your carb warmer circuit using allen bolts and copper washers; potentially this means your cooling system is no longer self-bleeding when you refill the coolant (the stock thermostat has a small bleed hole but it's tiny, <1mm so there's no guarantee this isn't blocked).

                  If you have an air pocket right at the top of the head, the coolant may not be pressurising which will lower its boiling point and lead to overheating (and an air pocket will itself lead to a hot spot as there's less coolant there to carry away the excess heat). Possibly increasing the likelihood of your headgasket(s) to fail.

                  Try refitting the carb warmer circuit banjos so you can disconnect the hose at the thermostat housing until coolant free of air bubbles emerges when refilling the system (this is how Yamaha and Haynes recommend bleeding the cooling system). If you don't want the carb warmer circuit you can just run a hose straight from one banjo to the other so access to the carb isn't affected.

                  Considering how much trouble you've had with ebay gaskets etc., I'd also invest in a genuine Yamaha gasket and maybe a new thermostat (or at least remove yours and test it),

                  S Offline
                  S Offline
                  SpookDog
                  wrote on last edited by
                  #162

                  2 weeks and still have a functioning head gasket and cooling system 😁 I’m not counting my albatross’s yet but it’s looking good...

                  1 Reply Last reply
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                  • HOTSHOT IIIH HOTSHOT III

                    @SpookDog Just been reading about your headgasket situation.

                    On another thread you commented that you've blocked off your carb warmer circuit using allen bolts and copper washers; potentially this means your cooling system is no longer self-bleeding when you refill the coolant (the stock thermostat has a small bleed hole but it's tiny, <1mm so there's no guarantee this isn't blocked).

                    If you have an air pocket right at the top of the head, the coolant may not be pressurising which will lower its boiling point and lead to overheating (and an air pocket will itself lead to a hot spot as there's less coolant there to carry away the excess heat). Possibly increasing the likelihood of your headgasket(s) to fail.

                    Try refitting the carb warmer circuit banjos so you can disconnect the hose at the thermostat housing until coolant free of air bubbles emerges when refilling the system (this is how Yamaha and Haynes recommend bleeding the cooling system). If you don't want the carb warmer circuit you can just run a hose straight from one banjo to the other so access to the carb isn't affected.

                    Considering how much trouble you've had with ebay gaskets etc., I'd also invest in a genuine Yamaha gasket and maybe a new thermostat (or at least remove yours and test it),

                    S Offline
                    S Offline
                    SpookDog
                    wrote on last edited by SpookDog
                    #163

                    @HOTSHOT-III

                    Cheers for the input. I’ve tried various new and older but tested thermostats. I’ve tried different head nuts & washers. Studs locktighted and not, finger tight and cinched up tight. Tried the head to frame mount tight and ‘not tight’ thinking there may be too much stress on the head through the mount. I think I’m on my fourth different head & barrel combo. Using pure water at the moment, also changed my 2stroke oil thinking that there may be some kind of reaction between it and the gasket covering...

                    Gasket has always leaks at a different point. Always between the gasket upper surface and the head apart from the one time last time when it leaked both sides of the gasket...

                    Any idea or input is appreciated greatly, but yes I always put the gasket UP the proper way 😜 ...

                    CalumC 1 Reply Last reply
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                    • S SpookDog

                      @HOTSHOT-III

                      Cheers for the input. I’ve tried various new and older but tested thermostats. I’ve tried different head nuts & washers. Studs locktighted and not, finger tight and cinched up tight. Tried the head to frame mount tight and ‘not tight’ thinking there may be too much stress on the head through the mount. I think I’m on my fourth different head & barrel combo. Using pure water at the moment, also changed my 2stroke oil thinking that there may be some kind of reaction between it and the gasket covering...

                      Gasket has always leaks at a different point. Always between the gasket upper surface and the head apart from the one time last time when it leaked both sides of the gasket...

                      Any idea or input is appreciated greatly, but yes I always put the gasket UP the proper way 😜 ...

                      CalumC Offline
                      CalumC Offline
                      Calum
                      wrote on last edited by
                      #164

                      @SpookDog I am at a total loss as to why you're having so many problems.

                      Next thing we need to check is the compression. If you're running like million PSI compression then that would explain something.

                      I mean, these bikes were exported globally so you really shouldn't be having this much issue. They are also very basic and you really have to be doing something wrong to be having this much trouble.

                      Always Originate, Never Pirate!

                      S 1 Reply Last reply
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                      • CalumC Calum

                        @SpookDog I am at a total loss as to why you're having so many problems.

                        Next thing we need to check is the compression. If you're running like million PSI compression then that would explain something.

                        I mean, these bikes were exported globally so you really shouldn't be having this much issue. They are also very basic and you really have to be doing something wrong to be having this much trouble.

                        S Offline
                        S Offline
                        SpookDog
                        wrote on last edited by SpookDog
                        #165

                        @Calum

                        I’m hoping that it’s good to go this time. I’ve ran 3bn and different 3mb& 3mb-p heads. Nothing radical 😐 ...

                        The thing is I been doubting myself for a while but I really can’t see anything wrong with my method...
                        If it fails again I’m gonna do a pic by pic slideshow of my methodology to see if anyone can point out anything obvious I’m missing...

                        S CalumC 2 Replies Last reply
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                        • S SpookDog

                          @Calum

                          I’m hoping that it’s good to go this time. I’ve ran 3bn and different 3mb& 3mb-p heads. Nothing radical 😐 ...

                          The thing is I been doubting myself for a while but I really can’t see anything wrong with my method...
                          If it fails again I’m gonna do a pic by pic slideshow of my methodology to see if anyone can point out anything obvious I’m missing...

                          S Offline
                          S Offline
                          SpookDog
                          wrote on last edited by
                          #166

                          My only real doubt is my lapping technique for clean old gasket crap off and prepping the barrel top and head mating surfaces. I’m gonna get a new peice of plate glass and new wet n dry for future endeavours...

                          I might just get them skimmed/finished by PJME as well. I have a barrel that needs a new rebore and they were the best finish I’ve ever seen on the bore...

                          I’ll get there sometime soon. The bike is running better than it ever has before since I got the carb jetted proper. I just need to fit my new 3.50 rear tire and lower the gearing so it gets into the power band in 5th & 6th easier...

                          1 Reply Last reply
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                          • S SpookDog

                            @Calum

                            I’m hoping that it’s good to go this time. I’ve ran 3bn and different 3mb& 3mb-p heads. Nothing radical 😐 ...

                            The thing is I been doubting myself for a while but I really can’t see anything wrong with my method...
                            If it fails again I’m gonna do a pic by pic slideshow of my methodology to see if anyone can point out anything obvious I’m missing...

                            CalumC Offline
                            CalumC Offline
                            Calum
                            wrote on last edited by
                            #167

                            @SpookDog What I mean is, if you're running a super thin base gasket, lapped the head a million times + lord knows what someone else did in its life, it could be running super high compression. You've somehow magically managed not to blow the engine up through detonation, but instead are blowing the head gasket...I am really clutching at straws here though.

                            Always Originate, Never Pirate!

                            S 1 Reply Last reply
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                            • CalumC Calum

                              @SpookDog What I mean is, if you're running a super thin base gasket, lapped the head a million times + lord knows what someone else did in its life, it could be running super high compression. You've somehow magically managed not to blow the engine up through detonation, but instead are blowing the head gasket...I am really clutching at straws here though.

                              S Offline
                              S Offline
                              SpookDog
                              wrote on last edited by
                              #168

                              @Calum

                              Bud, I know! But I’ve used so many different head & barrel combinations. It feels more like a witches curse than anything else 👻☠️

                              I’m still getting new possible factors to mind. I will work it out eventually...

                              markus.wM 1 Reply Last reply
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                              • S SpookDog

                                @Calum

                                Bud, I know! But I’ve used so many different head & barrel combinations. It feels more like a witches curse than anything else 👻☠️

                                I’m still getting new possible factors to mind. I will work it out eventually...

                                markus.wM Offline
                                markus.wM Offline
                                markus.w
                                wrote on last edited by
                                #169

                                @SpookDog that's a good point bud. Have you upset any witches in the past? I know I certainly have and it would explain a lot of my problems.

                                S 1 Reply Last reply
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                                • markus.wM markus.w

                                  @SpookDog that's a good point bud. Have you upset any witches in the past? I know I certainly have and it would explain a lot of my problems.

                                  S Offline
                                  S Offline
                                  SpookDog
                                  wrote on last edited by
                                  #170

                                  @markus-w

                                  I can’t say I’ve upset them per se, but they have been pissy at me for sure. I think that they get jealous of your life and then try and drag you down to their level of hell...
                                  There are some messed up creatures out there!! ☠️

                                  T 1 Reply Last reply
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                                  • S SpookDog

                                    @markus-w

                                    I can’t say I’ve upset them per se, but they have been pissy at me for sure. I think that they get jealous of your life and then try and drag you down to their level of hell...
                                    There are some messed up creatures out there!! ☠️

                                    T Offline
                                    T Offline
                                    theportingmaster
                                    wrote on last edited by
                                    #171

                                    @SpookDog Crazy your gasket problems as done loads of engines and every head gasket from cheap white ones in those cheapo full gasket sets to athena gaskets and never had a problem. On barrels always use blowtorch on studs and 40 years working on 2 stroke engines and never snapped a stud yet. Remove studs then piece of glass with 240 wet & dry on barrel and head and 100% flat, I use my cooker hob as it glass really strong and it
                                    doesn,t move about, just do mine when the wife is out.lol

                                    S 1 Reply Last reply
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                                    • T theportingmaster

                                      @SpookDog Crazy your gasket problems as done loads of engines and every head gasket from cheap white ones in those cheapo full gasket sets to athena gaskets and never had a problem. On barrels always use blowtorch on studs and 40 years working on 2 stroke engines and never snapped a stud yet. Remove studs then piece of glass with 240 wet & dry on barrel and head and 100% flat, I use my cooker hob as it glass really strong and it
                                      doesn,t move about, just do mine when the wife is out.lol

                                      S Offline
                                      S Offline
                                      SpookDog
                                      wrote on last edited by
                                      #172

                                      @theportingmaster

                                      That’s the stuff! Old mirrors can be good as well 🙂

                                      I always use heat for stud removal as well. The only time I didn’t I snapped a stud, it had only been in for 6 weeks and not even tight! In hindsight it was too new and shiny (came with a head and barrel I brought) and didn’t have the dimple on the top. Was a cheap fleabay copy I think...

                                      I’ll have to try 240 drift. I can’t remember what I used before. A nice even Matt finish and a check with a steel rule is my usual MO. Head and barrel. The barrel base is more awkward but I use a square glass drinks coaster...

                                      My latest iteration is still hold up. It’s been nearly a 1000 miles now 🤞 ...

                                      S 1 Reply Last reply
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                                      • S SpookDog

                                        @theportingmaster

                                        That’s the stuff! Old mirrors can be good as well 🙂

                                        I always use heat for stud removal as well. The only time I didn’t I snapped a stud, it had only been in for 6 weeks and not even tight! In hindsight it was too new and shiny (came with a head and barrel I brought) and didn’t have the dimple on the top. Was a cheap fleabay copy I think...

                                        I’ll have to try 240 drift. I can’t remember what I used before. A nice even Matt finish and a check with a steel rule is my usual MO. Head and barrel. The barrel base is more awkward but I use a square glass drinks coaster...

                                        My latest iteration is still hold up. It’s been nearly a 1000 miles now 🤞 ...

                                        S Offline
                                        S Offline
                                        SpookDog
                                        wrote on last edited by
                                        #173

                                        Head gasket lasted 18 days 😐

                                        CalumC markus.wM 2 Replies Last reply
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                                        • S SpookDog

                                          Head gasket lasted 18 days 😐

                                          CalumC Offline
                                          CalumC Offline
                                          Calum
                                          wrote on last edited by
                                          #174

                                          @SpookDog I think you're wasting your time now, something isn't right with that engine. There is an underlying issue here.

                                          Always Originate, Never Pirate!

                                          S 1 Reply Last reply
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