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    DEP vs RomeuHenriques

    Exhaust
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    • P
      PJT95 last edited by

      Hi all,

      I've just found a small hole on my DEP pipe where rust has began to form on one of the welds - as some point I am going to be replacing it/selling it to a friend.

      I've been looking at the RomeuHenriques exhausts that wrap around the frame rather than being underslung. Has anybody owned one of these? If so, how do they handle the weather over time? Did you see an increase of performance over your previous exhaust?

      With a small hole developing on my current DEP exhaust, would this affect the performance of the bike? The hole is where the pipe meets the cylinder so I'm guessing it would be losing a small amount of back pressure..

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      • F
        finnerz89 last edited by

        The more expensive pipes he makes are stainless so they would definitely last longer than any other aftermarket pipe out there.

        With the hole being where it is you could be running lean, but if it's only small then it probably won't make a difference

        Current bikes:
        DT125X '07
        Street Triple R '11
        Aprilia ETV1000 '02

        Previous:
        DR650RSE '96
        FJ1200 '92

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        • Calum
          Calum last edited by

          A hole in a two stroke pipe is going to have adverse effects, small or big.

          Always Originate, Never Pirate!

          1 Reply Last reply Reply Quote 0
          • P
            PJT95 last edited by

            Why would a hole cause the bike to run lean? What causes this?

            I thought that the pressure in the exhaust is higher than the atmosphere around it so air wouldn't be flowing back through the hole in to the cylinder right?

            Correct me if I'm wrong I'm just trying to get a better understanding of what causes the hole could have.

            I'll deffo be getting a replacement exhaust either way I reckon.

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            • Calum
              Calum last edited by

              I've explained this enough times. Plenty of information on the web and I reckon this gif does it justice

              alt text

              If you want to know more, learn about how critical expansion chambers are on two strokes.

              Always Originate, Never Pirate!

              1 Reply Last reply Reply Quote 0
              • P
                PJT95 last edited by

                Cool, thanks for the info @Calum will be having a read later on.

                Calum 1 Reply Last reply Reply Quote 0
                • Calum
                  Calum @PJT95 last edited by

                  @pjt95 Just imagine if there is a hole in your exhaust, that sound wave won't propagate properly. If it does it may push lost fuel and air out the hole, making the next ignition sequence lean. Since you can see the green (fuel/air) charge is usually pushed back into the combustion chamber. Back in the day, there was no such things as expansion chambers, the bikes were jetted accordingly. Yours is jetted to take use of that chamber. No chamber will mean less fuel/air.

                  We're talking minutes amount at this moment in time. And of course it's all hypothetical. But you asked.

                  Always Originate, Never Pirate!

                  declan 1 Reply Last reply Reply Quote 0
                  • P
                    PJT95 last edited by

                    Thanks for the info @Calum , really do appreciate it and have a better understanding now! as for the RomeuHenriques pipes, would you recommend one or would you just buy another DEP?

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

                      @calum as a ball park figure how much could you expect to lose hp wise on my project bike I can put my hand over the exhaust and it will continue to run perfect the leak is that bad now the bike only has 2.9hp I’d expect to lose 2hp so I’ve only just been thinking this is most likely why it has zero torque/power

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                      • Calum
                        Calum @PJT95 last edited by

                        @pjt95 I went with a Romeu pipe myself, because no matter how hard I tried, the DEP insisted on rotting.

                        @declan I'd expect the majority of the power to go if the pipe is that bad. But it all depends on where it is. On a bike with only 2.9 hp, I'd be surprised if the exhaust was even setup properly in the first place. But a decent exhaust on a two stroke, is the difference between naturally aspirated and a turbo engine. The two stroke pipe supercharges the engine. So it's imperative that it's working effectively.

                        Always Originate, Never Pirate!

                        Irongamer727 1 Reply Last reply Reply Quote 1
                        • Irongamer727
                          Irongamer727 @Calum last edited by

                          @calum you think an underslug romeu would work with the 170 kit? Does this Romeu make "regular" pipes as well? Currently have an arrow pipe but it rots fast

                          Calum 1 Reply Last reply Reply Quote 0
                          • Calum
                            Calum @Irongamer727 last edited by

                            @irongamer727 Pipes needto be suited to the engine. But athena is quite common. Ask him, he's pretty knowledgeable.

                            Always Originate, Never Pirate!

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                            • Y
                              Yegor last edited by Yegor

                              @Irongamer727 I have asked him about 170cc kit and the answer was " if you do not tune the Athena kit that exhaust must go good " .

                              Irongamer727 1 Reply Last reply Reply Quote 0
                              • Irongamer727
                                Irongamer727 @Yegor last edited by

                                @yegor the underslug?

                                Calum 1 Reply Last reply Reply Quote 0
                                • Calum
                                  Calum @Irongamer727 last edited by

                                  @irongamer727 Hhmm, it seems like he and I share the same opinion of the Athena kit it would seem.

                                  Always Originate, Never Pirate!

                                  Irongamer727 1 Reply Last reply Reply Quote 0
                                  • O
                                    oldman last edited by

                                    Have just fitted a Romeu exhaust and it is impressive, can't comment on durability or performance as yet. Have a new Dep exhaust that came with the boxed up 88 and was going to get it plated over to try and counter the rot problem. Anyone tried that or any other remedy? Personally would not purchase Dep due to reputation. The seller I bought the bike said he had rejected the first one sent as already had rust on joints.

                                    declan 1 Reply Last reply Reply Quote 0
                                    • declan
                                      declan @oldman last edited by

                                      @oldman so I had a rotten big one I sanded it down and painted it black now it’s like new but obviously you lose the shine but I love it all the same

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                                      • Irongamer727
                                        Irongamer727 @Calum last edited by

                                        @calum which is?

                                        Calum 1 Reply Last reply Reply Quote 0
                                        • Calum
                                          Calum @Irongamer727 last edited by

                                          @irongamer727 My understanding is that the port timings for the 170 Kit was based off the DT200R. As such the ports are 3mm too low. People have shaved 3mm off the head and shimmed it at the base to correct this.

                                          Always Originate, Never Pirate!

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                                          • Calum
                                            Calum last edited by

                                            Here is the link I found when browsing.

                                            http://www.125ccsportsbikes.com/forums/index.php?showtopic=100859

                                            Years ago now mind you.

                                            Always Originate, Never Pirate!

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