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    • #4685
      andy pagett
      Participant

      thinking of fitting stainless downpipes to my gt125r , would I need to change the jets on the carbs. Thanks. 

    • #4686
      Scott
      Participant

      If you stick with the standard air filter and end can then no. The stock downpipes are sleeved to half the diameter of the outer pipes and the standard can is too, which would maintain back pressure. But if you’re using a different end can, or have changed the intake system in any way you’ll need to up both jets to next size. You might find you need to fit a baffle too if you’re using an aftermarket can as loss of back pressure means you’ll get zero power at full open throttle.

    • #4688
      ♠️ M77
      Keymaster

      Plus, the Hyosung already runs leaner, so if you think about it, the more gasses LEAVE the bike  (staninless pipes OR aftermarket end can , whichever of these 2) ===> Increase fuel mix, which means uprate the main jets.  A leaner bike is lethal than a slightly rich one , plus hyosungs like to run 1 step richer.  Less drama later on with bike that isn’t going to overheat leaner and glaze up the piston chambers, plugs, and what not.

      Search this forum for “Slide Mod” and “Carb Jet”   which are 2 separate tutorials to help enrich the bike a bit.   If not, i can always paste the links

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