Home Forums TaG Rotax Max 12.5 vs 8.5

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    • #4277
      bruce kapanke
      Participant

      Got a motor with a 12.5 on it. Any problems switching it over to a 8.5? Thanks for any help given.

    • #4357
      Mike Maurini
      Participant

      Hi Bruce,

      Carb can easily be changed over to an 8.5. You will have to run a slightly richer main jet but other than that, you will be good to go. Hope this helps!

      Thanks,

      Mike Maurini

    • #4383
      bruce kapanke
      Participant

      Mike,

      Thanks. Gave me the info I needed.

      bruce

    • #6081
      Joe Morales
      Participant

      I’m wondering why? Why the change? Is it to our advantage or disadvantage?

    • #6094
      Bob Baldwin
      Blocked

      mike : Your comment about switching from a 12 to an 8 in the Carb . Being out of Rotax a few years , I was planning on buying a weather station and getting the proper software to determine the best jetting . Should I be holding out on that or will the Proper software have to be re-configured . ?

    • #6238
      Eric Alexander
      Participant

      Bob, most all jetting software has a means of calibrating the software a small percentage for your specific carb/engine combo.  So in the beginning you need to experiment a wee bit and dial the software in.  But then it becomes pretty much enter the weather data and go with few exceptions. 

      None of the software I’m aware of have the venturi as a spec.  Most all do have float weight/idle jet & emulsion tube size/needle type/spark plug/and float arm height.

    • #6278
      Nick Weil
      Participant

      Bob,

      When are you getting back into a kart!?

    • #6281
      Bob Baldwin
      Blocked

      nick : for the Grandson if I can put the $$$ together 

      Slim pickings for Rotax here in the midwest . Nearest about a 7 hour drive one way Michiana

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