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2 stroke carb on a 4 stroke????

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  • 2 stroke carb on a 4 stroke????

    Hey everyone!!
    Is it logical to slap a 2 stroke carb on to a 4 stroke motor??
    will it make a diff in performance??

    I own a Apache RTR.My mechanic is persuading me to replace the stock Mikuni BS26 CV carb with a Mikuni 28mm mechanical carb from a RD350. He claims that it'll provide a straight performance increase. Inspite of the fact that i realize that CV carb technology is as old as 20 years, does it make sense to replace it with another carb thats 20-30 year old in terms of technology??

    My mechanic also claims very confidently that many racing teams, to this day use RD carbs on their race tuned machines, here in south-India!! Is this a valid claim??

    I really need assistance regarding this issue. My ride is not in stock setup but is done up with a CC upgrade, port & polish, bumped up compression and calculated exhaust. now I have to choose from Mikuni BS29 CV from pulsar 200 or Mikuni 28mm from RD.

    Which is the best carburator that i can add to my setup to better the existing??
    All bike gurus and geniuses.......
    Xbhp masterminds kindly help.......
    The Man and The Machine!!

  • #2
    Query Approved.


    • #3
      2T carbs can difinitely be used. The advantage of using VM type or TM type carbs is precision tuning. You can go for a VM carb, but i would say go for a 26mm instead of 28. Thats coz a smaller carb that flows very well will perform better than a large carb, all over the rev range.


      • #4
        I i had used a VM26 on a Fiero... the performance is amazing, but mileage drops a lot...... and do go in for a free flow air filter.....
        We do it sideways !!!


        • #5
          A few things to consider when opting for a different carb on 4-strokes.
          * Cubic capacity
          * Venturi size of the carb
          * Valve size
          * Cam profile
          * performance expected/rpm desired.

          A 29mm CV carb has a 1mm bigger venturi than an RD's VM28. People would use the older tech carb coz they have no choice in the past.
          Fuel metering is better with the modern carbs and CV carbs are best suited for 4-stroke engines.
          If you are running a big bore engine with a stock head, your performance will only drop. your engine will be slower than stock. You need to modify the engine to make up for the increase in CC too.