disappointed with my cns carb

Discussion in 'Motorized Bicycle Trouble Shooting' started by hcrft, Mar 9, 2013.

  1. hcrft

    hcrft New Member

    Jan 4, 2013
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    my schwinn is destined to have a performance carb, boost bottle, nitrous, a tuned pipe , and shift kit. i decided to start with a cns carb. IT SUCKS. the only time the bike makes any real power is right before the engine runs out of fuel. otherwise, if the fuel valve on the tank is open, the engine is flooded, and bogs down when i open the throttle.if tried all the obvious combinations of needlevalve settings, fuel settings (from rich to lean), covering or uncovering the two tube ports on top of the carb, and the results have been different variations of the same problem.im going to go back to the stock carb, and if the jet in the cns carb is bigger than stock, i will swap them. SO DISAPPOINTED in the carb!!
  2. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

    Jan 8, 2008
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    Wait until you install the boost bottle...
  3. maniac57

    maniac57 Old, Fat, and still faster than you

    Oct 8, 2011
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    Yet another person who did not know what they were buying, just heard "FASTER!!!"
    The CNS needs to be tuned to work right by someone with some understanding of exactly what a carb does and how adjustment changes things. You should read up on tuning these carbs here in the forum before you get mad. There is plenty of information if you take the time to learn and you will surely have much better results than just bolting stuff on and nailing the gas....
    There is no such thing as a free lunch.
  4. Greg58

    Greg58 Well-Known Member

    May 1, 2011
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    The cns needs the float set correctly to compensate for the carb angle, if yours runs better right before it runs out of fuel try bending the float tang to close the needle sooner. As for the jets they are not the same thread size as the nt.

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