Is the CNS carb really worth it?

Discussion in '2-Stroke Engines' started by geebt48cc, Jan 28, 2011.

  1. geebt48cc

    geebt48cc Member

    Uno, I've been reading about this carb with hopes that I'm going to be happy with it? See, just finished my Skyhawk 66cc Slant, with the new CNS. I've yet to have the weather for its first run. It did install nicely, but after reading so much negatives about this new carb, I'm scared I'm going to be very disapointed?

    The only thing that I've yet to do is fill the tank with gas. Guess I'll start out with 20:1 this time, for break in. So, is there anything good out there about this new CNS that I'll soon be firing up? All I have seen on here is, leaks, hard to start, doesn't idle, bogs?.....etc

    (Gosh, haven't even started it yet, and everything about it sounds dismal?)

    PS: .......and I thought the old style carb wasn't the best? :bowdown: Sheezeee......

    Any advise? Thanks, Glen

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    Last edited: Jan 28, 2011

  2. GearNut

    GearNut Active Member

    First, let me say that I am only passing on hear-say. Take it for what it is worth.
    From what I have read on the "other" board, it appears that the black seal that goes inside the carb's spigot mount does not seal well enough to make an air tight connection due to the gaps that form the clamping portion of the carb.
    You need to use fuel proof sealant in the gaps of the carb casting where the carb clamps to the manifold. The OP of that thread only sealed the gaps from the outside and did not use any sealant on the inside of the carb spigot.
  3. geebt48cc

    geebt48cc Member

    Yes, believe I saw some of that about this new carb. I wonder if I can use the sealant just around the exterior when CNS is firmly mounted to manifold? Uno, this does sound like old HT carb days...............Really was hoping that they engineered past the old days?

    Hey, it's worth a shot. TY
  4. sideshowbob

    sideshowbob Member

    I've tried both types I like the old style better and I get better performance from the old ones. They are easier to adjust, simpler, and have only 1 cable. To adjust the CNS which they will need you have to carefully break the sealant they put on the adjuster screws , heat it up and it will break the seal easily. Then be careful to use the correct size screw driver to adjust them.look both have the same size intake and volume is what determine power. If it can't suck in more air volume it can't be more powerful. I say stick with the old style. They are simpler and in my experience they work just as good or better. Like the boost bottle I think it's a waste of money. Simple is good.
  5. geebt48cc

    geebt48cc Member

    Well, Yes Bob, I would say your right with the carb game. Did the CNS (when running ok) help at all power wise? Gosh, I would of thought that it would almost have to considering it does cost a bit more than standard.

    Uno, I live now in Va, but Oregon is a awesome place. I do believe that would be my pick on West Coast......... lol, as long as I could have my "China Wonders!~"

    Pretty bike also...they are fun!~

  6. sideshowbob

    sideshowbob Member

    some say yes some say no, I say no

    Some folks on this and the other forum say that they have more power with the CNS. I don't think so based on volume of air from diameter of the intake. My CNS ran ok once I tinkered with it, but it took much more carb savy to get it to run right. The old style one I just slapped on, turned the idle screw all the way in and off I went, nice idle too. The CNS does have a separate choke circuit, slide and cable which means if running right it would be less likely to develop a lean condition at hi RMP or temps and would be more adjustable with hand on bars. But it took way more fiddling to even get it to run out of the box. I think most folks think they are getting more power because of the K&N style filter is less restrictive (more air). but you can buy even nicer K&N style filters from sick bike parts for the old ones. Mainly I think that the intake is the same diameter as the old ones so the air intake volume cannot be more (unless the air is thicker (see level) Its the volume of fuel./air per stroke that determines how much bang or power you can get. If you can increase the volume going in you would in theory get more ummpphh. But I think I get just as much with the old style and its way easier to keep running right with less tinkering and being less complex there is less to go wrong. I don't mind the flap type choke, heck I only have to use it for maybe 1 minute even on cold day starts.
    Last edited: Jan 28, 2011
  7. sideshowbob

    sideshowbob Member

    Those expansion chambers like the one in your pic with a good NGK plug will probably give you the most power for the cost. The theory behind those is good and they do help the engine to breath but i've heard some folks need to change jets when running an expansion chamber for maximum effect.