Adjusting the New 2011 CNS V2 Carburetor , It sounds like the choke! When its cold turn the choke lever on then when you get it started turn it off but not all the way off. Or till it warms up to what seams the operating temperature. As it warms up turn it off, or almost all the way off. The choke when all the way On is cable pulled. Off is cable not pulled. If the mini handlebar choke lever does not hold tighten the screw on the choke lever. Also you might have to find the right position of the C clip on the needle valve on the slide pin. Then adjust the air fuel mixture screw and the idle screw. The C clip has 4-5 positions, richer means more fuel has more power off the line, leaner means less fuel winds up more RPMs on the top end, find the best position. Move the C clip down is richer, clip up is leaner. In other words if the needle w/ the C clip on the slide is longer on the bottom of the slide it is leaner as it goes deeper in the jet hole. Leaner thinner is less fuel. Also the engine needs to go through the break-in period about 2-4 Tanks or 1-2 gallons then it starts to run better. Also make sure your clutch is adjusted correctly. In other words if there is a little drag at an idle it will stall the engine. How to test! At an Idle hold up the rear wheel of the bike if the wheel turns w/ the clutch in pin lock position then there is a drag on the engine. Try adjusting the clutch cable or the clutch. There should be no drag on the engine at an idle. Then adjust the air fuel mixture screw and idle screw.
Hope this helps someone!