how would i go about cleaning the carb?
First question I have is what kind of air filter do you have on your cns carb? If you have the red plastic filter the first thing you want to do is pull the filter and wash out the foam insert, they are notorious for clogging up from blow-back and screwing up the air/fuel mix (making the motor run rich when clogged), if you have the cone style high flow filter this shouldn't be a problem.
Cleaning the carb is pretty easy. First pull the two screws off the top that secure the cables, then pull the cables, slide and enrichment jet plunger out of the carb (just pull straight up). Remove the air filter if possible, you don't want it to get soaked with premix fuel and get clogged up. Then loosen the carb neck and slide the carb off. At this point you can pull the drain screw from the bottom of the bowl to drain out fuel (if you want). Then just pull the 4 screws out of the bowl and split the bowl from the top half of the carb. Now just blow the inside of the carb out with carb cleaner, there are 3 jets in the CNS carb, the main jet, the idle jet and the enrichment jet, make sure you blow them out well. Pay special attention to the idle jet, the opening in it is very small and sometimes the force from the flow of carb cleaner isn't enough to clear it out, I usually run a thin wire (like the wire from inside a twist tie) through the idle jet to make sure its cleared out (don't force anything in there, use something that fits through easily). If you want you can pull the float and blow inside the needle valve housing clean, or you can probably get away with just blowing carb cleaner down the fuel inlet to force out any crap that may be in the needle valve. Then just reassemble the carb.
When you install a CNS carb keep in mind the that they have a rubber seal in the neck of the carb, this seal is formed to fit over the end of the intake. When you install the carb push it down until is seats all the way on the intake, then wiggle the carb around a bit while pushing it on the intake, this will help get the intake seated into that seal (before you do this you might want to pull that seal out of the neck of the carb and fit it on the end of your intake, just to get an idea what you are dealing with, once you see how it fits you should understand what you need to accomplish when mounting the carb). Finally, when you are tightening the screw on the neck of the carb make sure you are pushing the carb firmly onto the intake to make that seal. If you do it this way you wont have any air leaks. When you insert the slide into the carb note the slot on one side and make sure it goes over the pin you see inside the carb, otherwise it wont go down into the carb like it should (the enrichment plunger can go in any which way, it has no slot to guide it)