I had the same problem with my wifey's bike 2001 ninja 250. yeah the jets the jets the jets ......... on the side of the carb is a white plastic circle with two screws holding it. under that cover is a diaphragm with a spring return so be ready to catch it.
there are two things to do here with carb clean and compressed air.
1. the cover has a small pollup with an air passage towards the diaphragm that needs to be cleaned and blown
2. the diaphragm holds a metal penis type thingy that needs to be cleaned and blown also
3. take the bowl off and clean the jets
4. satating the obvious here but you did change out the gas in the tank ... right?
5. you don't have to separate the carbs to do this op.