Well, with the Katana, just re-jetting the carbs will not work. the problem is the back pressure created by the airbox. When installing air pods it screws everything up. Even if you jet the carbs. Theres a lot of tedious work involved in getting a Kat to run properly on pod filters. Jettings, air restricters, F/A mixture adjustments, and a timing advance are among the main things needed to tune them correctly, after extensive research I've found that the katanas made for the UK and australia are tuneable but still, not without a dyno and a hell of a lot of patience.
Im just curious to know whether or not it will be that involved on these xs's. You pretty much cant get the katana to not have flat spots in the Rpm, they pop, it makes the exhaust sound more like a wet fart than "sport" bike, it all around makes them run crappy. I know this isnt the case with other model bikes. I can provide links to backup my information from the Katriders.com forum if you would like to read about it, but not all bikes are so picky about pods. This xs400 i just got has pods, the dumbass put mismatched pods on it so i will be getting a new pair. Im going to have it jetted, clean the carbs and get new intake boots but i have a feeling its still gunna run a lil funky.