Jetting

[mudfreak99]

I am building my 250r as some of you may know and I am about to get a carb, what size main jet do these come with stock, and what size should I go to with a K&N, I am assuming to move up a jet size but I don't know what size that would be, I love in the hills of KY so i really don't know how highg I am. any help is greatly appricieated.
Josh