When you get ready to rejet there is a mod we call a poormans BAK
that you can do to your stock air box when using the K/N filter. It will let the bike breath better and it is a free mod. You will need to get into the carb
when you change to an aftermarket exhaust. Just come and ask any questions here and we can get you thru a rejet without a problem. Its not a hard job. Especially if you have just a little mechanical ability.