If you haven't changed the intake only the exhausts you could run happily on the standards and adjust the pilot screw to run slightly rich. This won't improve performance but will sound well,
(i ran mine for 12 months with this setup) you need to rejet carbs when adjusting both admission and exhaust. (I now have short "open" TORS and modified airbox) the increase in airflow has to be balanced to an increase in fuel. I have a "colourtune" spark plug insert. Great for tune ups and getting your fuel ratio just right at all rev's.
