Just out of curiousity, what would you recommend for a mod for an F4.

something to give it a little more torque/acceleration.

right now, my baby's got:

Yosh RS-3 slipon
K&N filter
Down 1 tooth on the front sprocket from stock

Not sure if the previous owner mucked with the jetting (i..e. put in a jet kit).

Presumably, I can't tell if the jetting's been changed w/o taking the carbs off.

I've been told that

1) a dynojet kit is highly recommended
2) to advance my timing (also recommended)

anyone tried these on an F4 (or other bike) and noticed a difference??