not a big difference but a noticable difference , i am curently using the Boysen power reeds #607 . it helped spread the power band or lets say it helps the bike rap out to that next turn without haveing to reach for another gear .
I don't race .... except with my crazy friends who go way too fast. I'm good enough backyard mechaniic to work on my own bikes. Been riding my 92 kdx 200 for a year with FMF pipe & no air lid. Recently added Boysen dual stage reeds & re-jetted as per guidelines in the Boysen instructions. Huge difference!! Instant wheelies thru 3rd gear. The bike pulls stronger faster from 1/4 thru the top. Much more fun.
Domino Dave