What is a yoshi system. I'm not familiar with that. I just got 2015Yamaha FJ-09 last July. I've done a BMC airfilter, Competition Werkes Slip-on, Ivan flash, Galfer wave rotors, Sargent seats, I've got Andreani fork cartridges ready to go in and will do the slipper clutch by mid summer. My bike loves to wheelie in first, second and third.
Help!
I hope that you find and fix the problem. Sorry that I couldn't be of help yet.