I have tried to fine tune the PC3r myself. I have even read up on several suggestions in bike mags and reviewed old posts....nothing has helped. I tried to lean out the A/F between 2k-3k by 7-8% and cant really tell the difference. I have tried to adjust the A/F using the buttons on the PC3...I went leaner by 6% then richer by 6%....no help. Does anyone have suggestions? I started with the yosh map from the PC website (i have the rs3 duplex system) and went from there. With the yosh map all is well above 3K rpm....should I just forget the stumble? Closest dyno is 3 hrs one way!