CA02midnightstar

This may have been answered here before, but I have a question about my 02 RS Midnight Star 1600. My bike starts to crap out (sputter, little power) as I am upshifting throught the gears, especially if I get on the throttle. Basically it feels like it has a governer that kicks in very quickly and forces me to upshift to have power back again. The owners manual gives recomended shift speeds for each gear, is this part of the issue? This becomes somewhat dangerous when passing cars etc, because of the power loss in each gear. Can I fix this issue? Is this the rev limiter, a governor, or what? Any help would be appreciated. Thanks FYI Mostly stock bike except for the following mods: V&H full exhaust K&N type open Air filter