My 2005 Kawasaki Ninja 500 is not accelerating past 5000rpm. It will not go much faster than 50mph either. This just started happening today, with no signs before. My friend says its related to a fuel filter, but it seems the Ninja 500 doesn't have one in the traditional sense. In neutral it will rev up just fine. I'm worried it will crap out on me in the middle of the road so i don't want to take it anywhere unless i absolutely have to. Does anyone have any ideas?