Been chasing this problem around for awhile. 20k mi. 05 GSXR 600. Problem started about 6 months ago, and progressively getting worse. After the bike is warmed up there is a sputter at idle, but its not consistent. Feels like a cylinder is misfiring or fuel is off or something. The whole throttle body has been changed (Fuel rail, injectors, STVA, TPS, etc) and had zero effect on the problem. Battery has been changed and tested, no effect. Plugs have been changed, no effect. Air filter has been changed, no effect. Any idea where to go next? Was going to get new wires for the spark plugs next.