Hi, When revving hard on the highway with my 2001SY, the bike starts to cough and splutter, slowing me to a crawl, as it's not revving cleanly. It ticks over ok without any throttle twisted on, but as soon as I twist the throttle back on, it starts to cough and splutter again. This seems to clear after a few minutes and everything's ok again. This only ever happens on the highway, and never off road.It seems to make no difference if it's in the dry or the wet. Fuel tank can be full or near reserve. What I've tried / checked so far. There's no water in the tank. The fuel screen is clean I've tried running with the petcock on both Res and On I've done the kick-stand switch mod. I've tried running without the fuel cap, just in case it wasn't venting properly I've not changed anything related to the carb I reckon it must be a fuel starvation or carb problem Please HELP!!!!