lmcbf500

Hello all. Need your help with an issue on a CBF500 2006 which I bought recently. It had low miles and when I drove it home the bike was fine. Close to home it started running rough - low power (would not go up steep hills for example). The bike had sat for extended periods of time. On getting home it had a rough idle. The petrol smelled off like paint thinners and a bad colour so thinking it was probably off-fuel I drained the tank and cleaned the carbs and jets out. Put the bike back together and she now idles good and revs smooth at standstill and I can rev to the redline but on the move has a general lack of power (comparing against an identical bike of my friends). In low gears the throttle should be urgent and it accelerates at maybe half the rate it should. In higher gears it might only get to 5 or 6k revs due to the lack of power. Bike still feels like it is running smooth, just under powered. I have also replaced plugs, checked stator voltages and checked regulator. The bike had a new battery fitted also. Anyone have any ideas based on my symptoms? Forget what I have done/checked - based on my symptoms what do you guys think the issue might be or where should I start to troubleshoot? Thanks in advance