more then likely your clutch m8 i have same problem when i took the kickstart case off there was a snapped clutch spring jus rolling around...put ur bike on the stand, try turning the wheel with your hand with the engine off does it move freely or does it feel like its in gear? if in gear then its more then likly ur clutch or clutch springs both not major problems and fairly cheap and simple to fix :)
matty
November 2010