why is my speedfight 2 cutting out?

i have a 06 speed fight 2 i was recently going up hill and my bike just cut out it starts after it but then it doesn't respond wen i pull the throttle so i took my carb off and cleaned my jets out and it worked 4 a while and then it did it again whilst going along on a straight road and i repeated the process of cleaning my jets out again, and it is now working. it has only just started doing this could, it be dirt in my fuel tank? my fuel mixture? or type of oil i am using? i also have the bike derestricted so would i need to up jet it? i would be greatfull for an answer