Frankie Marotta

Whats goin on my name is frank im in lower bucks county pa.. i just bought a 2000 cbr 600f4 w about 29000 on her. Bikes a little beat up but always wanted one and was pretty cheap so i kinda just jumped on it. The problem i am having though is i will be cruising along usually above 40 and itll start to sputter and if i try to rev it up sounds even worse like its not firing correct. As soon as i back off it just dies completely.. also seems to v happening when its really hot out when i roll to a stop and hit the starter it struggles to fire back up then itll just come back like nothing was wrong.. really wanna get this resolved so i can just ride w.o worry any help is greatly appreciated it