aerox rattling but dont know why please help

hi iv got a 2007 aerox 2764 km on a new doppler crank and about 450 miles on a pm 70c head and changed the rollers and changed the belt and after tht it is knocking/rattling really bad ..it has a 90 jet and 4.5 rollers ...could it be bad bearing or piston knock ..how can i tell

please help dont want to ride it incase something goes pop
specs

doppler endurance 10mm crank
pm 70 head
21 mm dellorto carb (90 main)
v-force reeds
mallosi vario (4.5g) with stage 6 cnc drive face
pm clutch
malossi belt
polini race pipe
pm gear up kit

 

I'd check the small end bearing, piston rings ect, then the transmission for anything that might be wrong. Specially clutch nuts, vario nuts

 

Turned out thread on varitor had worn and kept cuming lose so just put a waher behind it and it was fine ...simples

 

Ahh not too bad then