I would check in this order Caps and Leads, Plugs, Air filter, then carbs, clean and balance,
I was chasing a similar issue on a 600 recently and went in the opposite direct to find it was Plug Caps/leads/coils breaking down when hot and tracking. Swapped the caps for NGK ones and it improved a bit untill I finally changed the lot.
Bought a set of very Clean Coils and caps (no corrosion/tarnishing at all internally) for €50 and it sorted the problem.
It was an issue I had not come across before on the Fazer
Breaking down when hot is a pain because when you start it cold it is fine, which pointed to carbs
I was chasing a similar issue on a 600 recently and went in the opposite direct to find it was Plug Caps/leads/coils breaking down when hot and tracking. Swapped the caps for NGK ones and it improved a bit untill I finally changed the lot.
Bought a set of very Clean Coils and caps (no corrosion/tarnishing at all internally) for €50 and it sorted the problem.
It was an issue I had not come across before on the Fazer
Breaking down when hot is a pain because when you start it cold it is fine, which pointed to carbs