Recently acquired a 2013 300, bogged a fair bit but otherwise ok then started to detonate once hot. Stripped the head off and it was fully carboned up, cleaned it all and checked jetting in the keihin which was running a 120 main 48 pilot and a jjy needle. Set carb back to what I gather it should be as a 125 48 and jjh. Ran really well nice and crisp but it’s still detonating once warm and the plug is covered in black soot still. Tried the air screw in every possible position I can think of but still does it, am I missing something really obvious? Any help or suggestions would be gratefully received 

I seem to recall the 2013 300s were prone to this and a change to red cylinder head was the cure. Haven Trialsport can advise I think.