A tappy Guzzi is a happy Guzzi ??
I’ve read differing views . . . . Mandello sorcery says 0.10 intake and 0.15 exhaust. Other sources (an old Raceco spec for one, I think),including some American forums, promote 0.2 & 0.25 respectively. If we “open up”, do we lose some grunt and rattle more, or does she breathe a little more freely, tick over better and say thank you ? Conversely, did mother know best ?
I can only say that more generally, from my understanding, US bikes tend to have a tighter clearance specified just to reduce noise emissions. The engines run better with the more open gap. No clue if this would be applicable in your application.