Thats one of the things I dislike about forums. And you are correct. Limited and vague information... I see a guy from Italy, struggling with his bike. This is a US based site that uses English and US weights and measurements. I have no idea what he's getting for fuel economy and I'm not going to figure it out. I have to take his word on the switched air filters and that they are ok. Again, I agree with you about the K&N. It's either over oiled, or it's ok. If it's ok, then it will lean the bike out, coupled with very lean jetting from the factory. He said it's ok. I too would prefer that a new Honda filter be used. Thats what the bike is jetted for. He doesn't seem interested. So be it...
He apparently has sooty plugs and his milage is off a little. He wanted to deliberatly mess with the mixture screws and couldn't get the special tool. So, pull the carbs and set everything up properly while they're out. He still left the mixture screws at only one turn out and wants to put the floats back to 9mm because it's worse than when he started. If the carbs are set up properly(which they're not) and still getting black plugs, something else is going on. Possible weak ignition...
My '94 ABS and others that I've set up, run perfectly with a Honda air filter, idle mixture screws set at 1 7/8 turns, floats set at 7mm and .020" shims under the needles, with OEM jets. This is ideal for my area.