Skip to 7m30s
Another reason why I'll never take my bike on that road!
Not sure how he knows the air filter is clean on the zx7r unless he has xray vision you need to take it apart and check the inner filter a good wash will give the bike a big lift but then perhaps that was just for the camera and has been done
I had similar thoughts - if he was really worried about weight then a wash would remove 5kg of dirt! But I guess it is enthusiast entertainment, and I'm not really bothered about the details.