I was out yesterday. At 5000 rpm I was doing 114 kph, measured with a GPS. But I gave bad numbers for my sprockets. I currently am using 16 & 35. (I had forgotten when I rebuilt the bike I used a Z1 sprocket to save a bit of money.) The bike has 630 chain.
I have a couple of Z1B's restored, an '80 KZ1000LTD restored, a 1981 KZ550 restored and a 2008 KLR 650 for off road fun. My wife has a 2019 Suzuki DR 650 for on and off road.