this reminds me of when I was a kid, the older brothers of one of my school friends raced an outfit with a Z1 900 motor, on Christmas day, after they’d had a few Xmas bevies, they were known to fire it up and do laps around the neighbourhood at high speed, I saw them get it airborne once or twice, then when I was a bit older they heard I had Z1 that I was rebuilding and they gave me the head and various other bits off it, I always regretted never going to see them race.