I had a 1966 S90
I rode it on the roads and trails in the Willowemoc area of Sullivan County NY.
Engine would rev to at least 13k, hard to tell exactly, had to extrapolate from gear shift points on speedo. it would freely spin way above the indicated shift point.
Had as many as 3 teenage boys crammed on it, cruising the roads and trails.
It got caught in a flood, became my first restoration, tore it down to drain all water. cleaned, oiled, new battery. It lit right off and we rode it for years.
Straightened the front forks in our basement window with a set of wood blocks and a small hydraulic jack. this was after father ran into the back of truck, he might have been impaired...
Still have knob on knee where I took a short flight over a berm and caught the chicken wire fence with knee...
Took Lynn A. up to Blueberry hill, had a great make out session, got to cop my first feel...
Left to younger brother when I went to college, think it wound up in the scrap yard, little brother not much of a wrench.
Life is good...
Wish I had it now.
Mark