Here's a couple of experiences from the mis-spent youth.
When I was young and stupid, I bought an ex police BSA (we'll ignore it was an A65)
It would do 96mph max (on the speedo) and could not be induced to go faster however long the throttle was held open.
This machine had a key in the headlight. the key had to be removed after the bike was started or it would fall out.
In another attempt to reach the magic ton, I took it on a full throttle run down a long slope, well out of town.
It reached about 97mph before I needed to shut it down for a railway crossing.
I closed the throttle and sat up expecting to slow down fairly rapidly.
It was a bit disturbing when the thing continued on down the road at full bore.
We may have been airborne crossing the railway line. I was too busy feeling in my back pocket for the key to notice much.
After switching the 'Blo*dy Scarey Auto' off, coasting to a stop and smoking half a pack of camels, I found the top of the monoblock had unscrewed. When I shut it down the top of the carby popped off instead of pushing the slide down.
That monoblock had a hose clamp screwed around the top in less than an hour.
On another occasion, a mate and I decided to catch a car full of young females who had left town five minutes earlier. We managed to get the old girl up to 90mph or so and eventually spotted them in the distance. We were about 20 metres behind them when I shut it down and sat up, once again expecting to slow down rapidly.
I knew cars create a vacuum behind them but I didn't expect the bike to go faster when the throttle was shut. That's what it seemed like anyhow. In the blink of an eye we were on them. Some how I got it out enough to pass, though we must have just about taken their door handles off. We lost interest in the lasses after that and I think I still carry my mates finger marks to this day.
Each of these occasions could have ended in disaster. We didn't wear helmets then.
I lost a couple of mates in the old days and looking back it makes you wonder if it was a similar unusual event that took them away.
Cheers & Take Care