The only reason there are read valve engines is because of the LMR (Lamello-Margay-Reed). IKF had this brilliant idea to stop calling it the McCullough class. They wanted more chainsaw manufacturers to get into the game, so they called the class, get this, "American Reed". They had no idea somebody would build something like the LMR. It was American! It was reed! What's the problem? Totally superior to the McCullough. So they changed the rules back to McCullough class.
The Italians, seeing that we had invented an "American Reed" class, built the K55. It was much better than the LMR. A lot of Americans liked the K55. So there were other Italian engine builders that thought, "hey, we can do that". And that's why we have reed engines today.
For years, IKF lived with the idea that there was no karting anywhere else in the world. That they ruled and could do anything they wanted.
When the Yamaha came out, and I was at the board meeting where it was approved, they made the decision not to call it the Yamaha class, rather they would call it the piston port class. And that was fine until the Italians decided, "hey, we can do that to" "and better". And it was true. So IKF had to change their mind again and call it the Yamaha class. If they hadn't changed their mind, there would be no Yamaha's today.
IKF once ruled, from their throne on high, that a go kart motor could not cost more than a $100 retail. You could buy them wholesale for $65. IKF had to dumped that rule when they approved the Yamaha.
You think the rules makers just started making crazy rules? I don't think so.