1. Cooling by forward motion is not present.
2. The revving was after initial start up, in old motors it takes time to build oil press and delivery.
3. No load means it's not producing any torque, some say it will spin beyond safe when gas is let off. I don't want to see if that's true, if anyone does, go for it.
4. We all rev, just don't rev high or long to be on the safe side.
5. Some, so called, mechanical engineers say no load/no torque will cause parts to "stretch" during high revving and pistons, for example, can get beyond the ring ridges.
6. Old motors are designed for clearances at operating temps. So during cold motor revving, clearances are at max loose.
