the overheating event was indeed a climb out issue where number #4 skyrocketed above 200c with a CFI and an instructor at the controls.
393 deg Farenheit = 200 deg celcius.
This is a standard Jabiru CHT gauge; note the markings.
So you say that an instructor lett his happen? Normal operating temps are 275f / 135c
With all due respect I would consider taking your aircraft offline from that flying school.