And for Rotax 912(S) there is the "avoid cruising below 5000 rpm" camp...
Theres good reason for that!
it avoids this..
This is very hard on the mechanical parts of the engine and it creates a lot of heat which you read on the CHT gauge. Imagine riding a bicycle and applying maximum pressure to the pedal at the top or just before the start of the down stroke. You may push as much as you like but nothing much happens till you obtain quite a few degrees of mechanical advantage.
very similar effect on internal pressures as running LOP..... sharp drop of in pressures...and hence, temps..
the events described above, the high pressures, running at the worst ROP mixtures, i think are part, if not most of the issues facing the Jabiru engine failures... how do you snap a bolt under tension? with a lot of pressure.. repeatedly..