LOP/ROP arguments about Jabirus are missing the point; with a Bing Carburettor and no EGT probes, who would have the faintest idea of what is going on.
Furthermore, Jabirus issues have nothing to do with mixture and everything to do with basic mechanical design.
1. The lack of a head gasket makes the head/cylinder joint a weakness because of differential expansion and permanent distortion.
2. (1) means that valve clearance setting is problematic. That leaves valves vulnerable to sticking/burning.
3. Through-bolts are marginally too weak and clamping forces are not enough to prevent fretting without permanently deforming the heads (see 1.).
4. Perhaps most importantly, Jabirus use of fully CNC machined heads puts a limit on the number of cooling fins. the tool that cuts them has a maximum width/ depth ratio that cannot be exceeded ( its a machining thing) so there are not as many fins (more surface area) as ideally should be present to cool the head. A cast head with more and finer fins would be better from a cooling point of view.
Sadly, the last aerospace quality foundry that could have cast such heads was at CAC ands shut down due to stupid accounting practices that falsely indicated it was unprofitable.
5. Finally, the factory management either can't afford or won't contemplate product improvement, leaving them with no choice but to close business and sell it to someone who has the funds and attitude necessary for product improvement and professional customer service.
Jeez I'm glad I forgot about this motor.