High Oil Temps - Pipistrel Virus SW

What are your actual oil temps? 230F -245F during the summer hotter months can be normal. Seeing temps in the yellow is no big deal yellow just means hey take a look at me and make sure I don't go into the red. yellow is just your attention getter. That said the oil temps should go back down when you level off and reduce power which reduces engine load and should allow for more air flow through the cowl when in level flight.  Another way to help engine temps during hot months is to take off flatter with more speed to reduce engine load and keep more air flowing through the cowl.

What size is your oil cooler? I upgraded to a large oil cooler with a oil thermostat and my temps now are normal in all temperatures and phases of flight.

Keeping tight turns out of oil hoses helps too.

i suggest you for big oil cooler , as Garrett Wysocki also mentioned.

The below link is from kitplanes "Oil Cooler 101" visit please

https://www.kitplanes.com/oil-cooler-101/

I struggled with high oil temps for several years and in spite of 2 strip-downs and rebuilds we could never find the source of the problem. Eventually I swapped the engine and that solved my problem. I kept the original ancilliaries including the oil cooler and hoses so I know that there was an issue in the old crankcase or heads.

I know that this may not be helpful but my message would be don't spend too much time and money on trying to fix the problem with your existing engine. There comes a point when you have to cut your losses and get a replacement engine. I should have done this before my second rebuild, that would have saved me a year of fiddling and a fair chunk of cash. I hope that your's has a simpler and cheaper solution!