crank seal

See the 912ULS Installation Manual Section 79-00-00 pages 6 and 9.

Did you wait for the Oil to reach 90°C before measuring the crankcase pressure?
If your Vent Line is too small for its length, the restriction pressure will reflect back into the crankcase.
Try it with the Oil Cap Loose to see if it makes a difference.

It has recently come to my attention that the current Pressure spec is a more realistic 0.6 bar (8.7 psi).

See the NEW 912 Installation Manual Edition 3, Rev 0, Section 79-00-00, Page 8

I did bring up to 190 f then to235 full throttle 5100 rpm. It went to 8.7 then backed down to around 7.5