Unable to answer why other then increasing pressure will help keep it sealed. Testing at 3 psi and rotating shafts "may" show something. A vacuum test may also
I didnt do vacuum test, only pressure test+rotating the shaft and nothing, no pressure drop, no bubbles..
Do You think to fix it or live with it? I know the prop seal is real pain to replace...
Guess it depends on how much. No one likes putting oil in the water but if your loosing a few ounces all season I would live with and recheck every year. If your loosing more, then might want to go for new seals
