My 575 sci has done this twice in 100 hrs. Worried as well that it was rear seal on a new motor. Both times the only thing I could find in the area to tighten was the oil cooler lines as a possibility. Both times they seemed very tight but re-torqued anyway and oil disappeared on my next trip out. Still don't know if it really is the lines or coincidence with another intermittent oil leak issue.

Thanks I will get in there and check some bolts out in these areas.

Intake valley area?