60hp 4 stroke Mercury using oil

[MitchBrown]

My 2004 Mercury 60hp 4 stroke efi is using a lot of oil. Like a quart in a day! I had the boat at a mechanic he did a compression check all cylinders were 140 to 150. He also did a leak down check and said it was fine. I was wondering if there was a crank case breather or something not letting it breathe causing it to build pressure in the oil. The motor runs great, just uses oil. Any ideas would be appreciated, thanks.