2000 2.5L merc efi hissing sound
I was just out cleaning the boat up for winter. Ran the motor in a barrel without the cowl and noticed a hissing sound. Sounds like a vacuum leak to me, never noticed anything while using the boat this year. Motor ran great just last Saturday. While searching I found that a lot of people had issues with the oil injection check valves. The previous owner removed the oil injection, I imagine that the check valves would have been removed too.
My only experience with chasing vacuum leaks is on cars. This leak sounds bad enough that it would cause running issues, at least on a car. Any ideas on where I should start looking?
Thanks