Mercury - 300 Hour Maintenance Kit MerCruiser 4.5L MPI Bravo Series OEM Service Components 8M0147067. Overview. When you run a MerCruiser 4.5L MPI engine with a Bravo sterndrive, you get used to a certain steady confidence. The kind that comes from crisp throttle response, clean acceleration, and no surprises when you push the boat into open water. But even the most dependable setup needs its big check-in. The Mercury 8M0147067 300 Hour Maintenance Kit brings that familiar reassurance back to yo