Mercury - 300 Hour Maintenance Kit MerCruiser 5.0L, 5.7L & 6.2L MPI Bravo Series OEM Service Components 8M0147069. Overview. There's something comforting about an engine that responds exactly the way you expect. When you ease the throttle forward and your MerCruiser MPI settles into that smooth, confident push, it's a reminder of why upkeep matters. The Mercury 8M0147069 300 Hour Maintenance Kit brings that peace of mind into one tidy box. It's crafted for boaters who'd rather spend their time o