Mercury - 300 Hour Maintenance Kit MerCruiser 4.3L MPI Bravo Series OEM Service Components 8M0147065. Overview. There's something steadying about knowing your engine is truly prepared for the long haul. When you run a MerCruiser 4.3L MPI paired with a Bravo sterndrive, you expect smooth pull, dependable cooling, and a throttle response that feels clean and confident every time you ease forward. The Mercury 8M0147065 300 Hour Maintenance Kit brings that reassurance back into your routine. It's th