Mercury - 300 Hour Maintenance Kit Verado & SeaPro Series Factory Components 8M0149932. Overview. When you run a big V8 offshore engine, you get used to depending on it in a way that's almost personal. You learn its sound, the way it settles into a steady hum, the way it pulls when the water gets a little heavy. And because you rely on that engine so completely, you want to know the maintenance you're doing is the kind that actually preserves that confidence. The Mercury 300 Hour Maintenance Kit