Mercury - 48-Volt Alternator Belt High-Output Charging System Reinforced Composite 8M0207416. Overview. When you run a modern high-horsepower outboard, you're not just powering an engine - you're supporting an entire electrical ecosystem. Big screens, high-draw pumps, lighting, audio systems, gyro stabilizers… everything depends on steady, reliable charging. And that's why the alternator belt matters more than most people think. With the Mercury Marine part 8M0207416, you'll feel the quiet confi