Mercury - Timing Belt 30-60hp FourStroke Series Reinforced Construction 8M0151040. Overview. There's a certain rhythm you get used to when you spend enough time on the water - that steady, reassuring beat of a well-tuned outboard doing exactly what it's supposed to do. When that rhythm is right, you don't think about it. You just enjoy the ride, the wake, the quiet glide past a shoreline you've seen a thousand times yet never get tired of. A dependable timing belt is a small part of that peace o