Mercury – Serpentine Belt | Engine Drive System | Rubber Composite | 865615Q01

Overview

There’s something calming about knowing the heart of your engine is turning exactly the way it should. When you’re running a big block like the MerCruiser 496 Magnum, every accessory driven by that serpentine belt plays a part in keeping the day smooth—whether you’re easing away from the dock at sunrise or trimming up for a long run across open water. A dependable belt isn’t flashy, but you feel its importance every time the throttle responds without hesitation. This Mercury Marine part gives you that quiet confidence that your boat is ready for whatever the water brings.

Key Features

• Designed to drive essential engine systems on MerCruiser 496 Magnum engines
• Built from a durable rubber composite formulated for marine environments
• Measures 2,830mm in length for precise factory-matched fit
• Matches the original belt installed by MerCruiser
• Engineered for stable tension, clean tracking, and long service life

Engine & Boat Compatibility

• Fits MerCruiser 496 Magnum engines
• Compatible with serial number range 0M025000 through 0W309999
• Commonly found on performance runabouts, sport cruisers, tow boats, and larger offshore vessels
• Suitable for both sterndrive and inboard configurations that utilize this specific drive setup

Performance & Practical Benefits

A serpentine belt may look simple, but its impact is anything but. With this Mercury Marine part, you’ll feel the difference in the way your accessories operate—steady alternator output, consistent cooling flow, smooth steering assist, and a tight, responsive feel across the entire system. The correct belt maintains proper grip and tension, which means fewer slips, fewer hot spots, and fewer surprises when you’re miles from the ramp.

Because it’s built to match the exact specifications of your original equipment, installation is straightforward. The belt seats cleanly into the pulleys without that awkward stretch or slack you sometimes get from aftermarket options. Once installed, you’ll notice how the engine settles into a smooth rhythm, free of squeals and inconsistent loading. Plus, its marine-formulated construction stands up to heat, moisture, and long hours of run time—reducing the need for frequent replacements and helping keep your maintenance routine simple.

Why Buy OEM

Choosing the correct belt isn’t just about convenience—it’s about protecting your engine. An OEM part like this one gives you reliable material quality, accurate sizing, and proven durability under real-world boating conditions. You’re not gambling on the hardness of the rubber, the precision of the grooves, or the long-term stretch. You’re getting exactly what MerCruiser intended for your engine, which translates to fewer headaches and better long-term value. When fellow boaters ask for advice, this is the kind of part you confidently recommend, because it just works the first time.

FAQ Section

Q1: Which Mercury engines does this serpentine belt fit?

It fits MerCruiser 496 Magnum engines within serial numbers 0M025000–0W309999.

Q2: What makes this different from aftermarket belts?

The sizing, material quality, and groove profile match the original equipment exactly, giving you smoother accessory operation and better long-term reliability.

Q3: How do I confirm it’s the correct belt?

Check your serial number, compare length, and reference your owner’s manual. If your engine is a 496 Magnum in the listed range, this belt is the correct replacement.

Q4: Is it suitable for saltwater and freshwater boats?

Yes, the composite material is designed for both environments.

Q5: Is installation simple?

Most boaters with basic tools can replace it themselves by relieving tension and routing the belt according to the engine diagram.