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 the kit seasoned boaters keep on hand because it bundles everything you need for a major service interval—no scrambling, no guesswork, just genuine Mercury components built to protect your investment.

Key Features

• Complete 300-hour service kit for 4.3L MPI Bravo sterndrive engines
• Includes oil filter, fuel filter, spark plugs, thermostat, thermostat gasket, serpentine belt, gearcase drain seals, IAC air filter, and seawater pump impeller kit
• High-pleat, premium filtration components for maximum protection
• Electroplated housings and marine-rated materials for corrosion resistance
• All parts engineered to Mercury Marine OEM standards

Engine & Boat Compatibility

• Fits MerCruiser 4.3L MPI engines built by General Motors
• Designed for engines paired with Bravo sterndrives
• Compatible with model years 2002 and newer
• Ideal for runabouts, sport boats, family cruisers, and weekend fishing vessels relying on the 4.3L/Bravo combination

Performance & Practical Benefits

A 300-hour service is one of those milestones that separates “good enough” maintenance from the kind that keeps an engine running like new. This kit revives performance across the entire system. The new spark plugs restore crisp, confident ignition. A fresh serpentine belt means smoother accessory operation with less strain when you throttle up. The IAC air filter helps refine idle quality, making low-speed maneuvering more predictable and less choppy.

One standout addition in this kit is the seawater pump impeller, a critical piece for Bravo-driven boats. A strong impeller ensures steady cooling water flow—something you’ll feel in lower engine temps and reliable performance on long runs. The new fuel and oil filters eliminate debris and water, tightening up fuel delivery and protecting internal components from unnecessary wear.

Everything in this kit is chosen specifically for how the 4.3L MPI and Bravo system behaves under real-world use: heat, vibration, long hours, stop-and-go cruising, and even the hard pulls that come with tow sports. When you replace these parts as a set, you give your engine a clean slate—one you’ll feel the moment it comes back to life.

Why Buy OEM

There’s value in knowing the parts you’re installing aren’t “close enough,” but correct in every dimension. Mercury’s OEM components are built for exact fit and tested under the same demands as factory engines. That means no premature wear, no questionable seals, and no surprises halfway through your boating season. Aftermarket kits often mix materials or cut corners on filtration, and that gamble rarely pays off over time. With OEM, you’re protecting your engine the way Mercury intended—reliably, consistently, and affordably in the long run.

FAQ

Q1: Which engines does this kit fit?

It fits MerCruiser 4.3L MPI engines with Bravo sterndrives, model year 2002 and newer.

Q2: What makes it better than aftermarket kits?

OEM parts match Mercury’s exact engineering standards—better fit, better reliability, and proven long-term durability.

Q3: How do I confirm this is the right kit?

If your boat has a 4.3L MPI engine paired with a Bravo sterndrive, this is the correct 300-hour service kit.

Q4: Can it be used in freshwater and saltwater boats?

Absolutely. All components are built to withstand harsh marine environments.

Q5: Is installation easy?

Most owners familiar with routine maintenance find this kit straightforward. Every part replaces an existing component directly.