Mercury – 300 Hour Maintenance Kit | MerCruiser 3.0L MPI | OEM Service Components | 8M0147062

Overview

Anyone running a MerCruiser 3.0L MPI knows the engine’s charm: it’s straightforward, fuel-friendly, and consistently dependable. But even the most reliable powerplants need deep, thoughtful care every few hundred hours. The Mercury 8M0147062 300 Hour Maintenance Kit gathers every critical service item into one tidy package, giving you the confidence that your MPI engine will keep starting strong, idling clean, and pushing you across open water with that smooth, familiar rhythm. It’s the kind of routine maintenance that doesn’t just protect your investment—it makes every weekend run feel better, cleaner, and more secure.

Key Features

• Complete 300-hour service kit for 3.0L MPI MerCruiser engines
• Includes oil filter, fuel filter, gearcase drain seals, spark plugs, thermostat, thermostat gasket, V-belts, and an IAC air filter
• High-pleat oil and fuel filters ensure superior debris control
• Electroplated housings resist corrosion in harsh marine environments
• OEM-engineered components maintain factory performance and longevity

Engine & Boat Compatibility

• Fits MerCruiser 3.0L MPI engines built by General Motors (2008 and newer)
• Compatible with popular sterndrive layouts found in bowriders, runabouts, fishing boats, and light cruisers
• Suitable for single-engine and twin-engine configurations
• Designed for boats using Gen-based GM MPI systems

Performance & Practical Benefits

A proper 300-hour service restores the backbone of your engine’s health. The new spark plugs bring back crisp ignition, helping the engine fire with more confidence and consistency. The thermostat and gasket stabilize operating temperature, ensuring the MPI system delivers the smooth throttle response it’s known for. Clean oil and fuel filters keep impurities from slipping into the system, protecting injectors, bearings, and internal passages.

The addition of a fresh IAC air filter is a subtle but important upgrade—keeping idle control steady and predictable, especially during tight maneuvering around docks or slow cruising through the marina. Meanwhile, the new V-belts restore tension and eliminate the subtle squeaks or slippage that often creep in with age.

Altogether, this kit brings back that “tight and steady” feeling—the sensation of a healthy engine responding exactly the way it should.

Why Buy OEM

An MPI engine runs best when every component is speaking the same engineering language. That’s where OEM parts matter. Mercury’s filters, seals, thermostats, and belts are built to the exact tolerances the engine was designed around. Aftermarket alternatives may save a few dollars, but they rarely offer the same filtration efficiency, material hardness, or corrosion resistance—especially in saltwater.

With an OEM kit, you avoid surprises and protect the longevity of your investment. It’s the smarter choice for boaters who’d rather spend time on the water than troubleshooting avoidable failures.

FAQ

Q1: Which engines does this kit fit?

This kit is made for MerCruiser 3.0L MPI engines from 2008 and newer.

Q2: What makes it better than aftermarket kits?

OEM parts deliver exact fitment, better filtration, and proven durability in marine environments.

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

Match your engine’s year and model—if you have a 3.0L MPI (2008+), this is the correct option.

Q4: Is it suitable for saltwater boats?

Absolutely. Every component is designed for both freshwater and saltwater conditions.

Q5: Is installation manageable for most boat owners?

If you’re comfortable with routine maintenance, this kit installs cleanly and predictably.