Mercury – 300 Hour Maintenance Kit | MerCruiser 5.0L & 5.7L MPI Alpha Series | OEM Service Components | 8M0147068

Overview

There’s a certain peace that settles in when you turn the key and your MerCruiser 5.0L or 5.7L MPI fires up exactly the way it should. No hesitation, no odd sounds—just that familiar, steady rumble that tells you your boat is ready for another long run. The Mercury 8M0147068 300 Hour Maintenance Kit is built for that moment. It’s designed for boaters who’d rather spend their weekends on open water than worrying about whether critical service items have been replaced on time. Everything you need is in one box, purpose-built to keep your Alpha-driven MPI engine running smooth, cool, and confident.

Key Features

• Complete 300-hour service kit for MerCruiser 5.0L and 5.7L MPI engines
• Includes oil filter, fuel filter, spark plugs, thermostat, thermostat gasket, serpentine belt, and gearcase drain seals
• Filters feature high internal pleat counts for superior contaminant control
• Electroplated housings support long-term corrosion resistance
• Built to Mercury Marine’s strict OEM standards for durability and reliability

Engine & Boat Compatibility

• Fits MerCruiser 5.0L and 5.7L MPI engines made by General Motors
• Compatible with Alpha sterndrives (2002 and newer)
• Ideal for sport boats, runabouts, family cruisers, bowriders, and fishing boats using these popular MPI powerplants

Performance & Practical Benefits

A 300-hour service isn’t just a maintenance chore—it’s what keeps your engine feeling tight, responsive, and trustworthy when you push the throttle forward. Fresh spark plugs restore crisp ignition under load, which you’ll notice during hole shots or when cruising at midrange speeds. A new thermostat and gasket ensure the engine maintains a steady temperature, preventing hot spots and maintaining peak fuel efficiency.

The serpentine belt replacement is one of those upgrades you truly appreciate on the water. A fresh belt eliminates slipping, squealing, or unexpected accessory failures. Meanwhile, the included filters handle the invisible but important work—keeping debris and moisture out of the engine and fuel system, so your boat runs smoother with every outing.

Every component fits exactly as intended—tight, secure, and without the slightest modification. With OEM parts, you don’t wrestle with sizing or questionable materials. You simply install, torque down, and get back on the water.

Why Buy OEM

Mercury builds these kits around the engines they designed, so every piece matches factory specifications. That means reliable fit, fewer surprises during installation, and a service life you can count on. Aftermarket parts may look similar, but they don’t offer the same long-term dependability, especially in corrosive marine environments. Using genuine Mercury components protects your investment, improves engine longevity, and reduces the chance of midseason breakdowns.

FAQ

Q1: Which engines does this kit fit?

This kit fits MerCruiser 5.0L and 5.7L MPI engines paired with Alpha sterndrives, model year 2002 and newer.

Q2: How is this better than aftermarket kits?

OEM Mercury parts match factory specs for perfect fit and long-term reliability—something aftermarket rarely guarantees.

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

If your setup is a 5.0L or 5.7L MPI with an Alpha drive, this is the correct 300-hour service kit.

Q4: Is it suitable for all water types?

Yes—every component is engineered for both saltwater and freshwater environments.

Q5: Is installation approachable for most owners?

If you’re comfortable with standard maintenance, this kit installs cleanly with everyday tools.