Mercury – 300 Hour Maintenance Kit | MerCruiser 4.3L MPI Alpha Series | OEM Service Components | 8M0147064

Overview

There’s a certain comfort that comes from knowing your engine is ready for whatever the water throws your way. When you run a MerCruiser 4.3L MPI with an Alpha sterndrive, you expect smooth throttle response, steady cooling, and the kind of reliability that lets you explore a little farther each time. The Mercury 8M0147064 300 Hour Maintenance Kit keeps that trust alive. It’s the kit you reach for when you’d rather enjoy your season than worry about preventable breakdowns. Everything inside is purpose-built, familiar, and designed to keep your engine running the way it did on its best day.

Key Features

• Complete 300-hour service kit for MerCruiser 4.3L MPI engines
• Includes oil filter, fuel filter, gearcase drain seals, spark plugs, thermostat, thermostat gasket, serpentine belt, and IAC air filter
• Premium filtration components with high pleat counts
• Heavy-duty electroplated housings for corrosion resistance
• Assembled to meet Mercury Marine OEM specifications

Engine & Boat Compatibility

• Fits MerCruiser 4.3L MPI engines made by General Motors
• For engines paired with an Alpha sterndrive
• Compatible with model years 2002 and newer
• Perfect for runabouts, bowriders, family cruisers, sport boats, and fishing boats using the 4.3L MPI package

Performance & Practical Benefits

A 300-hour service isn’t just another item on the checklist—it’s a reset button for your engine’s dependability. Each part in this kit plays a role you’ll feel out on the water. The new spark plugs bring back crisp ignition. The IAC air filter and fuel filter help the engine breathe and burn clean, giving you steadier idle and smoother acceleration. Fresh gearcase seals keep the oil where it belongs, fighting off the wear that comes with long days spent at various speeds.

The heavy-duty thermostat and gasket restore proper temperature regulation, meaning the engine runs cooler and more consistent when you’re pushing through chop or easing into the no-wake zone. And because every component is selected specifically for the 4.3L MPI/Alpha pairing, you don’t deal with the uncertainty of mismatched aftermarket pieces. Everything fits tight. Everything works right. It’s maintenance made simple so your time can be spent boating—not wrenching.

Why Buy OEM

When it comes to service intervals this important, OEM isn’t a luxury—it’s your best protection. Mercury designs these parts around the exact operating demands of the 4.3L MPI engine. The fit is precise, the filtration is proven, and the materials are chosen specifically to handle marine heat, vibration, and corrosion. Aftermarket kits often cut corners on filter quality and seal durability, which can create new problems instead of preventing them. With this kit, you know you’re installing the same caliber of components Mercury trusts on every factory build.

If you want long engine life, factory reliability, and zero guesswork, OEM is the only real choice.

FAQ

Q1: Which engines does this maintenance kit fit?

It fits MerCruiser 4.3L MPI engines with Alpha sterndrives from 2002 and newer.

Q2: Why choose this over aftermarket kits?

OEM components match the exact specs Mercury designed for your engine—better fit, better longevity, better reliability.

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

Check that your engine is a 4.3L MPI paired with an Alpha sterndrive and falls within the 2002+ model range.

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

Yes—every component is built to withstand the corrosive challenges of either environment.

Q5: Is installation straightforward?

Most boat owners find the kit intuitive to use. Each part replaces a factory component directly, with no modification needed.