Mercury – Fuel Line Assembly | Fuel System | Gray Low-Permeation Hose | 8M0078014

Overview

There’s a quiet confidence that comes from a fuel system that behaves exactly the way it should. One squeeze of the primer bulb, that steady firmness rising in your hand, and you know the engine is going to fire right up. No hesitation, no guessing — just dependable response every time you leave the dock. The Mercury Fuel Line Assembly 8M0078014 is built around that feeling. Whether you’re drifting across glass-calm water at sunrise or pushing through an afternoon breeze on the ride home, it keeps fuel flowing smooth and consistent so you can stay present in the moments that matter.

Key Features

• Five-sixteenth-inch inside diameter hose for reliable, even fuel flow
• Low-permeation hose construction helps maintain fuel freshness and reduce odor
• Mercury-engineered primer bulb provides firm, predictable priming
• Gray outer coating reflects heat to minimize vapor-lock risk
• Flexible, durable marine-grade hose designed for long-term use
• Compatible with a variety of tank and engine connector styles
• Ideal for portable tanks, integrated systems, and custom rigging layouts

Engine & Boat Compatibility

• Fits Mercury and Mariner outboards using universal five-sixteenth-inch fuel lines
• Works with small and mid-range outboards across many model years
• Great for pontoons, fishing boats, skiffs, runabouts, aluminum rigs, tenders, and inflatables
• Adapts cleanly to different tank types when paired with the correct connectors

Performance & Practical Benefits

The primer bulb gives you the story right away — it firms up clean and steady, letting you know fuel is moving exactly the way it should. Once installed, the hose routes easily through tight rigging paths, bending naturally around corners without collapsing or kinking. That flexibility keeps the flow smooth when the boat shifts under load or bounces through chop.

On hot days when the sun reflects off the deck, the gray coating helps deflect heat, reducing the chances of vapor lock and keeping fuel temperatures more stable. The low-permeation material limits fuel odor and helps fuel last longer, especially helpful if the boat is stored inside or under a cover. Season after season, the hose holds its flexibility instead of cracking or turning rigid, and the primer bulb stays responsive — giving you that same reliable feel every time you prime it. The result is smoother starts, steadier idle, and fewer mid-season headaches.

Why Buy OEM

Genuine Mercury Marine parts are designed to meet the same engineering standards as the outboards they support. From hose composition to primer bulb valves, everything is tuned for the demands of real-world boating. Aftermarket fuel lines might look similar, but they rarely match Mercury’s durability, priming strength, or long-term consistency. Choosing OEM means better fit, cleaner operation, and fewer surprises. It’s the kind of practical decision experienced boaters make because they’d rather spend time on the water — not troubleshooting their fuel system.

FAQ

Q1: Which engines does the 8M0078014 Fuel Line Assembly fit?

It fits Mercury and Mariner outboards using universal five-sixteenth-inch fuel lines and the appropriate connectors for your setup.

Q2: What makes this better than aftermarket versions?

Mercury’s engineering delivers stronger priming, tougher hose materials, and more consistent long-term performance.

Q3: How do I confirm it’s the right replacement?

Verify your system uses a five-sixteenth-inch hose and identify your connector types. With the correct fittings, this assembly is typically a direct match.

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

Yes. It’s designed for long-term durability in either environment.

Q5: Is installation straightforward?

Very. Add the correct connectors, route the hose neatly, secure it properly, and most boaters can install it with ease.