Mercury – Fuel Line Assembly | Fuel System | Gray Low-Permeation Hose | 8M0078013

Overview

There’s something reassuring about gear that does exactly what it’s supposed to do — especially when it’s part of your fuel system. One squeeze of the primer bulb, that smooth and steady pressure building in your hand, and you can already feel the engine waking up. No hesitation, no guessing. The Mercury Fuel Line Assembly 8M0078013 is built to deliver that familiar confidence every time you push off from the dock. Whether you’re slipping out for a quiet morning troll or cruising back through afternoon chop, it keeps fuel flowing cleanly and consistently so you can enjoy the water without worrying about the line that feeds your engine.

Key Features

• Five-sixteenth-inch inside diameter fuel line for dependable, consistent fuel flow
• Low-permeation construction helps maintain fuel freshness and reduce fumes
• Mercury-engineered primer bulb delivers firm, predictable priming pressure
• Gray outer coating reflects heat to lower vapor-lock risk
• Flexible, long-lasting marine-grade hose designed for real-world conditions
• Compatible with a variety of tank and engine connector styles
• Works for portable tanks, fixed systems, and custom rigging paths

Engine & Boat Compatibility

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

Performance & Practical Benefits

You’ll feel the quality immediately — the primer bulb firms up with smooth, even pressure, giving you instant reassurance that fuel is moving exactly the way it should. The hose routes easily through tight rigging tunnels and bends naturally around corners without collapsing. That flexibility helps keep the flow steady when the boat hits chop or passengers shift around.

On hot days, the gray coating does more than look good — it reflects heat and helps prevent vapor lock, keeping the fuel line cooler and more stable under load. The low-permeation design helps limit fuel odor and keeps fuel fresher over longer stretches, especially helpful if your boat is stored inside or under a cover. Over time, the hose resists cracking, stiffening, and sun-related wear, while the primer bulb stays responsive and firm. The result is reliable starting, smoother idle performance, and fewer fuel-related hiccups throughout the season.

Why Buy OEM

Genuine Mercury Marine parts aren’t just about brand name — they’re built to meet the same engineering standards as the outboards themselves. From the hose materials to the valves inside the primer bulb, every detail is tuned for predictable performance in real marine environments. Aftermarket fuel lines may look similar, but they rarely provide the same long-term durability or priming consistency. Choosing OEM means a secure fit, dependable operation, and fewer problems out on the water. It’s the smart choice for boaters who value reliability over shortcuts.

FAQ

Q1: Which engines does the 8M0078013 Fuel Line Assembly fit?

It fits Mercury and Mariner outboards using universal five-sixteenth-inch fuel lines and can be matched with the correct connectors for your setup.

Q2: What makes this better than aftermarket options?

Mercury’s engineering ensures stronger priming, better hose durability, and more consistent long-term fuel delivery.

Q3: How do I know if this is the right replacement?

Check your current hose diameter and connector types. If your system uses a five-sixteenth-inch line, this assembly is typically the right fit once paired with proper fittings.

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

Yes. It’s built for long-term performance in either environment.

Q5: Is installation straightforward for most boaters?

Very. Add the correct connectors, route the hose neatly, secure it properly, and installation is simple.