Mercury – Fuel Line Assembly | Fuel System | Gray Low-Permeation Hose | 8M0078625

Overview

There’s something reassuring about equipment that responds exactly the way it should especially when it’s part of your fuel system. One smooth squeeze of the primer bulb, that firm rise in pressure, and you can feel the engine coming to life even before it turns over. It’s a small moment, but it sets the tone for the day, whether you’re slipping out for a sunrise drift or heading across open water with the family aboard. The Mercury Fuel Line Assembly 8M0078625 is built for that kind of confidence. It keeps fuel moving steady and clean, giving you one less thing to worry about and letting you sink into the rhythm of the water.

Key Features

• Five-sixteenth-inch inside diameter fuel line for smooth, reliable fuel delivery
• Low-permeation hose design helps preserve fuel quality and reduce gasoline odor
• Mercury-engineered primer bulb delivers strong, predictable priming
• Gray heat-reflective exterior helps lower the risk of vapor lock on warm days
• Flexible, marine-grade hose built for durability in harsh boating environments
• Compatible with a range of tank and engine connector styles
• Ideal for portable tanks, integrated systems, and custom rigging paths

Engine & Boat Compatibility.

• Fits Mercury and Mariner outboards using universal five-sixteenth-inch fuel lines
• Works well for small to mid-range horsepower engines across many model years
• Suitable for pontoons, aluminum fishing rigs, skiffs, runabouts, tenders, and inflatables
• Adapts to different fuel tank styles when paired with the correct fittings

Performance & Practical Benefits

You feel the quality right away. The primer bulb firms up quickly with a crisp, even response, giving you confidence that fuel is moving properly. The hose routes easily through tight rigging channels, bends around corners without collapsing, and maintains flow even when the boat rocks, shifts weight, or hits a choppy stretch. That flexibility makes a noticeable difference in keeping the engine fed consistently.

On hot days, the gray outer coating helps reflect heat and keep fuel temperatures stable — a subtle but important detail that reduces vapor-lock issues. The low-permeation hose also limits fuel smell and slows evaporation, which is especially helpful during storage or when the boat stays covered for long periods. Over time, the hose stays flexible instead of turning brittle, and the primer bulb keeps its firm, confident feel season after season. The result is smoother starts, steadier idle performance, and fewer fuel-related surprises in the middle of a trip.

Why Buy OEM

Fuel delivery isn’t something to gamble on. Genuine Mercury Marine parts are engineered to meet the same standards as the outboards they support, down to the materials inside the primer bulb. Aftermarket options may look similar, but they rarely match Mercury’s consistency, durability, or long-term performance. Choosing OEM means proper fitment, predictable fueling, and the peace of mind that you’re using a Mercury Marine part designed for your engine. It’s the practical, reliable choice for anyone who values smooth, trouble-free time on the water.

FAQ

Q1: Which engines does the 8M0078625 Fuel Line Assembly fit?

It fits Mercury and Mariner outboards that use a universal five-sixteenth-inch fuel line and the appropriate tank and engine connectors.

Q2: What makes this better than aftermarket alternatives?

Mercury’s engineering provides stronger priming, more durable hose materials, and more consistent long-term fuel flow.

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

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

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

Yes. It’s designed for dependable performance in either environment.

Q5: Is installation straightforward for most boaters?

Absolutely. Add the correct connectors, route the hose cleanly, secure it properly, and installation is simple.