Mercury – Fuel Line Assembly | Fuel System | Gray Low-Permeation Hose | 8M0079963

Overview

Every boater knows that the fuel system is something you want working perfectly every single time — no drama, no guesswork, no surprises. And it often starts with that simple squeeze of the primer bulb. When it firms up with smooth, steady pressure, there’s a quiet confidence that settles in. The Mercury Fuel Line Assembly 8M0079963 is built to deliver that same dependable feeling day after day. Whether you’re easing out early in the morning or navigating back through a light chop, this assembly keeps your fuel moving clean and consistent so the engine responds exactly when you need it to.

Key Features

• Five-sixteenth-inch inside diameter hose for steady, reliable fuel flow
• Low-permeation hose construction helps reduce evaporation and gasoline odor
• Mercury-designed primer bulb provides firm, predictable priming pressure
• Heat-reflective gray exterior helps reduce the chance of vapor lock
• Flexible, marine-grade hose built to withstand long-term exposure to fuel, sun, and weather
• Compatible with a range of tank and engine connector types
• Suitable for portable tanks, permanent systems, and custom rigging layouts

Engine & Boat Compatibility

• Fits Mercury and Mariner outboards that use universal five-sixteenth-inch fuel lines
• Ideal for small to mid-range horsepower engines across many production years
• Works well on runabouts, skiffs, aluminum fishing boats, pontoons, tenders, and inflatable boats
• Adapts easily to different fuel tank styles once paired with the correct connectors

Performance & Practical Benefits

You can feel the difference right away. The primer bulb firms up cleanly, without that spongy or uneven feel that cheaper assemblies often have. It gives you instant feedback that fuel is moving properly through the system. The hose itself routes smoothly through tight spaces, bends naturally around corners, and resists collapsing or kinking — a key detail when the boat shifts in chop or passengers move around the deck.

On warmer days, the gray exterior coating reflects heat instead of absorbing it, helping keep fuel temperatures more stable and reducing the chances of vapor lock during longer runs. The low-permeation materials not only help preserve fuel quality but also lessen the gasoline smell that can build up when the boat is stored under a cover or in a shed. Over the long term, the hose stays flexible instead of stiffening or cracking, and the primer bulb maintains its reliable feel season after season. All of this translates into smoother starts, cleaner idle, and fewer mid-season fuel headaches.

Why Buy OEM

Fuel delivery isn’t something to compromise on. Mercury Marine engineers every detail — from the hose blend to the internal valves of the primer bulb — to meet the demands of real boating conditions. Aftermarket versions may look similar, but they rarely match Mercury’s long-term durability, priming strength, or consistent fit. Choosing OEM means proper alignment with your engine, dependable operation, and peace of mind that your fuel system is built to Mercury’s standards. It’s the practical, no-nonsense choice for boaters who want reliability above all else.

FAQ

Q1: Which engines does the 8M0079963 Fuel Line Assembly fit?

It fits Mercury and Mariner outboards using a universal five-sixteenth-inch fuel line, once matched with the correct connector types for your tank and engine.

Q2: Why choose this instead of an aftermarket option?

Mercury’s engineering provides stronger priming, longer hose life, and more consistent fuel delivery over time.

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

Check your hose diameter (five-sixteenth-inch) and identify your connector styles. With the proper fittings, this assembly is typically a direct match.

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

Yes. The materials are designed for long-term dependability in either environment.

Q5: Is the installation process straightforward?

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