Sierra 18-80011
Shipping (3PM)
Within 30 days
Sierra 18-80011 Product Description
Keeping your outboard motor running smoothly on the water starts with reliable fuel delivery. A worn fuel pump diaphragm can lead to erratic performance, hard starts, or complete breakdowns mid-trip. That's where the Sierra diaphragm set steps in as a straightforward, effective fix for marine enthusiasts who demand precision without the premium price tag.
Why Your Fuel Pump Diaphragm Matters More Than You Think
Imagine heading out for a weekend fishing charter only to have your engine sputter because fuel isn't pumping consistently. The diaphragm in your outboard's fuel pump acts like the heartbeat of the system—it flexes to draw fuel from the tank and push it to the carburetor or injectors. Over time, exposure to ethanol-laced fuels, heat, and constant vibration causes it to crack, harden, or swell, leading to leaks, vapor lock, or starvation.
Boat owners who've swapped in a fresh diaphragm set report crisper throttle response and fewer no-start mornings. It's not just a part; it's peace of mind for every outing, whether you're trailering to the lake or chasing billfish offshore.
Engineered for Marine Demands: Inside the Sierra Diaphragm Set
Crafted from durable, fuel-resistant neoprene and reinforced materials, this diaphragm set mirrors OEM specs but stands up tougher to modern fuels. Each kit includes the primary diaphragm, gaskets, and necessary seals for a complete refresh. Precision-cut edges ensure a bubble-free seal, preventing air intrusion that plagues lesser replacements.
- Exact-fit design: Slides right into popular outboard fuel pumps without modifications.
- Ethanol-compatible: Handles E10 and beyond, resisting the degradation that plagues older stock parts.
- Easy-access packaging: Organized components make assembly a breeze, even on the water if needed.
From weekend warriors to professional guides, this set has earned its stripes in salty environments and freshwater marinas alike.
Perfect Fit for Your Setup
Designed as a direct replacement for a range of Mercury and compatible outboards, this diaphragm set restores factory performance across 4-cylinder to V6 models. Common applications include 90-150 HP two-strokes and early four-strokes where mechanical fuel pumps rule. Always cross-check your engine's serial number against fitment charts from trusted marine resources to confirm—saving you time and frustration at the ramp.
Pro tip: Pair it with a fuel filter screen cleaning for a full system revival that maximizes horsepower and mileage.
DIY Installation: From Toolbox to Trailered in Under an Hour
No marine mechanic degree required. With basic tools—a screwdriver set, pliers, and fresh fuel line primer— you'll handle this refresh:
- Relieve system pressure by pinching the primer bulb and loosening the pump outlet hose.
- Remove the pump cover (usually four screws), inspect for debris, and extract the old diaphragm.
- Install the new set per orientation marks, torque cover screws evenly to avoid warping.
- Prime the system, check for leaks, and fire it up—smooth idle awaits.
Bonus: Do this annually during off-season storage to preempt failures. If you're wrenching on a twin-engine rig, budget extra time for symmetry.
"Swapped mine on a '98 115 Mercury last spring—night and day difference in hot-weather reliability." – Experienced angler feedback.
Long-Term Fuel System Mastery
Beyond the diaphragm, nurture your outboard's fuel heart with these habits:
- Switch to ethanol-free gas for storage or mix in stabilizer religiously.
- Flush lines with cleaner after salty runs to combat corrosion.
- Monitor pump arm travel—short strokes signal diaphragm wear early.
- Upgrade to non-collapsing hoses if yours are original equipment.
These tweaks extend pump life 2-3x, keeping you on plane instead of the hook truck.
Frequently Asked Questions
What engines is the Sierra fuel pump diaphragm set compatible with?
It's a direct fit for many Mercury outboards from 90-150 HP, including popular two-stroke models. Verify via your engine's parts diagram for exact matches.
How do I know if my fuel pump diaphragm needs replacing?
Signs include hard starting, loss of power under load, fuel leaks around the pump, or black smoke from unburnt fuel. A visual crack confirms it.
Can I use this with ethanol-blended fuels?
Yes, the materials are formulated for E10 and similar blends, offering better resistance than many OEM diaphragms.
Is installation difficult for beginners?
Not at all—basic tools and 30-45 minutes suffice. Follow the pump's access points, and it's straightforward.
How often should I replace the fuel pump diaphragm?
Every 2-3 years or 300 hours of use, especially with ethanol fuels. Proactive swaps prevent bigger issues.
Will this fix vapor lock issues?
Often yes—a fresh diaphragm improves sealing and pulse efficiency, reducing vapor buildup in hot conditions.
What's included in the kit?
Primary diaphragm, gaskets, and seals for a full pump service.
Save $4 when you buy the Sierra 18-80011 for only $18 from NVN Marine! Same day shipping before 3pm.
Sierra 18-80011 Technical Specifications
| Type: | |
|---|---|
| Vendor: |
Sierra Engine Parts |
| Weight: |
0.2 lb |
Sierra 18-80011 User Reviews
Sierra 18-80011 Shipping & Return
| Shipping Weight: |
0.2 lb |
|---|---|
| Box Sizes: |
6.00 (h) x 0.00 (w) x 6.00 (l) |
| Cubic Feet: |
0.0 |
| Returnable: |
Yes |
For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.