Sierra 18-79956
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Sierra 18-79956 Product Description
Enhance Your Yamaha Outboard's Fuel System Reliability
Upgrading or replacing the Vapor Separator Tank (VST) in your Yamaha outboard can make a world of difference in smooth operation, especially during long days on the water. This high-quality VST kit delivers the performance you need for models ranging from the F115 up to the powerful 350s, including FL250 and FL300 variants. Crafted with precision engineering, it tackles common fuel system issues like vapor lock and inconsistent delivery, ensuring your engine runs cleaner and more efficiently.
What sets this apart? It's built to withstand the harsh marine environment—corrosion-resistant materials and robust seals that hold up against saltwater exposure, ethanol-blended fuels, and constant vibration. Boat owners often report fewer hesitation problems at idle or under load after installation, translating to more confidence whether you're trolling for bass or pushing through choppy bays.
Perfect Fit for Your Yamaha Models
- F115 through F350 four-stroke outboards
- FL250 and FL300 configurations
- Direct replacement for OEM components, no modifications required
Before diving in, double-check your engine's serial number against Yamaha's model specs. This kit slots right into the existing setup, saving you time and frustration during servicing. It's a smart choice for preventative maintenance too, extending the life of your fuel injectors and high-pressure pump.
Step-by-Step Installation Insights
Swapping out a VST isn't overly complex if you're handy with tools, but attention to detail prevents leaks or air ingress. Start by relieving fuel pressure—disconnect the battery, clamp the fuel line, and remove the VST assembly. Clean the mounting area thoroughly to avoid debris contamination.
- Transfer any reusable fittings or sensors from the old unit.
- Install new O-rings and gaskets dry for best sealing.
- Prime the system by cycling the key before firing up—listen for the fuel pump whine without leaks.
- Torque bolts to spec (usually 5-7 ft-lbs) to avoid cracking plastic housings.
Pro tip: Work in a well-ventilated area and have absorbent pads ready for spills. Most installs take under two hours, and you'll notice improved throttle response immediately.
Long-Term Care for Peak Performance
To maximize longevity, inspect your VST annually or every 100 hours of operation. Look for cracks in the tank, brittle hoses, or filter clogs—common culprits in fuel starvation. Use fuel stabilizers during storage to combat ethanol separation, which can gum up the works.
Pair this with regular filter changes and water-separating bowls for a bulletproof fuel system. Owners who've made this swap often see reduced carbon buildup on pistons, leading to better fuel economy and lower emissions over time.
Frequently Asked Questions
What is a VST kit and why does my Yamaha outboard need one?
The Vapor Separator Tank (VST) separates fuel vapors from liquid fuel before it reaches the high-pressure pump, preventing vapor lock and lean conditions. It's essential for reliable starting and smooth running in modern four-strokes.
Is this kit compatible with all F115-F350 Yamaha models?
It fits F115 through F350, plus FL250-300 variants. Always verify your engine's serial number for exact match, as minor variations exist across years.
How do I know if my VST is failing?
Signs include hard starting, stumbling at low RPMs, or a whining fuel pump that doesn't quiet down. Black smoke or misfires under load are red flags too.
Can I install this myself without special tools?
Yes, basic wrenches, a fuel line clamp, and torque wrench suffice. No Yamaha-specific tools needed, but a service manual helps with torque specs.
Does this kit handle ethanol fuels?
Absolutely—materials are ethanol-resistant, reducing swelling or degradation common with older OEM parts.
Will this improve my outboard's performance?
It restores factory fuel delivery, often improving throttle response and idle stability. Not a power mod, but it prevents power-robbing issues.
How often should I replace the VST?
Every 3-5 years or 300-500 hours, depending on fuel quality and usage. Proactive replacement beats a breakdown on the water.
Save $22 when you buy the Sierra 18-79956 for only $85 from NVN Marine! Same day shipping before 3pm.
Sierra 18-79956 Technical Specifications
| Type: | |
|---|---|
| Vendor: |
Sierra Engine Parts |
| Weight: |
0.04 lb |
Sierra 18-79956 User Reviews
Sierra 18-79956 Shipping & Return
| Shipping Weight: |
0.04 lb |
|---|---|
| Box Sizes: |
2.00 (h) x 4.00 (w) x 4.00 (l) |
| Cubic Feet: |
32.0 |
| Returnable: |
Yes |
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