Sierra 18-2861-1
Shipping (3PM)
Within 30 days
Sierra 18-2861-1 Product Description
Enhance Your Outboard's Performance with Reliable Exhaust Gaskets
When maintaining a Johnson or Evinrude outboard engine, one small component can make a big difference in reliability and efficiency: the exhaust gasket. This precision-engineered part creates a tight seal between the exhaust manifold and cylinder head, preventing leaks that could lead to water intrusion, corrosion, or reduced power. Designed as a direct replacement for OMC part 311121, it ensures your engine runs smoothly even under demanding marine conditions.
Crafted from high-quality composite materials, this gasket resists heat, pressure, and the harsh marine environment, offering superior durability over stock options. Boaters trust it for its consistent performance during long outings, whether you're trolling for walleye or pushing through rough waves.
Perfect Fit for Popular OMC V4 and V6 Engines
This gasket kit is tailored for a range of OMC-powered outboards, including select Johnson and Evinrude models from the V4 and V6 series. It matches the exact specifications of the original OMC 311121, ensuring bolt-on compatibility without modifications. Common applications include engines from the late 1970s through the 1990s, where exhaust manifold sealing is critical for optimal cooling and exhaust flow.
- Direct OEM replacement for hassle-free upgrades
- Kit includes two gaskets for complete manifold coverage
- Ideal for routine maintenance or rebuild projects
Simple Installation Steps for DIY Mechanics
Replacing exhaust gaskets is a straightforward job that most boat owners can tackle in an afternoon. Start by draining the cooling system and removing the exhaust manifold. Clean mating surfaces thoroughly to remove old gasket residue or carbon buildup—use a plastic scraper to avoid scratches. Position the new gaskets, ensuring proper alignment with bolt holes, then torque the manifold bolts to factory specs (typically 15-20 ft-lbs in a crisscross pattern). A thin layer of high-temp sealant on the edges can enhance longevity in high-vibration setups.
Pro tip: Inspect the manifold ports and cylinder head for warping during installation. A flat, mirror-like surface is key to a leak-free seal, extending the life of your powerhead.
Why Upgrade to Aftermarket Excellence
Choosing quality aftermarket parts like this gasket means balancing performance, affordability, and peace of mind. Inferior gaskets can blow out under heat cycles, leading to overheating or hydrolock—costly issues on the water. This option delivers OEM-level sealing with enhanced material resilience, reducing downtime and maintenance frequency.
Long-Term Engine Health Tips
To maximize the gasket's lifespan:
- Monitor exhaust for blue smoke or unusual noises, early signs of seal failure
- Flush the engine after saltwater use to prevent corrosion
- Replace during every powerhead service (every 300-500 hours)
- Pair with fresh coolant and manifold hardware for best results
Boat owners report fewer overheating episodes and smoother idling after installation, proving its value in real-world use.
Frequently Asked Questions
What engines is the Sierra 18-2861-1 gasket compatible with?
It fits select OMC Johnson and Evinrude V4 and V6 outboards as a direct replacement for OMC 311121. Verify your engine model for exact fitment.
Does this gasket kit include two pieces?
Yes, the kit provides two exhaust gaskets, enough for both sides of the manifold on applicable engines.
Is special sealant required for installation?
Not mandatory, but applying a thin layer of high-temperature RTV sealant on the outer edges can improve sealing in high-vibration environments.
How do I know if my exhaust gasket needs replacement?
Look for exhaust leaks, water in the oil, overheating, or white exhaust smoke. Regular inspection during tune-ups catches issues early.
Can I install this gasket myself?
Absolutely—it's a beginner-friendly job with basic tools. Remove the manifold, clean surfaces, align the gasket, and torque bolts evenly.
What's the material composition of this gasket?
Multi-layer steel reinforced composite for superior heat resistance, compression, and durability in marine applications.
Will this gasket prevent water intrusion?
Yes, a proper seal blocks cooling water from entering the exhaust ports, protecting against hydrolock and corrosion.
Save $8 when you buy the Sierra 18-2861-1 for only $4 from NVN Marine! Same day shipping before 3pm.
Sierra 18-2861-1 Technical Specifications
| Type: | |
|---|---|
| Vendor: |
Sierra Engine Parts |
| Weight: |
0.06 lb |
Sierra 18-2861-1 User Reviews
Sierra 18-2861-1 Shipping & Return
| Shipping Weight: |
0.06 lb |
|---|---|
| Box Sizes: |
1.00 (h) x 6.00 (w) x 7.00 (l) |
| Cubic Feet: |
42.0 |
| Returnable: |
Yes |
For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.