SIERRA 18-6798 Motor 808282265120

( Brand: Sierra ), ( Manufacturer Part Number: 18-6798 ), ( Part Type: Motor ), ( UPC: 808282265120 )

Review SIERRA Trim Motor yamaha

The **Sierra 18-6798 Motor** is a high-performance, factory-approved replacement engine designed specifically for Yamaha outboard motors, offering a seamless upgrade for models ranging from 15 to 25 horsepower. Engineered with precision and built to exacting standards, this motor delivers exceptional reliability, efficiency, and power, making it an ideal choice for boaters seeking enhanced performance without compromising on durability. The 18-6798 features Yamaha s advanced **E-TEC (Electronic Throttle Control)** system, ensuring smooth, responsive acceleration and precise throttle control, whether you're cruising at leisure or tackling demanding fishing or watersports. Its compact yet robust design integrates seamlessly with existing Yamaha outboard mounts, ensuring compatibility with a wide range of vessels, from compact fishing boats to mid-sized cruisers. Under the hood, this motor is powered by a **4-stroke, air-cooled, single-cylinder engine** with a displacement of 18 horsepower, delivering a balanced blend of torque and efficiency while minimizing fuel consumption and emissions. The engine s **fuel-injected system** ensures optimal combustion, reducing carbon buildup and improving overall performance, while its **automatic choke** simplifies startup in varying conditions. Built to withstand the rigors of marine environments, the 18-6798 is constructed from high-grade materials, including corrosion-resistant components and a durable aluminum housing, which helps protect against saltwater corrosion a common challenge for marine engines. The motor also incorporates Yamaha s **Quiet Drive** technology, reducing noise levels for a quieter, more enjoyable boating experience. Whether you're upgrading for better fuel economy, increased power, or simply a more reliable engine, the Sierra 18-6798 Motor offers a premium solution that maintains Yamaha s reputation for quality and innovation. With its easy installation process thanks to the factory-matched design and long-term durability, this motor is a smart investment for boaters who demand performance without the hassle.

### **Pros and Cons of buying a Sierra 18-6798 Motor (Yamaha Engine)**

1. **Reliability and Brand Reputation** Yamaha is a well-known manufacturer of durable outboard motors, known for consistent performance and long-term reliability. The 6798cc engine is part of Yamaha s proven lineup, often favored for its smooth operation and strong aftermarket support.

2. **Power and Performance** The 6798cc engine delivers substantial horsepower (typically around 250 300 HP, depending on model year and trim), making it suitable for medium to large boats (18 25 feet). It provides strong acceleration and cruising speed, ideal for fishing, cruising, or watersports.

3. **Fuel Efficiency** Compared to larger outboards, the 6798cc offers a balance between power and fuel consumption. It s more efficient than high-horsepower engines while still providing ample thrust for most recreational and light commercial applications.

4. **Durability and Build Quality** Yamaha engines are built with robust materials and precision engineering. The 6798cc model is designed for heavy-duty use, with features like corrosion-resistant coatings, reinforced components, and reliable cooling systems.

5. **Aftermarket and Service Support** Yamaha has a vast network of dealers and service centers worldwide. Parts are widely available, and mechanics are familiar with troubleshooting common issues. The engine also benefits from a strong aftermarket, including upgrades like exhaust systems, performance chips, and fuel injection tuning.

6. **Lower Operating Costs (Compared to Larger Engines)** While not as fuel-efficient as smaller outboards, the 6798cc is more economical than 300 HP engines. Maintenance costs are reasonable, though regular upkeep (oil changes, spark plugs, etc.) is essential to prevent major repairs.

7. **Versatility** The engine can be paired with a variety of boat types, including center console fishing boats, cruisers, and even some small commercial vessels. Its mid-range power makes it adaptable to different applications.

8. **Quiet Operation** Yamaha engines are generally quieter than some competitors, which can be a plus for long cruises or in noise-sensitive areas.

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1. **Age and Obsolescence** The 6798cc engine is an older model (originally introduced in the late 2000s/early 2010s). While still reliable, it lacks the latest fuel efficiency, emissions compliance (e.g., EPA Tier 3/4 standards), and technological advancements found in newer Yamaha engines (e.g., 200 HP models with direct injection or electric start).

2. **Higher Fuel Consumption Than Modern Alternatives** Newer Yamaha engines (e.g., 200 300 HP models) are more fuel-efficient due to improved fuel injection systems and aerodynamics. The 6798cc may burn more gas, increasing operating costs over time.

3. **Potential for Higher Maintenance Costs** Older engines can develop wear in critical components (e.g., pistons, rods, or water pumps) over time. While well-maintained units may last decades, the risk of major repairs (e.g., engine rebuilds) increases with age.

4. **Limited Warranty Coverage** If purchasing a used engine, the original warranty (if any) may have expired. Newer engines typically come with extended warranties (e.g., 5-year outboard warranty), which provide peace of mind.

5. **Resale Value Depreciation** Like all boats and engines, the 6798cc loses value over time. If you plan to sell later, a newer engine (even a slightly smaller one) may hold its value better.

6. **Emissions and Regulations** Older engines may not meet current emissions standards in some regions, requiring modifications or limiting where the boat can be operated. Newer Yamaha models comply with stricter EPA/CSA regulations.

7. **Weight and Size** The 6798cc is a heavy engine (typically 300 400 lbs depending on trim), which can be challenging to handle during installation or maintenance. Larger boats may struggle with weight distribution.

- **Water pump failures** (common in older Yamaha outboards).

- **Exhaust manifold leaks** (due to corrosion or wear).

- **Fuel system clogs** (if not properly maintained).

- **Electrical gremlins** (e.g., starter motor or ignition issues).

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### **Conclusion**

The Sierra 18-6798 Yamaha engine is a solid choice for those seeking a **reliable, mid-power outboard** for medium-sized boats. It excels in **durability, performance, and aftermarket support**, making it a practical option for fishing, cruising, or light commercial use. However, its **age, fuel inefficiency, and potential for higher long-term maintenance costs** are significant drawbacks, especially compared to newer Yamaha models.

If you prioritize **proven reliability, lower upfront cost, and don t mind occasional maintenance**, the 6798cc is a great used engine. But if you want **better fuel economy, longer warranty coverage, and compliance with modern emissions standards**, investing in a newer Yamaha (e.g., 200 250 HP) may be more advantageous.

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### **Recommendation**

- You need a **powerful but affordable** engine for a boat under 25 feet.

- You re comfortable with **regular maintenance** and potential future repairs.

- You prefer a **proven, high-reliability** engine with strong aftermarket support.

- You re on a **tight budget** and can find a well-documented, low-hour used unit.

- You want **better fuel efficiency** and lower operating costs.

- You prefer **extended warranty coverage** and compliance with current emissions laws.

- You plan to **keep the boat long-term** and want to avoid obsolescence.

- You re open to **slightly higher upfront costs** for long-term savings.

**Final Verdict:** The Sierra 18-6798 Yamaha is a **great used engine** for the right buyer one who values reliability over cutting-edge technology. However, if budget allows, a newer Yamaha model will offer **better efficiency, longevity, and peace of mind**. Always inspect the engine thoroughly (service history, leaks, corrosion) before purchasing, regardless of brand or model.

Details:

Fits: F2 F225 2004-06, F250 2005-06, LF2 LF225, LF250, LZ2 LZ225, LZ250 2004-06 Replaces: 69J-43880-00- 60V-43880-00-00.

part #: 186798 prices

• $202.44-$284.97

specifications ignitionstartin:

• for makes: Yamaha
• brand: Sierra
• mpn: 18-6798
• part type: Motor
• upc: 808282265120

shipping ignitionstartin:

• type: Calculated
• carrier: USPS, FedEx
• transit: 5-12 Days
• class: Standard, Expedited
• service: USPS Ground Advantage, USPS Priority Mail, FedEx Ground / FedEx Home Delivery
• cost: $19.35

offer ignitionstartin:

• quantity: 10
• availability: In Stock
• sold: 0
• started: March 20, 2026
• options: Ship-to-home

returns ignitionstartin:

• time: 30 Days
• paid by: Seller
• policy: Returns Accepted

payments ignitionstartin:

• other
• wallet: Google-pay
• credit card: Discover

general ignitionstartin:

• condition: New
• Boat Parts > Inboard Engines Components > Ignition Starting Systems

seller ignitionstartin:

• city: Freeport, New York
• # reviews: 3740
• rating: 99.2%

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