MERCURY 859619T04 Outboard Optimax Pro Flywheel Wheel 3.0L

( Manufacturer Part Number: 859619T04 ), ( Part Type: Flywheel Wheel )

Review MERCURY Outboard Optimax Pro Flywheel Assy 3.0l Fly Wheel fits 250 XS

The **Mercury 250 HP Optimax Pro-XS Outboard (Model 859619T04)** is a cutting-edge marine propulsion system engineered for performance, efficiency, and uncompromising reliability, making it an ideal choice for high-speed fishing boats, sportfishing vessels, and performance cruisers. This advanced outboard features Mercury s **3.0L Flywheel Housing**, a design innovation that enhances power delivery, reduces vibration, and improves overall smoothness during operation. The **Optimax Pro-XS** platform integrates Mercury s proprietary **Direct Drive** technology, eliminating the need for a traditional driveshaft and gearcase, which not only simplifies the mechanical layout but also reduces weight and maintenance requirements. This direct-drive system delivers instant torque and a seamless power curve, allowing for effortless acceleration and superior handling at both low and high speeds.

Under the hood, the **250 HP E-TEC engine** (Electronically-Controlled Technology) powers this outboard, combining a high-performance **4-stroke, liquid-cooled, V6 configuration** with Mercury s **SmartThrottle** and **SmartCraft** systems. These intelligent controls optimize fuel efficiency, throttle response, and engine protection, adapting in real-time to varying load conditions, water depth, and environmental factors. The **E-TEC engine** also incorporates advanced emissions technology, ensuring compliance with stringent marine regulations while maintaining peak performance. With a **5-blade, high-efficiency propeller**, the Optimax Pro-XS maximizes thrust and reduces cavitation, providing exceptional speed and maneuverability even in rough or shallow waters.

Designed with the modern angler and boater in mind, this outboard features a **sleek, aerodynamic cowling** that not only enhances aesthetics but also improves aerodynamics for reduced drag and better fuel economy. The **Pro-XS platform** includes a **steering wheel with integrated controls**, allowing for easy access to essential functions like throttle, trim, and shift, all while maintaining a clean, minimalist cockpit layout. The **trim and tilt system** is both precise and responsive, enabling quick adjustments for optimal performance in various conditions, whether you're planing across open water or cruising at low speeds in tight spaces.

For those who demand the latest in marine technology, the **Optimax Pro-XS** is compatible with Mercury s **SmartCraft App**, which provides real-time diagnostics, engine monitoring, and remote control capabilities via a smartphone or tablet. This connectivity allows boaters to track performance metrics, receive maintenance alerts, and even start or stop the engine remotely, adding an extra layer of convenience and safety. Additionally, the **3.0L Flywheel Housing** not only improves power transfer but also contributes to a quieter operation, reducing noise levels for a more enjoyable experience on the water.

Built to withstand the demands of heavy-duty use, the **Optimax Pro-XS 250 HP** is constructed with high-grade materials, including **aluminum alloy components** and **corrosion-resistant coatings**, ensuring durability and longevity even in saltwater environments. Mercury s reputation for reliability is further reinforced by the **extended warranty options** available, providing peace of mind for owners who invest in this premium outboard. Whether you're targeting big game, racing across open water, or simply enjoying a day of high-speed cruising, the **Mercury 859619T04 Optimax Pro-XS 250 HP** delivers a perfect blend of power, precision, and innovation setting a new standard for modern outboard performance.

The **Mercury 859619T04 Outboard (Optimax 250 Pro XS)** is a high-performance, 250 horsepower outboard designed for serious anglers and boaters who prioritize speed, reliability, and advanced features. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros**

1. **Power and Performance**

The 250 horsepower engine delivers strong acceleration and top-end speed, making it ideal for fishing boats, wakeboarders, and recreational use. The Optimax series is known for its smooth power delivery and responsiveness.

2. **Optimax Technology**

Mercury s Optimax platform integrates a direct-drive system, eliminating the need for a traditional gearcase. This reduces weight, improves fuel efficiency, and enhances reliability compared to traditional outboards. The 3.0L wheel (flywheel) is optimized for better power transfer and reduced vibration.

3. **Fuel Efficiency**

Direct-drive outboards like the Optimax are generally more fuel-efficient than traditional gearcase outboards, especially at cruising speeds. This can lead to lower operating costs over time.

4. **Lightweight and Compact Design**

The absence of a gearcase makes the engine lighter and more compact, which can improve handling and maneuverability on the water. This is particularly beneficial for smaller boats or those with weight restrictions.

5. **Advanced Electronics and Connectivity**

The Pro XS model often includes Mercury s **PowerBoost** (if applicable) and **Mercury Edge** connectivity features, allowing for remote monitoring, diagnostics, and integration with other marine electronics. This can enhance convenience and troubleshooting.

6. **Durability and Reliability**

Mercury outboards are built with marine-grade materials and undergo rigorous testing. The Optimax series is designed for longevity, with fewer moving parts than traditional outboards, which can reduce maintenance needs.

7. **Versatility**

- Fishing boats (e.g., bass boats, center consoles)

- Wakeboarders and watersports

- Small cruisers and day boats

- Some inflatable or lightweight rigid-hull inflatable boats (RHIBs)

8. **Ease of Installation**

The direct-drive design simplifies installation compared to traditional outboards, as there s no need to align a gearcase. This can make it easier for boat owners to swap or upgrade engines.

9. **Environmental Considerations**

Mercury has made strides in reducing emissions and improving fuel efficiency, which aligns with environmental regulations and sustainability goals for boaters.

10. **Resale Value**

Mercury outboards, especially newer models like the Optimax, tend to hold their value well due to their reputation for quality and performance.

---

### **Cons**

1. **Higher Upfront Cost**

The Optimax 250 Pro XS is more expensive than traditional 250 HP outboards with gearcases. The direct-drive technology and advanced features contribute to the higher price tag, which may be a barrier for budget-conscious buyers.

2. **Limited Gearcase Options**

Since the Optimax is direct-drive, it lacks the gear reduction options available in traditional outboards. This means you cannot adjust the gear ratio for different boat types or performance needs. For example, if you need a lower gear for towing or a higher gear for speed, you re limited to the fixed ratio of the Optimax.

3. **Maintenance and Repairs**

While the Optimax is designed to be low-maintenance, some mechanics may be less familiar with direct-drive outboards compared to traditional gearcase engines. This could lead to longer wait times for repairs or higher labor costs if you re not near a Mercury-authorized service center.

4. **Noise and Vibration**

Direct-drive outboards can sometimes produce more noise and vibration than gearcase outboards, especially at higher RPMs. While Mercury has worked to mitigate this, it may still be noticeable in quieter boats or during long trips.

5. **Compatibility Issues**

Not all boats are optimized for direct-drive outboards. Boats with specific weight or balance requirements may struggle with the power delivery of the Optimax, leading to handling issues or reduced performance. Always ensure your boat s specifications match the engine s capabilities.

6. **Limited Aftermarket Support**

Traditional outboards have a larger aftermarket support network for parts, upgrades, and modifications. The Optimax, being newer, may have fewer third-party options, which could be a drawback for boaters looking to customize their setup.

7. **Learning Curve**

Operating a direct-drive outboard may require some adjustment for boaters used to traditional gearcase engines. The power delivery can feel more immediate and less "geared," which might take time to get used to.

8. **Fuel and Oil Consumption**

While generally more fuel-efficient than traditional outboards, the Optimax still consumes fuel and oil. High-performance use (e.g., frequent revving or towing) can increase these costs over time.

9. **Potential for Overkill**

If your boat is small or lightweight, a 250 HP engine might be more power than needed, leading to excessive wear on the boat s structure or handling challenges. Always match the engine to your boat s size and intended use.

10. **Warranty and Service Considerations**

Mercury s warranty terms for Optimax engines may differ from traditional outboards. Ensure you understand the coverage and any potential out-of-pocket costs for repairs or replacements.

---

### **Conclusion**

The **Mercury 859619T04 Optimax 250 Pro XS** is a cutting-edge outboard that excels in performance, fuel efficiency, and innovation. Its direct-drive technology offers advantages in weight savings, reliability, and ease of use, making it an attractive choice for boaters who prioritize these features. However, the higher cost, lack of gearcase flexibility, and potential compatibility issues with certain boats are significant drawbacks.

- **Serious anglers** who want speed and efficiency without the bulk of a gearcase.

- **Watersports enthusiasts** (e.g., wakeboarding, tubing) who need consistent power delivery.

- **Boat owners** who prioritize modern technology, connectivity, and long-term reliability.

- **Boats** that are well-matched to the Optimax s power band (e.g., medium-sized fishing boats, cruisers).

If you re on a tight budget, prefer gearcase flexibility, or have a boat that isn t optimized for direct-drive power, a traditional 250 HP outboard might be a more practical choice.

---

### **Recommendation**

- You re looking for a high-performance, fuel-efficient outboard with modern technology.

- Your boat is well-suited for direct-drive power (e.g., medium to large fishing boats, cruisers, or watersports rigs).

- You value the simplicity and reliability of a direct-drive system.

- You re willing to invest in a premium engine for long-term use.

- You need gearcase flexibility for towing or specific performance requirements.

- Your boat is small or lightweight, and you re concerned about handling or structural stress.

- You prefer a lower upfront cost and are comfortable with traditional outboard maintenance.

- You re unsure about the long-term availability of parts or service support in your area.

Ultimately, the Optimax 250 Pro XS is a fantastic choice for boaters who want the best of modern marine engineering. Just ensure your boat and intended use align with its strengths. If in doubt, consult with a marine professional to confirm compatibility and performance expectations.

Details:

Please verify before purchasing. Engine SN 2B015722 These parts may fit other years and model's. This flywheel was removed from a 2013 Mercury 250 HP Optimax Pro XS, 6 cylinder, 2 stroke, direct fuel injected, 20 inch outboard.

part #: 859619t04 prices

• $175.00-$250.00

specifications ouboaen:

• for models: 250, Xs
• for makes: Mercury
• mpn: 859619t04
• part type: Flywheel Wheel

payments ouboaen:

• wallet: Paypal
• other
• credit card: Discover

returns ouboaen:

• paid by: Buyer
• time: 14 Days
• policy: Returns Accepted

offer ouboaen:

• started: April 10, 2026
• quantity: 1
• availability: In Stock
• sold: 0
• options: Ship-to-home

shipping ouboaen:

• class: Economy
• transit: 4-10 Days
• type: Fixed
• service: Economy
• cost: $0.00

seller ouboaen:

• rating: 99.9%
• city: Milledgeville, Georgia
• # reviews: 1123

general ouboaen:

• condition: Used
• Boat Parts > Outboard Engines Components > Other

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