MERCURY 10-821301 Optimax Dfi Screw 90HP 10X45 T2

( Manufacturer Part Number: 10-821301 ), ( Part Type: Screw ), ( Country Of Origin: United States )

Review MERCURY 45 90hp Optimax Dfi Screw 10x45 T2 fits 2006

The **Mercury 45 HP Optimax DFi Outboard Motor (Model 10-821301-45, 2006, 90 HP)** is a high-performance, fuel-efficient marine engine designed to deliver exceptional power and reliability for both recreational and light-duty applications. Part of Mercury s acclaimed **Optimax** series, this **4-stroke, direct fuel-injected (DFi)** outboard combines cutting-edge technology with rugged durability, making it an ideal choice for boats ranging from mid-sized fishing vessels to performance cruisers. With a **10-inch shaft diameter and a 45-inch waterline length**, this motor strikes a perfect balance between compact maneuverability and robust power delivery, ensuring smooth operation in both calm waters and rougher conditions. The **90 HP** rating provides ample thrust for towing trailers, handling waves, or accelerating quickly while maintaining fuel efficiency thanks to Mercury s advanced **Direct Fuel Injection (DFi)** system, which optimizes combustion for cleaner, more efficient performance compared to traditional carbureted engines. This system not only reduces emissions but also enhances throttle response, allowing for precise control whether you re trolling for fish or cruising at high speeds.

Built with **Mercury s legendary reliability**, this 2006 model features a **cast aluminum crankcase** and a **forged crankshaft**, ensuring long-lasting durability even under demanding conditions. The **T2 trim tab** (10x45) is designed to improve stability and handling, reducing bow-rise and providing better control in waves, which is particularly beneficial for anglers or boaters who prioritize comfort and precision. The **4-stroke engine architecture** eliminates the need for frequent oil changes in the fuel system, reducing maintenance hassles while maintaining peak performance. Additionally, the **Optimax DFi** platform incorporates **Mercury s Power Trim II** system, allowing for effortless adjustments to the motor s angle for optimal speed, fuel efficiency, and maneuverability. Whether you re launching from a crowded ramp or navigating tight channels, this motor s **smooth, quiet operation** and **responsive throttle** make it a standout choice for those seeking a blend of power, efficiency, and ease of use.

For those who appreciate both performance and practicality, the **Mercury 45 HP Optimax DFi** is a well-rounded outboard that excels in versatility. Its **compact yet powerful design** makes it suitable for a variety of boat types, from small fishing boats to wakeboarders, while its **fuel-injected system** ensures consistent power delivery in all weather conditions. With proper maintenance, this engine retains its strength for years, making it a cost-effective investment for boaters who demand reliability without sacrificing performance. Whether you re an avid angler, a weekend cruiser, or someone who enjoys the thrill of high-speed runs, this **90 HP Mercury Optimax DFi** delivers the perfect fusion of technology, efficiency, and raw power to elevate your time on the water.

### **Pros and Cons of Buying a Mercury 10.0 821301 45 (2006, 90 HP, Optimax DFi, Screw Prop, 10x45, T2)**

1. **Reliable and Proven Engine** The Mercury 90 HP Optimax DFi engine is a well-established model known for durability and consistent performance. It is widely used in fishing boats, personal watercraft, and small cruisers, which means parts and support are readily available.

2. **Fuel Efficiency** The DFi (Direct Fuel Injection) system improves fuel efficiency compared to older carbureted engines, reducing fuel consumption and emissions. This can save money over time, especially for frequent users.

3. **Good Power-to-Weight Ratio** At 90 HP, this engine provides adequate power for small to medium-sized boats (typically 16 20 feet) without excessive fuel consumption. It is suitable for cruising, fishing, and light planing.

4. **Optimax Series Benefits** The Optimax line is designed for reliability and ease of maintenance. It often includes features like a simplified cooling system, easier access to components, and a reputation for longevity when properly maintained.

5. **Screw Propeller Compatibility** The 10x45 screw propeller is a standard size for this engine, offering a balance between speed and fuel efficiency. It works well for general boating purposes, including fishing and leisure cruising.

6. **Aftermarket Support** Mercury s Optimax engines have a large aftermarket following, meaning you can find replacement parts, upgrades (e.g., exhaust systems, throttle bodies), and tuning options relatively easily.

7. **Lower Operating Costs** Compared to larger or high-performance engines, the 90 HP Optimax is relatively inexpensive to run. Maintenance costs are moderate, and fuel consumption is reasonable for its class.

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

- Personal watercraft (PWCs) or small cruisers

- Tenders or utility boats

- Replacement for older, less efficient engines

9. **Ease of Maintenance** The DFi system is generally easier to maintain than carbureted engines, with fewer clogs and simpler adjustments. Regular oil changes and filter replacements are the primary maintenance tasks.

10. **Resale Value** Mercury engines, especially well-maintained Optimax models, hold their value reasonably well compared to some other brands. A properly cared-for 2006 engine may still have resale appeal.

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1. **Age of the Model (2006)** While the engine is not ancient, it is now over 15 years old. Newer models (e.g., Mercury s Verado or FourStroke engines) offer improved fuel efficiency, emissions compliance, and technology. Older engines may lack modern features like electronic throttle control or advanced diagnostics.

2. **Emissions Regulations** The 2006 model predates stricter emissions standards (e.g., EPA Tier 3 or California Air Resources Board regulations). While it likely meets its era s requirements, upgrading to a newer engine may be necessary if boating in areas with strict emissions laws.

3. **Potential for Wear and Tear** A 2006 engine may have accumulated some internal wear, especially if not well-maintained. Common issues to watch for include:

- Worn piston rings or cylinder walls

- Failed water pump or impeller

- Leaking seals or gaskets

- Carburetor or fuel system clogs (though DFi reduces this risk)

4. **Limited Warranty Coverage** Mercury s original warranty for this model would have expired long ago. Any repairs or replacements would be out-of-pocket unless you purchase an extended warranty or service contract.

5. **Fuel and Oil Requirements** Older engines may require specific fuel grades or additives to prevent gumming or varnish buildup. Using modern marine fuels (e.g., ethanol-blended gas) can sometimes cause issues if not properly treated.

6. **Propeller Matching** The 10x45 screw is a standard size, but if the boat s weight distribution or load changes, the propeller may not be optimal. Upgrading to a different pitch (e.g., 10x40 for more power or 10x50 for better towing) could improve performance.

7. **Noise and Vibration** Older engines can be noisier and vibrate more than newer models, which may affect comfort, especially in enclosed cabins.

8. **Parts Availability** While parts are still available, some specialized components (e.g., OEM gaskets, seals, or sensors) may become harder to find over time. Aftermarket parts are an option but may not always match OEM quality.

9. **Fuel Injection Reliability** While DFi is an improvement over carburetors, fuel injectors can clog or fail over time, requiring cleaning or replacement. This adds to maintenance costs.

10. **Upfront Cost vs. Newer Alternatives** Buying a used 2006 engine may be cheaper than a new or newer used engine (e.g., a 2015 Mercury FourStroke or Yamaha 400 series). If budget allows, a newer engine could offer better long-term reliability and efficiency.

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The **Mercury 90 HP Optimax DFi (2006)** is a solid, reliable choice for small to medium-sized boats, especially if you prioritize affordability, simplicity, and proven performance. It is well-suited for fishing, cruising, or light utility work where high speed is not a primary concern. However, its age means it may not meet modern emissions standards, could require more frequent maintenance, and lacks the efficiency and technology of newer engines.

If you are buying this engine for a boat where it will be the primary power source and you are prepared for potential wear, it can be a cost-effective solution. Conversely, if you want better fuel economy, lower emissions, or modern features, investing in a newer engine (even used) might be worth the extra cost.

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- You need a reliable, low-cost engine for a small boat (e.g., under 20 feet) where high performance is not critical.

- You are comfortable with basic maintenance and can inspect the engine thoroughly for wear before purchase.

- The boat s application (e.g., fishing, leisure cruising) does not require the latest technology or emissions compliance.

- You plan to keep the boat long-term and are okay with the engine s age.

- You want better fuel efficiency or emissions compliance (e.g., a newer Mercury FourStroke or Yamaha 400 series).

- The boat will see heavy use or require high performance (e.g., towing, speed).

- You prefer modern features like electronic throttle control or easier diagnostics.

- You are unsure about the engine s maintenance history and cannot verify its condition.

**Final Verdict:** This engine is a **good, budget-friendly option for casual boaters** who value reliability over cutting-edge technology. For those who want a more future-proof or efficient engine, exploring newer models (even used) may be justified. Always inspect the engine thoroughly, check maintenance records, and consider the boat s intended use before purchasing.

Details:

We operate in Central Standard Time. Recombine shipping on multiple items. Pleasured entire listing before buying or purchasing item. Mercury catalog 90-891837008.

They will however be in functioning and usable condition. Just because the part looks right does not mean that Otis. Keeping mind that if the listing is for a used part, it used part, so there may be some minor cosmetic damage scratches/scuffs. Parts off of a 2006 Mercury 90hp Optimax DFI 1.5L freshwater outboard motor, model 90EPLTO / 1090D73HY, serial 1B866406, 3-cylinder, 2-stroke, long shaft for 20 transoms, power head lost compression, Cylinder 1 - 90psi, 2 115psi, 3 120psi.

part #: 10821301 prices

• $7.65-$24.99

specifications ouboaen:

• for makes: Mercury
• for years: 2006
• mpn: 10-821301
• part type: Screw
• country of origin: United States

seller ouboaen:

• # reviews: 6044
• city: Melrose, Minnesota
• rating: 99.9%

offer ouboaen:

• started: May 13, 2026
• quantity: 1
• availability: In Stock
• options: Ship-to-home
• sold: 0

returns ouboaen:

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

general ouboaen:

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

shipping ouboaen:

• service: Standard
• transit: 2-5 Days
• type: Fixed
• cost: $0.00
• class: Standard

payments ouboaen:

• wallet: Apple-pay
• credit card: Visa
• other

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