MERCURY 10-20367 Outboard Screw 50HP 3-CYL 2-STR 7/16 T159

( Manufacturer Part Number: 10-20367 ), ( Part Type: Screw ), ( Country Of Origin: United States )

Review MERCURY 50hp 3-cyl Outboard Screw 7/16 fits 1989

The **Mercury 10-20367 1989 50HP 3-Cylinder Two-Stroke Outboard Motor** is a robust and reliable marine propulsion system designed for mid-sized boats, offering a perfect balance of power, efficiency, and performance for recreational and light fishing applications. Built with Mercury s signature engineering precision, this **7/16-inch T159 propeller** outboard features a **3-cylinder, two-stroke combustion engine** that delivers a smooth, responsive throttle response and a consistent **50 horsepower** output, making it ideal for vessels ranging from 16 to 20 feet in length. The **1989 model year** reflects a classic yet dependable design, characterized by its durable aluminum housing, which is both lightweight and resistant to corrosion, ensuring longevity even in saltwater environments. This outboard operates on a **two-stroke fuel system**, requiring a precise 50:1 oil-to-gasoline mix for optimal performance and engine protection, a hallmark of Mercury s commitment to simplicity and efficiency in marine propulsion.

The **T159 propeller** is a key component, engineered for maximum thrust and fuel economy while maintaining a manageable noise level, allowing for a quieter boating experience. The **3-cylinder configuration** provides a balanced power delivery, reducing vibration and enhancing ride comfort, which is particularly advantageous for extended hours on the water. Mercury s **direct-drive transmission** ensures seamless power transfer from the engine to the propeller, while the **manual shift lever** allows for easy forward and reverse operation, making it user-friendly for both novice and experienced boaters. This outboard is equipped with a **single-lever throttle control**, simplifying operation and reducing the risk of accidental throttle engagement, a safety feature that has been a staple in Mercury s design philosophy for decades.

Built to withstand the demands of recreational boating, the **1989 50HP Mercury** includes a **cast aluminum lower unit** that houses the propeller shaft and bearings, providing durability and resistance to wear. The **oil-cooled cylinder heads** help maintain optimal operating temperatures, preventing overheating and extending the engine s lifespan. While this model predates modern emissions regulations, it remains a sought-after choice for collectors, restorers, and enthusiasts who appreciate its straightforward mechanics and timeless performance. Whether used for leisurely cruising, light fishing, or small watercraft towing, this outboard delivers a reliable and enjoyable boating experience, embodying Mercury s legacy of innovation and craftsmanship in marine engines.

### **Pros and Cons of buying a Mercury 10 HP 1989 3-Cylinder 2-Stroke Outboard (Part #10-20367, 7/16" x 15/9 T159 Prop)**

1. **Affordability** Older Mercury outboards, especially from the late 1980s, are often significantly cheaper than modern engines, making them a budget-friendly option for small boats.

2. **Lightweight and Compact** The 10 HP 3-cylinder design is ideal for small boats, dinghies, or trolling applications where weight and space are concerns.

3. **Simple Mechanics** Two-stroke engines like this one are straightforward in design, which can make repairs and maintenance easier for those with basic mechanical knowledge.

4. **Good for Trolling or Small Boats** The low horsepower is well-suited for leisurely fishing, kayaks, or small powerboats where high speed isn t necessary.

5. **Parts Availability** Mercury outboards from this era still have some aftermarket support, though availability may be limited compared to newer models.

6. **Classic Reliability** Many older Mercury engines were built to last, and with proper maintenance, this one could provide years of service.

1. **Environmental Concerns** Two-stroke engines like this one do not have a crankcase (they rely on oil mixed with fuel), which can lead to oil burning and pollution. Many areas now restrict or ban two-strokes due to environmental regulations.

2. **Fuel Inefficiency** Two-strokes consume fuel at a higher rate than modern four-stroke engines, making them more expensive to operate over time.

3. **Lack of Modern Technology** This engine lacks features like electronic ignition, fuel injection, or modern emissions controls, which can lead to poor performance and reliability compared to newer models.

4. **Limited Power Output** At just 50 HP, this engine is underpowered for most serious boating needs, such as towing, high-speed cruising, or larger boats.

5. **Maintenance Challenges** Two-strokes require frequent oil changes (often every 5-10 hours of use) and are prone to wear if not properly maintained. Over time, internal components like pistons and bearings may degrade.

6. **Regulatory Restrictions** Many marinas, lakes, and states have banned or restricted two-stroke engines due to pollution concerns, making it difficult to use in certain areas.

7. **Difficulty Finding Parts** While some parts may still be available, finding original or compatible replacements for older Mercury engines can be challenging compared to newer models.

8. **Noise and Vibration** Older two-stroke engines tend to be louder and vibrate more than modern four-strokes, which can be uncomfortable for the operator and passengers.

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The Mercury 10 HP 1989 3-cylinder two-stroke outboard is a viable option for very specific applications, such as small trolling boats, kayaks, or as a backup engine where cost is a primary concern. However, its environmental drawbacks, inefficiency, and lack of modern reliability features make it a poor choice for most serious boaters. If you need an engine for occasional use in a restricted area or as a low-cost solution, it may work but for anything else, a modern four-stroke outboard would be a far better investment in terms of performance, efficiency, and compliance with regulations.

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- **Buy if:** You have a very small boat (e.g., a kayak or dinghy), need a backup engine for minimal use, and are willing to deal with the environmental and maintenance limitations.

- **Do not buy if:** You plan to use the engine for regular boating, need reliability, or want to comply with modern environmental standards. Instead, consider a modern four-stroke outboard (e.g., Mercury 5-10 HP four-stroke) for better performance, efficiency, and legal compliance.

If you decide to proceed, ensure you have a reliable mechanic familiar with two-stroke engines to maintain it properly. Otherwise, upgrading to a newer, cleaner, and more efficient engine would be the smarter long-term choice.

Details:

Parts off of a 1989 Mercury 50hp 3-cylinder, 2-Stroke freshwater outboard motor, model 10604129D, serial 0C213633, long shaft for 20 transoms, tiller steer, electric start, power head had poor compression. We operate in Central Standard Time. Recombine shipping on multiple items. Keeping mind that if the listing is for a used part, it used part, so there may be some minor cosmetic damage scratches/scuffs.

They will however be in functioning and usable condition. Just because the part looks right does not mean that Otis. Pleasured entire listing before buying or purchasing item.

part #: 1020367 prices

• $10.99-$14.99

specifications ouboaen:

• for makes: Mercury
• for years: 1989
• mpn: 10-20367
• part type: Screw
• country of origin: United States

shipping ouboaen:

• transit: 2-6 Days
• class: Standard
• type: Fixed
• service: Standard
• cost: $0.00

seller ouboaen:

• city: Melrose, Minnesota
• rating: 99.9%
• # reviews: 5487

returns ouboaen:

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

general ouboaen:

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

payments ouboaen:

• wallet: Paypal
• credit card: Diners-club
• other

offer ouboaen:

• started: April 14, 2026
• availability: In Stock
• quantity: 1
• options: Ship-to-home
• sold: 0

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