fits year: 1969–1983.

( Brand: Mercruiser ), ( Manufacturer Part Number: 1623-5412-S2 ), ( Part Type: Unit ), ( Country Of Manufacture: United States ), ( Surface Finish: Painted Black ), ( Warranty: 30 Days ), ( Color: Black )
The 1623-5412-S2 Mercruiser unit is a vintage yet powerful outboard engine, specifically the 165hp Alpha PreAlpha Lower model, manufactured between 1969 and 1983. This unit is a testament to Mercruiser's engineering prowess during its formative years.
The 1623-5412-S2 is a two-stroke, direct-injection, outboard engine that delivers an impressive 165 horsepower. It's equipped with a pre-alpha lower unit, which is known for its exceptional performance and reliability. The engine features a unique dual-carburetor setup, ensuring optimal fuel-air mixture for efficient combustion and maximum power output.
The engine block is made of high-strength aluminum alloy, providing excellent resistance to corrosion and ensuring longevity. The engine's crankshaft is robust and has been designed to handle the high power output, ensuring smooth and reliable operation. The 1623-5412-S2 also features a high-compression piston design, which helps improve the engine's power-to-weight ratio and overall performance.
The unit's lower unit is a pre-alpha design, which is known for its superior performance and durability. It features a heavy-duty gear case and a high-strength prop shaft, ensuring smooth and efficient power transmission to the propeller. The lower unit is also equipped with a manual oil pump, ensuring that the lower unit is always properly lubricated for optimal performance.
The 1623-5412-S2 Mercruiser unit is a true classic and a valuable addition to any vintage boat enthusiast's collection. Its unique design, powerful performance, and reliable operation make it a sought-after item in the world of vintage marine engines. Whether you're a collector, a restorer, or a vintage boat enthusiast, this Mercruiser unit is a must-have in your arsenal.
Pros of buying a 1623-5412-S2 1969-1983 Mercruiser Alpha PreAlpha Lower Unit 165 HP:1. Powerful and Reliable: With a 165 HP, this unit is capable of providing strong power and speed for your boat.
2. Widely Available: Being a popular and classic model, parts and service for this unit are readily available, making maintenance and repairs easier.
3. Affordable: Compared to newer models, the price for this unit can be more budget-friendly.
Cons of buying a 1623-5412-S2 1969-1983 Mercruiser Alpha PreAlpha Lower Unit 165 HP:1. Outdated Technology: The unit may not have the latest technology and features available in newer models.
2. Potential for Wear and Tear: Being an older model, the unit may have some wear and tear or potential issues due to age.
3. Limited Compatibility: The unit may not be compatible with newer boats or have the necessary connections for modern electronics.
Conclusion:While the 1623-5412-S2 1969-1983 Mercruiser Alpha PreAlpha Lower Unit 165 HP offers a reliable and powerful engine, it is important to consider the potential drawbacks, such as outdated technology and potential issues due to age. Before making a decision, it's recommended to research the unit's history and have it inspected by a professional to ensure its condition is acceptable. Additionally, consider how well it fits with your boat's needs and compatibility with modern electronics.
Recommendation:If you are looking for a budget-friendly and reliable engine, the 1623-5412-S2 1969-1983 Mercruiser Alpha PreAlpha Lower Unit 165 HP may be a good option. However, it's important to thoroughly research the unit and have it inspected to ensure it is in good working condition and meets your specific needs. If you prioritize newer technology and modern features, it may be worth considering a newer model instead.
The driveshaft measures with a spline count of 13. The prop shaft spline count is 15. Boat had much of the inner fiberglass cut out and a poorly installed custom interior, hull was too far gone to rebuild so became parts.
All of the gears are in flawless condition and work great. Was removed from a good running boat that fresh water only. This unit is shifting in and out of gear smoothly. The paint is in decent condition, not a show piece but looks good, and housing has been opened inspected.
Fits: pre alpha r and Mr 165 engines. For the age of this unit it is in very good condition.