21-64871

The Quicksilver 21-64871 Check Valve is an essential component for Mercury outboard sterndrive systems manufactured between 1970 and 2010. This valve is designed to prevent the flow of water from moving backward through the cooling system, ensuring efficient engine performance and reliable operation.

The Quicksilver check valve is meticulously constructed using high-quality materials. Its body is crafted from durable brass, providing excellent resistance to corrosion and ensuring a long service life. The valve's internal components, including the seats and springs, are made of stainless steel, further enhancing its durability and resistance to wear and tear.

The Quicksilver check valve features a compact, yet robust design. It is a single-disc, diaphragm-type check valve, which allows for smooth and efficient water flow in the forward direction. When water pressure decreases in the engine, the valve's diaphragm collapses, sealing off the inlet and preventing water from flowing backward.

Installation of the Quicksilver check valve is straightforward. It is designed to fit directly into the Mercury outboard sterndrive cooling system, making it a straightforward replacement for worn-out or failing check valves. The valve comes with all necessary mounting hardware, ensuring a hassle-free installation process.

In summary, the Quicksilver 21-64871 Check Valve is a high-quality, reliable, and durable replacement component for Mercury outboard sterndrive systems manufactured between 1970 and 2010. Its brass body and stainless steel internal components ensure excellent resistance to corrosion and wear, while its compact design and easy installation make it an excellent choice for boat owners seeking to maintain their engines' optimal performance.

Quicksilver 21-64871 1970-2010 Mercury Check Valve Outboard Sterndrive: A Comprehensive Analysis

The Quicksilver 21-64871 check valve is a crucial component in the cooling system of Mercury outboard sterndrives manufactured between 1970 and 2010. This analysis aims to provide you with an unbiased assessment of the product's pros and cons to help you make an informed decision about purchasing it.

1. Durability: Quicksilver check valves are known for their robustness and long-lasting performance. They are designed to withstand the rigors of continuous marine use.

2. Functionality: The valve's primary function is to prevent the backflow of water from the outdrive when the engine is not running. It ensures that the cooling system remains filled with water, thus preventing overheating.

3. Availability: These check valves are widely available in the market, making it easier for boat owners to replace them when needed.

4. Easy installation: The installation process for these check valves is generally straightforward and can be accomplished by most DIY boat owners.

1. Age: Given that this check valve is designed for outboard sterndrives manufactured between 1970 and 2010, it may not meet the latest performance standards.

2. Potential for leakage: Over time, the seals on the check valve may deteriorate, leading to leakage. This could result in a decrease in cooling system efficiency or even engine damage.

3. Limited compatibility: This specific Quicksilver check valve is only compatible with Mercury outboard sterndrives from the specified period. It may not fit other makes or models.

In conclusion, the Quicksilver 21-64871 check valve is a reliable and durable solution for cooling system issues in Mercury outboard sterndrives manufactured between 1970 and 2010. However, it's essential to consider its age and potential for leakage. Regular maintenance and timely replacement can help mitigate these concerns. If you own a Mercury outboard sterndrive from the specified period and are experiencing cooling system issues, this check valve could be a worthwhile investment.

If you are in the market for a new check valve for your Mercury outboard sterndrive, the Quicksilver 21-64871 is a solid choice. However, it's always a good idea to consult your engine manual or a trusted marine mechanic to ensure that this is the correct valve for your specific application. Additionally, consider having the valve installed by a professional to guarantee proper installation and function.

Details:

Spotlight: a day inside . A new factory part, it provides critical one-way flow control for various outboard and sterndrive applications. The image to watch on YouTube. Fits: fits a wide range of Mercury/mariner outboards and Mercuries sterndrive from 1970s to 2010.

This is a genuine Mercury Quicksilver oem check valve, part number 21-64871, ensuring reliable performance in fuel, oil, or cooling systems.

specifications inboardfuel:

• for makes: Mercury
• for years: 1970–2010
• brand: Quicksilver
• mpn: 21-64871
• part type: Valve Check Sterndrive
• country of origin: United States
• manufacturer warranty: Unspecified Length
• storage location: I2 Zsc-n Buk 28 Bin 4

general inboardfuel:

• category: Boat Parts > Inboard Engines Components > Intake Fuel Systems

payments inboardfuel:

• other
• wallet: apple-pay
• credit card: mastercard

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• time: 30 days
• policy: returns accepted
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• city: odessa, florida
• rating: 99.2%
• # reviews: 2001 54

offer inboardfuel:

• best offers: true
• options: ship-to-home
• started: december 11, 2025
• in stock #: 5
• prices: $4.99–$70.00
• item condition:
  • New other (see details)
  • New
• sold #: 12
• availability: in stock

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• type: fixed

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