WEBER NA9661S Barrel Carburetor Electric Choke 5.7L

( Brand: Weber ), ( Manufacturer Part Number: NA9661S ), ( Model: NA9661S 2052 ), ( Color: Black ), ( Engine Hp : 5.7 Liter Mercuiser Engine ), ( Material: Metal ), ( Item Length: 10 ), ( Type: Carburetor ), ( Country Of Origin: United States )

Review WEBER Barrel Carburetor 5.7l Electric Choke fits MERCRUISER MARINE 350

The **Weber NA9661S Mercruiser Marine Barrel Carburetor** is a high-performance, precision-engineered fuel delivery system designed exclusively for marine applications, specifically tailored to power the iconic 350 cubic-inch (5.7-liter) Mercruiser inline-six engines. This robust carburetor features a **barrel-style design**, renowned for its reliability, durability, and ability to deliver consistent throttle response even under the demanding conditions of saltwater environments. Built with marine-grade materials, including corrosion-resistant metals and seals, the NA9661S ensures long-lasting performance while withstanding the harsh effects of humidity, salt spray, and constant exposure to water. The **electric choke mechanism** provides smooth, controlled engine starts in cold or wet conditions, eliminating the need for manual adjustments and reducing wear on the carburetor s internal components. This feature is particularly advantageous for boaters who operate in variable climates or frequently launch their vessels in cold water, as it ensures reliable ignition every time without the risk of choke-related malfunctions.

At the heart of the NA9661S is a **high-flow passage system**, meticulously calibrated to optimize fuel-air mixture for maximum power, efficiency, and throttle response. The barrel design enhances airflow dynamics, reducing turbulence and improving combustion efficiency, which translates to smoother acceleration, better fuel economy, and reduced carbon buildup over time. The carburetor s **adjustable throttle linkage** allows for precise tuning, enabling boat owners to fine-tune performance to match their specific driving style or payload requirements. Whether cruising at low speeds or pushing through high RPMs during high-speed runs, the NA9661S delivers a balanced blend of power and control, making it an ideal choice for both performance enthusiasts and those seeking reliable, long-term marine propulsion.

For added convenience and ease of maintenance, the Weber NA9661S is equipped with **quick-disconnect fuel lines**, simplifying installation, removal, and servicing. The carburetor s modular design allows for easy access to critical components such as the jets, float bowl, and throttle body, ensuring that routine cleaning, adjustment, or replacement can be performed with minimal downtime. Additionally, the **marine-specific gaskets and seals** prevent leaks and contamination, safeguarding the engine from fuel dilution or water ingress that could otherwise lead to costly repairs. Whether used in a classic Mercruiser-powered yacht, a high-performance speedboat, or a versatile fishing vessel, this carburetor stands as a testament to Weber s legacy of craftsmanship and engineering excellence, offering a perfect marriage of performance, durability, and adaptability for the marine environment.

### Pros and Cons of Buying a Weber NA9661S Mercruiser Marine Barrel Carburetor (350/5.7L, Electric Choke)

1. **Performance and Power** Weber carburetors are known for delivering strong throttle response and improved power output, especially in marine applications where airflow and fuel mixture are critical. The NA9661S is designed to optimize performance for larger engines like the 350/5.7L Mercruiser, making it ideal for high-performance or modified boats.

2. **Electric Choke System** The inclusion of an electric choke eliminates the need for manual choke adjustments, providing smoother cold starts and reducing wear on the carburetor. This feature is particularly useful in marine environments where frequent starts and stops occur.

3. **Durability and Marine-Grade Construction** Weber carburetors are built to withstand harsh conditions, including saltwater exposure, vibration, and temperature fluctuations. The NA9661S is designed specifically for marine use, which means it is more resistant to corrosion and mechanical stress compared to standard automotive carburetors.

4. **Compatibility with High-Performance Modifications** If you are running a modified engine (e.g., with a supercharger, turbo, or high-lift cam), the Weber NA9661S can handle the increased airflow demands better than stock carburetors. This makes it a popular choice for tuners and racers.

5. **Adjustability** Weber carburetors offer fine-tuning capabilities through jet adjustments, allowing you to optimize fuel mixture for different conditions (e.g., high altitude, different fuel types, or load variations). This flexibility can improve efficiency and performance.

6. **Reputation for Reliability** Weber is a well-established brand in high-performance carburetion, and their marine-specific models are trusted by boat owners, racers, and tuners. The NA9661S has a proven track record in similar applications.

7. **Easier Maintenance Than Fuel Injection** While carburetors require more frequent cleaning and adjustment than fuel injection systems, they are generally simpler to repair and maintain. This can be an advantage for DIYers who prefer mechanical tuning over electronic systems.

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1. **Higher Initial Cost** Weber carburetors are significantly more expensive than stock or aftermarket carburetors designed for stock engines. The NA9661S is a premium product, and the price reflects its performance-oriented design and marine-grade materials.

2. **Maintenance Requirements** Carburetors are prone to clogging from dirt, marine growth (e.g., barnacles, algae), and fuel impurities. Unlike fuel-injected engines, they require regular cleaning, jet adjustments, and inspection of seals and gaskets. Saltwater exposure accelerates wear, so maintenance must be thorough and frequent.

3. **Fuel Efficiency Concerns** Carburetors can be less fuel-efficient than modern fuel-injected engines, especially if not properly tuned. The NA9661S, while powerful, may consume more fuel than a stock or electronically managed system, particularly under heavy load.

4. **Potential for Tuning Challenges** While adjustable, improper tuning can lead to rough idling, stalling, or poor performance. Unlike fuel injection, which often self-adjusts, carburetors require manual intervention to maintain optimal settings, which can be time-consuming.

5. **Vibration Sensitivity** Marine engines are subject to constant vibration, which can loosen gaskets, seals, and internal components over time. The NA9661S is built to handle this, but it may still require more frequent checks for leaks or wear compared to a sealed fuel-injection system.

6. **Limited Availability of Parts** While Weber is a reputable brand, finding replacement parts (e.g., jets, gaskets, or seals) can be more difficult than for mass-produced carburetors or fuel injection components. This may lead to longer wait times for repairs.

7. **Environmental and Emissions Considerations** Older carburetors, including the NA9661S, may not meet modern emissions standards if used in heavily regulated areas. While this is less of an issue for recreational boats, it could be a concern for commercial or heavily inspected vessels.

8. **Learning Curve for Installation** Installing a Weber carburetor, especially on a marine engine, requires mechanical skill and familiarity with carburetion systems. Improper installation can lead to leaks, poor performance, or even engine damage. Professional installation is often recommended.

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### **Conclusion and Recommendation**

The **Weber NA9661S Mercruiser Marine Barrel Carburetor (350/5.7L, Electric Choke)** is an excellent choice for boat owners who prioritize **performance, adjustability, and marine durability** over fuel efficiency or low maintenance. It is particularly well-suited for:

- **High-performance or modified Mercruiser 350/5.7L engines** (e.g., those with forced induction or aggressive camshafts).

- **Boats used in racing, towing, or heavy-duty applications** where raw power and throttle response are critical.

- **Enthusiasts who enjoy tuning and maintaining their engines** and are willing to invest time in carburetor care.

- **Owners who prefer mechanical carburetion over fuel injection**, either for nostalgia, simplicity, or specific performance benefits.

- **Boat owners seeking maximum fuel efficiency** or those who prioritize low maintenance.

- **Those unfamiliar with carburetor tuning**, as improper adjustments can lead to poor performance or engine issues.

- **Commercial or heavily regulated vessels** where emissions compliance may be a concern.

- **Budget-conscious buyers**, as the upfront cost and maintenance expenses are higher than stock or basic aftermarket options.

If you are running a **stock or lightly modified Mercruiser 350/5.7L engine** and are satisfied with its performance, upgrading to a Weber NA9661S may not be necessary unless you specifically need the extra power and adjustability. However, if you are **modifying your engine (e.g., adding a supercharger, turbo, or high-lift cam)** or seeking **superior throttle response and marine reliability**, the NA9661S is a **strong, high-performance choice** provided you are prepared for the **higher cost and maintenance demands**.

For **stock or near-stock engines**, consider evaluating whether the performance gains justify the investment. If you decide to proceed, **professional installation and regular maintenance** are strongly recommended to ensure longevity and optimal performance. Additionally, **explore Weber s support resources** (e.g., tuning guides, local carburetor specialists) to help with setup and adjustments.

Details:

The Mercruiser Marine Weber 4 Barrel Carburetor is a high-quality replacement part designed for 5.7L Mercuiser engines.

part #: na9661s prices

• $299.99-$550.00

specifications completegengin:

• for models: Marine, 350, Mercruiser
• brand: Weber
• mpn: Na9661s
• model: Na9661s 2052
• color: Black
• engine hp : 5.7 Liter Mercuiser Engine
• material: Metal
• item length: 10
• type: Carburetor
• country of origin: United States

seller completegengin:

• rating: 100.0%
• # reviews: 19
• city: Bellingham, Washington

payments completegengin:

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

general completegengin:

• Boat Parts > Inboard Engines Components > Complete Gas Engines
• condition: Used

shipping completegengin:

• transit: 7-11 Days
• service: USPS Ground Advantage
• cost: $14.45
• class: Standard
• carrier: USPS
• type: Calculated

offer completegengin:

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

returns completegengin:

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

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