YAMAHA F4T555 Outboard Flywheel Noic 91029A

( Manufacturer Part Number: F4T555 ), ( Model: 91029A ), ( Part Type: Hp Flywheel ), ( Country Of Origin: Japan )

Review YAMAHA Outboard Flywheel Noic Hp Stroke fits 300 350

The **Yamaha F4T555 Outboard Flywheel (NOIC 91029A)** is a precision-engineered component designed exclusively for Yamaha s high-performance 300 to 350 horsepower outboard motors, ensuring optimal power transfer, reliability, and efficiency in demanding marine applications. Crafted from high-grade, heat-treated steel, this flywheel is engineered to withstand the intense rotational forces and thermal stresses encountered during extended operation, making it a critical element in maintaining the longevity and performance of your Yamaha outboard. The flywheel s robust construction features a smooth, balanced design that minimizes vibration, reducing wear on the engine s drivetrain and enhancing overall ride comfort. Its precise machining and tight tolerances ensure seamless integration with the engine s crankshaft, allowing for efficient power delivery while mitigating the risk of premature failure or misalignment. Whether you re navigating rough waters, towing heavy loads, or cruising at high speeds, this flywheel delivers the durability and responsiveness required to keep your Yamaha outboard running at peak performance. Built to Yamaha s stringent quality standards, the F4T555 flywheel is a direct-fit replacement, compatible with select models in the 300 350 hp range, and is backed by Yamaha s reputation for innovation and reliability in marine propulsion. For boaters who demand nothing less than excellence, this component is an essential upgrade or replacement part that ensures your outboard operates with the precision and power it was designed for.

The Yamaha F4T 555 outboard (with the NOIC 9100 series flywheel, specifically the 91029A) is a powerful and popular choice for larger boats, offering high performance and reliability. Below are the key pros and cons of purchasing one in the 300 350 hp range, followed by a conclusion and recommendation.

### **Pros of the Yamaha F4T 555 (300 355 hp) with NOIC 91029A Flywheel**

1. **Reliability and Durability**

Yamaha s F-Series outboards are known for their robust construction and long-term dependability. The F4T 555 is built with a forged crankshaft, high-pressure die-cast aluminum block, and a reinforced lower unit, making it suitable for heavy-duty use. The NOIC 91029A flywheel is a well-regarded part, designed to handle high torque and reduce vibration, which extends engine life.

2. **Power and Performance**

The 300 355 hp range provides strong acceleration and top-end speed, making it ideal for cruising, planing, and towing. The F4T 555 delivers smooth power delivery, with a torquey mid-range that excels in both open-water and rough conditions. The NOIC flywheel helps optimize power transfer, improving efficiency and reducing strain on the engine.

3. **Fuel Efficiency and Low Operating Costs**

Compared to similar outboards in this power class, the F4T 555 offers good fuel economy, especially when cruising. Yamaha s fuel injection system ensures consistent performance and reduces the risk of clogging or misfires. Maintenance costs are relatively moderate, though they depend on usage and upkeep.

4. **Low-Vibration Design**

The NOIC 91029A flywheel is specifically engineered to minimize vibration, which is a common issue in high-horsepower outboards. This reduces fatigue for the operator and passengers, as well as wear on the boat s transom and engine mounts. A smoother ride also enhances comfort during long trips.

5. **Compatibility and Aftermarket Support**

The F4T 555 is widely used, meaning parts, service manuals, and tuning options are readily available. The NOIC flywheel is a popular upgrade, and many marine mechanics are familiar with its installation and benefits. This makes repairs and modifications easier to source.

6. **Resale Value**

Yamaha outboards hold their value well, and the F4T 555 is no exception. A well-maintained unit in this power range retains a significant portion of its original value, making it a sound long-term investment.

7. **Environmental Considerations**

Yamaha has made strides in reducing emissions, and the F4T 555 complies with EPA and CARB standards. It also features a catalytic converter and other emissions-control technologies, which is important for boaters in regulated areas.

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### **Cons of the Yamaha F4T 555 (300 355 hp) with NOIC 91029A Flywheel**

1. **High Initial Cost**

A new or high-quality used F4T 555 in this power range can be expensive, especially when factoring in installation, labor, and potential upgrades like the NOIC flywheel. Even used units may require significant investment to bring them up to optimal condition.

2. **Complex Maintenance Requirements**

High-horsepower outboards demand regular maintenance, including oil changes, fuel system cleaning, and cooling system checks. The NOIC flywheel, while beneficial, adds another layer of complexity if not installed or serviced correctly. Neglecting maintenance can lead to costly repairs.

3. **Weight and Handling**

The F4T 555 is heavy, particularly in the 300 355 hp range, which can make installation and handling difficult. Boats with limited deck space or weak transoms may require reinforcement or professional installation to support the weight safely.

4. **Fuel and Oil Consumption**

While fuel efficiency is decent, higher horsepower engines consume more fuel and oil than smaller outboards. This increases operating costs, especially for frequent or long-duration use. Oil changes must be done more frequently to prevent sludge buildup.

5. **Noise and Exhaust Considerations**

Larger outboards are inherently louder than smaller ones. The F4T 555 produces noticeable noise at high speeds, which may be a concern for boaters who prioritize quiet operation. Exhaust systems must be properly vented to avoid carbon monoxide buildup in enclosed spaces.

6. **Potential for Overpowering the Boat**

If the boat is not properly sized for 300 355 hp, the engine may struggle to plane efficiently or could cause excessive wear on the hull. A boat that is too small for this power range may experience rough handling, excessive fuel consumption, or even structural stress.

7. **Depreciation Over Time**

While Yamaha outboards hold value well, high-horsepower models may depreciate faster than smaller engines due to their specialized components and higher initial cost. Used market prices can fluctuate based on demand and condition.

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### **Conclusion**

The Yamaha F4T 555 with the NOIC 91029A flywheel is an excellent choice for boaters who need a powerful, reliable, and smooth-running outboard in the 300 355 hp range. Its strengths in durability, low vibration, and performance make it ideal for cruising, towing, and high-speed planing. However, the high upfront cost, maintenance demands, and potential handling challenges must be carefully considered.

- Larger boats (e.g., 22 28 feet or more) with adequate displacement and transom strength.

- Boaters who prioritize long-term reliability and are willing to invest in regular maintenance.

- Those who need a balance of power, efficiency, and comfort, especially in rough or mixed conditions.

If budget allows, a new or lightly used F4T 555 with the NOIC flywheel is a strong recommendation for serious anglers, cruisers, or performance-oriented boaters. For those on a tighter budget, a well-maintained used unit with a verified service history could be a cost-effective alternative.

- Your boat is properly sized for 300 355 hp.

- You are prepared for regular maintenance and potential higher operating costs.

- You value smooth operation, reliability, and Yamaha s reputation for quality.

- Your boat is too small or not structurally reinforced for this power range.

- You cannot commit to the maintenance required to keep the engine running efficiently.

- You are looking for a budget-friendly option, as the initial and long-term costs may be prohibitive.

Details:

Please inquire for pricing prior to purchase. UPS Next Day Air may be available for orders over $500 at an extra cost. 1 00% Genuine Us A E L R. Money Back or exchange guaranteed.

part #: f4t555 prices

• $92.04-$225.94

specifications ouboaen:

• for models: 300, 350
• for makes: Yamaha
• mpn: F4t555
• model: 91029a
• part type: Hp Flywheel
• country of origin: Japan

general ouboaen:

• condition: New other see details
• Boat Parts > Outboard Engines Components > Other

seller ouboaen:

• # reviews: 32027
• city: North Salt Lake, Utah
• rating: 99.6%

offer ouboaen:

• availability: In Stock
• options: Ship-to-home
• best offers: True
• started: March 18, 2026
• quantity: 1
• sold: 0

payments ouboaen:

• credit card: Diners-club
• other
• wallet: Google-pay

returns ouboaen:

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

shipping ouboaen:

• carrier: USPS
• type: Fixed
• transit: 3-7 Days
• cost: $0.00
• service: USPS Ground Advantage
• class: Standard

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