MERCURY FORCE 99170A2 Tilt Tube Nut 90HP 115HP KF5

( Brand: Mercury Force ), ( Manufacturer Part Number: 99170A2 ), ( Part Type: Tube )

Review MERCURY FORCE Tilt Tube Nut 90hp 115hp Many Kf5 fits 1998

The **Mercury Force 99170A2 Tilt Tube Nut** is a high-performance, precision-engineered component designed specifically for the **Mercury KF5 90 HP and 115 HP outboard motors** from the **1998 model year**, ensuring optimal functionality and reliability for marine applications. This robust tilt tube nut is crafted from durable, corrosion-resistant materials to withstand the harsh conditions of saltwater, frequent exposure to moisture, and the mechanical stresses of frequent tilting and trimming operations. Engineered with a **threaded design** that securely fastens to the tilt tube assembly, it plays a critical role in maintaining the proper alignment and smooth operation of the motor s tilt mechanism, allowing for effortless adjustments between the running and tilting positions. The **99170A2** is compatible with the **KF5 series**, which is renowned for its powerful performance and versatility, making it ideal for everything from fishing boats and personal watercraft to utility vessels and recreational crafts. Whether you're navigating calm lakes or tackling rough seas, this tilt tube nut ensures that your motor operates with precision, reducing wear on the tilt linkage and extending the overall lifespan of your outboard. Its seamless integration into the motor s tilt system enhances maneuverability, making it an indispensable part of maintaining the efficiency and longevity of your Mercury KF5 engine.

**Pros and Cons of buying a Mercury Force 99170A2 Tilt Tube Nut for a 1998 90HP/115HP KF5 Outboard Motor**

### **Pros**

1. **Compatibility** The 99170A2 is specifically designed for the 90HP and 115HP KF5 series outboards from the late 1990s, ensuring a proper fit without modification. This reduces the risk of improper installation or performance issues.

2. **Improved Reliability** If the original tilt tube nut is worn, cracked, or stripped, replacing it with an OEM or high-quality aftermarket part like this one can prevent leaks, misalignment, or failure during operation. A secure tilt tube nut is critical for safe and smooth tilting.

3. **Durability** Mercury Force parts are engineered to meet or exceed factory specifications, often using materials and machining processes that resist corrosion and wear better than generic replacements.

4. **Ease of Installation** Since this is a direct replacement, it should fit without requiring additional tools or adjustments beyond standard outboard maintenance procedures. Many owners report that it installs quickly with basic wrenches.

5. **Cost-Effective Upgrade** Compared to full tilt tube assemblies or engine replacements, this part is relatively inexpensive. Replacing a single worn component is far cheaper than addressing broader mechanical failures caused by a failing tilt mechanism.

6. **Preventative Maintenance** Regularly replacing high-stress components like tilt tube nuts extends the overall lifespan of the outboard. This part is often overlooked until it fails, so proactive replacement can save time and money in the long run.

7. **Warranty Coverage** If purchased from a reputable dealer or brand-authorized seller, the part may come with a warranty, providing peace of mind against defects.

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### **Cons**

1. **Potential Counterfeit Parts** Some aftermarket parts, especially those sold online without verification, may be counterfeit or low-quality replicas. This can lead to premature failure or poor performance. Always buy from trusted sources like Mercury dealers, marine supply stores, or verified online retailers.

2. **Installation Challenges** While designed for easy replacement, rust, corrosion, or improper removal of the old nut could make installation difficult. In some cases, the old nut may need to be drilled out or cut, requiring additional tools.

3. **Limited Availability** As older outboard models become less common, finding this specific part may be harder than for newer engines. Stock may be limited at local dealers, necessitating online orders or longer wait times.

4. **Mismatched Threads or Damage** If the tilt tube or surrounding components are damaged (e.g., stripped threads, bent housing), the new nut may not function correctly. A thorough inspection of the tilt mechanism is recommended before installation.

5. **Skill Dependency** While straightforward, improper installation such as overtightening or misalignment can cause issues. Those unfamiliar with outboard maintenance may benefit from consulting a mechanic or following detailed instructions.

6. **Cost Relative to Full Replacement** If the tilt tube or other related components are also worn, replacing just the nut may not fully resolve the problem. In such cases, a more comprehensive repair might be necessary, increasing overall costs.

7. **Environmental Factors** Exposure to saltwater, freshwater corrosion, or prolonged storage without maintenance can accelerate wear on the new nut. Regular upkeep remains essential for longevity.

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### **Conclusion**

The Mercury Force 99170A2 tilt tube nut is a **practical and cost-effective solution** for maintaining or restoring functionality to a 1998 90HP/115HP KF5 outboard. Its compatibility, durability, and ease of installation make it a sound choice for owners looking to prevent tilt mechanism failures. However, the risk of counterfeit parts, potential installation difficulties, and the need for thorough inspection of surrounding components are factors to consider.

For most DIYers or those with basic mechanical skills, this part is a **recommended upgrade** especially if the original nut is visibly worn or leaking. If in doubt about installation or if other tilt components are compromised, consulting a marine technician ensures a proper and long-lasting fix.

Purchase the part from an authorized Mercury dealer or a trusted marine supply retailer to avoid counterfeit items. Inspect the tilt tube and surrounding hardware before installation, and follow the manufacturer s torque specifications to ensure a secure fit. If the tilt mechanism shows signs of broader wear, consider addressing those issues simultaneously for optimal performance. Overall, this is a **worthwhile investment** for maintaining the reliability and safety of your outboard.

Details:

As pictured freshwater from a 115hp.

part #: 99170a2 prices

• $29.04-$141.40

specifications ouboaen:

• for makes: Mercury
• for years: 1998
• brand: Mercury Force
• mpn: 99170a2
• part type: Tube

payments ouboaen:

• other
• credit card: Visa
• wallet: Google-pay

returns ouboaen:

• policy: No Returns

seller ouboaen:

• rating: 99.7%
• # reviews: 2110
• city: Leavenworth, Kansas

general ouboaen:

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

offer ouboaen:

• quantity: 1
• started: May 4, 2026
• sold: 0
• options: Ship-to-home
• availability: In Stock

shipping ouboaen:

• cost: $0.00
• type: Fixed
• service: Economy
• transit: 3-7 Days
• class: Economy

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