MERCURY 855685T Outboard Ignition Coil 9-15 4-STROKE

( Manufacturer Part Number: 855685T ), ( Part Type: Ignition Hp Coil )

Review MERCURY 9-15 Hp 4-stroke Outboard Ignition Coil Oem Used

The **Mercury 4-stroke Outboard Ignition Coil (Part #855685T, 9-15 HP)** is a precision-engineered component designed to deliver reliable and high-performance spark generation for Mercury s compact yet powerful 4-stroke outboard motors in the 9 to 15 horsepower range. This coil is a critical part of the engine s ignition system, responsible for producing the high-voltage electrical discharge necessary to ignite the air-fuel mixture in the combustion chamber with precision and efficiency. Built to Mercury s exacting standards, this coil features a robust, corrosion-resistant construction that ensures durability in marine environments where exposure to saltwater, humidity, and constant vibration can compromise lesser-quality components. Its advanced winding technology and high-quality core materials optimize spark consistency, reducing misfires and enhancing overall engine performance, which translates to smoother operation, better fuel efficiency, and extended engine life. The coil s compact yet sturdy design integrates seamlessly with the motor s ignition system, providing a secure and reliable connection that minimizes electrical interference and maximizes power output. Whether used in recreational boats, fishing vessels, or utility applications, this ignition coil is engineered to withstand the demands of daily use while maintaining the integrity of the engine s ignition process. Replacing an aging or faulty coil with this genuine Mercury part ensures that your outboard operates at peak efficiency, reducing the risk of unexpected breakdowns and maintaining the motor s warranty coverage. Ideal for both new installations and replacements, the **Mercury 855685T** is a testament to the brand s commitment to quality and performance, offering boat owners a dependable solution for keeping their 4-stroke outboards running strong.

**Pros and Cons of buying a Mercury 855685T 9-15 HP 4-Stroke Outboard Ignition Coil**

The Mercury 855685T is a replacement ignition coil designed for 9-15 HP 4-stroke outboard motors, including models from Mercury s Verado, FourStroke, and other compatible engines. Below is a detailed breakdown of its advantages and drawbacks, followed by a conclusion and recommendation.

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### **Pros**

1. **OEM Quality and Compatibility**

The coil is manufactured by Mercury Marine, a well-known brand in the marine industry, ensuring high-quality materials and engineering. It is designed specifically for Mercury s 9-15 HP 4-stroke outboards, reducing the risk of fitment issues or performance problems. This makes it a reliable choice for owners who want genuine parts that match their engine s specifications.

2. **Reliability and Durability**

Mercury s components are built to withstand the harsh conditions of marine environments, including exposure to saltwater, vibration, and temperature fluctuations. A high-quality ignition coil like this one is less likely to fail prematurely, reducing the need for frequent replacements. This can save time and money in the long run, especially for boats used regularly.

3. **Performance Consistency**

The coil is engineered to work seamlessly with the engine s ignition system, ensuring consistent spark generation. This contributes to smoother starts, better fuel efficiency, and optimal power delivery. For small outboards, reliable ignition is critical, as issues here can lead to stalling or poor acceleration.

4. **Ease of Installation**

As an OEM part, the coil is designed to fit directly into the engine s ignition system without requiring extensive modifications. Installation typically involves removing the old coil, connecting the new one to the wiring harness, and securing it in place. This simplicity makes it accessible for DIYers or even less experienced boat owners.

5. **Warranty Coverage**

Mercury Marine often provides warranties on OEM parts, offering some level of protection against defects. This can provide peace of mind, especially if the coil fails shortly after purchase. Warranty terms vary, so it s important to check the specific coverage when buying.

6. **Aftermarket Support**

Since Mercury is a major brand, finding replacement parts, diagnostic tools, or technical support is straightforward. Dealers and online resources are readily available to assist with installation, troubleshooting, or further upgrades.

7. **Preventative Maintenance**

Replacing an old or failing ignition coil with a new OEM part can be a proactive maintenance step. Ignoring ignition issues can lead to more severe problems, such as engine damage or failure. Addressing the coil early can extend the life of the entire outboard motor.

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### **Cons**

1. **Cost**

OEM parts from Mercury are generally more expensive than aftermarket alternatives. The price of the 855685T coil may be higher than comparable third-party coils, which could be a deterrent for budget-conscious buyers. However, the cost is often justified by the reliability and longevity of the part.

2. **Limited Availability**

While Mercury parts are widely available through dealers and online retailers, some specialized or older models might have limited stock. This could require ordering in advance or waiting for delivery, which may not be ideal for urgent repairs.

3. **Potential Overkill for Some Uses**

If the outboard motor is used infrequently (e.g., seasonal recreational use), the high-quality coil may outlast its necessity. In such cases, a slightly less expensive aftermarket coil might suffice without compromising performance.

4. **Installation Complexity for Non-Mechanics**

While the installation is generally straightforward, those unfamiliar with marine engines might find it challenging. Mistakes during installation, such as incorrect wiring or improper torque, could lead to further issues. In such cases, hiring a professional may add to the overall cost.

5. **Environmental Factors**

Even high-quality coils can degrade over time due to prolonged exposure to saltwater, corrosion, or physical stress. Regular maintenance, such as cleaning the coil and checking connections, is necessary to ensure longevity. Neglecting these steps can reduce the coil s lifespan regardless of its quality.

6. **Compatibility Confusion**

While the coil is designed for a specific range of engines, there may be confusion about exact model compatibility. For example, some older or modified outboards might not fit perfectly, requiring additional adapters or modifications. Always verify compatibility with the engine s manual or a dealer before purchasing.

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### **Conclusion**

The Mercury 855685T ignition coil is a high-quality, reliable replacement part for 9-15 HP 4-stroke outboard motors. Its OEM status ensures compatibility, durability, and performance consistency, making it an excellent choice for owners who prioritize quality and longevity. The coil s ease of installation and support from Mercury s extensive network further add to its appeal.

However, the higher cost compared to aftermarket options and the need for careful installation or maintenance are potential drawbacks. For most boat owners, especially those who use their outboards regularly or rely on them for critical functions, the benefits of the Mercury coil outweigh the drawbacks. It is a sound investment for maintaining or restoring the performance of a Mercury 4-stroke outboard.

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### **Recommendation**

If you are replacing an ignition coil in a Mercury 9-15 HP 4-stroke outboard and prioritize reliability, performance, and peace of mind, the **Mercury 855685T ignition coil is highly recommended**. It is the best choice for ensuring seamless operation and longevity of your engine.

For budget-conscious buyers or those with less frequent use, consider comparing the price of the OEM coil with high-quality aftermarket alternatives (e.g., from brands like Seafoam, Mercruiser, or other reputable marine part manufacturers). However, be cautious of very low-cost coils, as they may lack the durability or compatibility needed for reliable performance.

Before purchasing, verify the exact model and year of your outboard to confirm compatibility. If in doubt, consult a marine mechanic or Mercury dealer for guidance. Regular maintenance, including cleaning the coil and checking electrical connections, will further extend its lifespan and ensure optimal engine performance.

Details:

This is a good used OEM Mercury four stroke ignition coil. Came off of a 2008 15hp.

part #: 855685t prices

• $26.00-$130.57

specifications ouboaen:

• for makes: Mercury
• mpn: 855685t
• part type: Ignition Hp Coil

general ouboaen:

• Boat Parts > Outboard Engines Components > Ignition Starting Systems
• condition: Used

offer ouboaen:

• options: Ship-to-home
• quantity: 1
• started: February 17, 2026
• availability: In Stock
• sold: 0

returns ouboaen:

• policy: No Returns

shipping ouboaen:

• service: USPS Ground Advantage
• cost: $10.50
• type: Calculated
• carrier: USPS
• transit: 4-10 Days
• class: Standard

seller ouboaen:

• # reviews: 1375
• rating: 99.5%
• city: Lenoir City, Tennessee

payments ouboaen:

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

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