Ignition Coil – Fits Mercury 225HP 250HP 275HP 300HP 350HP (Replaces 339-880615T01, 880615T01)

Product Details

This Ignition Coil – Fits Mercury 225HP 250HP 275HP 300HP 350HP is an aftermarket replacement designed for Mercury outboard engines ranging from 225HP to 350HP. Engineered to deliver reliable spark ignition across high-performance applications, this coil ensures consistent engine operation and throttle response.

Direct replacement for Mercury OEM part numbers 339-880615T01 and 880615T01, offering a cost-effective solution without compromising reliability.

• Straightforward bolt-on installation using existing mounting points
• Compatible with gasoline-powered outboard applications
• Designed for marine environments with corrosion-resistant construction

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

Part Type

Ignition Coil

Application

Mercury Outboard Engines

Horsepower Range

225HP – 350HP

Replaces OEM

339-880615T01, 880615T01

What's in the Box

• 1× Ignition Coil

Installation Notes

1. Disconnect the battery negative terminal and allow the engine to cool completely.
2. Locate the faulty ignition coil on your Mercury outboard engine.
3. Disconnect the electrical connector and remove any retaining bolts securing the old coil.
4. Remove the old ignition coil from its mounting position.
5. Position the new ignition coil in the same location and secure with the original hardware.
6. Reconnect the electrical connector, ensuring a firm and complete connection.
7. Reconnect the battery and test engine operation before returning to service.

Troubleshooting & FAQ

How do I know if my ignition coil is failing?

Common symptoms include engine misfires, rough idle, difficulty starting, reduced power, or complete loss of spark on one or more cylinders. Use a multimeter to test resistance or swap coils between cylinders to isolate the fault.

Can I replace just one coil or should I replace all of them?

You can replace a single faulty coil. However, if your engine has high hours or multiple coils are near the same age, replacing all at once can prevent repeat failures and simplify maintenance.

Will this coil work with my specific engine serial number?

This coil fits Mercury outboards rated 225HP to 350HP that originally used part numbers 339-880615T01 or 880615T01. Always verify your engine's OEM part number before ordering.

What is the typical lifespan of an ignition coil?

Lifespan varies with operating conditions, but coils generally last several hundred hours. Saltwater environments, heat, and vibration can accelerate wear. Inspect coils during routine maintenance.

Do I need to gap or adjust anything after installation?

No. This ignition coil is a direct-fit replacement with no adjustment required. Ensure all electrical connections are clean and secure for optimal performance.

What tools are required for installation?

Basic hand tools such as socket wrenches and screwdrivers are typically sufficient. A multimeter is helpful for diagnostic testing before and after replacement.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

• Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.