Alternator – Fits Mercury Outboards V-6 DFI/Optimax (Replaces 8M0064020, 881247A1, 875286A1)

$580.00 $928.00

Shipping calculated at checkout.

Alternator – Fits Mercury Outboards V-6 DFI/Optimax (Replaces 8M0064020, 881247A1, 875286A1) is backordered and will ship as soon as it is back in stock.

Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This high-quality replacement Alternator fits Mercury Outboards with V-6 DFI/Optimax technology. It is specifically designed for use on 200-225 HP 3.0L models, providing reliable charging performance.

This unit serves as a direct interchange for Mercury part numbers 8M0064020, 8M6013461, 881247A1, 875286A1, 828506, and 875286T.

Installs as a direct replacement for the original OEM part.
Features a connection compatible with the factory OEM wiring harness.
Covered by a 1-year warranty when purchased new.

Part Number Matrix

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

Brand	Part Number	Superseded By
Mercury	8M0064020	8M6013461
Mercury	881247A1
Mercury	875286A1
Mercury	828506
Mercury	875286T

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury engines, please ensure your model is a V-6 3.0L with DFI/Optimax technology.

Brand	Model	Rated HP	Stroke	OEM Part No.	Notes
Mercury	Optimax/DFI V-6 3.0L	200-225	2-Stroke	8M0064020	Superseded by 8M6013461

Technical Specs

Product Type: Alternator
Installation: Direct Replacement OEM
Connection: OEM Wiring Harness Compatible
Housing Color: Black
Product Dimensions (L x W x H): 19.0 x 19.0 x 20.5 cm
Warranty: 1 Year (when purchased new)
Other Technical Attributes: 12V System, Delco/Remy Design

What’s in the Box

1 x Alternator (8M0064020/8M6013461)

Installation Notes

Disconnect the negative terminal from your boat's battery to prevent electrical shorts.
Loosen the belt tensioner and carefully remove the serpentine belt from the alternator pulley.
Unplug the main wiring harness and disconnect the battery cable from the back of the old alternator.
Remove the mounting bolts securing the alternator to the engine block.
Carefully lift the old alternator out of the engine bay.
Position the new alternator and loosely tighten the mounting bolts.
Reconnect the electrical connectors and battery cable.
Reinstall the serpentine belt and apply the correct tension using the tensioner.
Tighten all mounting bolts to the manufacturer's specified torque.
Reconnect the battery terminal, start the engine, and verify the charging system is operating correctly.

Troubleshooting & FAQ

How do I know if my alternator is failing?

Common signs of a faulty alternator include dimming or flickering lights, a battery warning light on your dashboard, a weak or dead battery, frequent battery jumps, or a whining/grinding noise coming from the engine area.

Will this alternator fit my Optimax engine?

This unit is specifically designed as a replacement for alternators on Mercury V-6 DFI/Optimax 3.0L (200-225 HP) engines. To guarantee fitment, always compare your original part number to the references listed in our Part Number Matrix.

Do I need to modify my boat's wiring?

No. This alternator is engineered to be compatible with the factory OEM wiring harness, allowing for a direct, plug-and-play installation without any modifications.

What is the output amperage of this alternator?

While a specific amperage rating is not provided, this alternator is manufactured to meet or exceed the electrical demands and specifications of the original factory part for all listed compatible models.

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 vs 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.

Payment & Security

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