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300 Hour Maintenance Kit – Fits Mercury 15-20 HP EFI 4-Stroke Outboards (Replaces 8M0151470)

Sale price $260.25 Regular price $416.00
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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 300 Hour Maintenance Kit – Fits Mercury 15-20 HP EFI 4-Stroke Outboards (Replaces 8M0151470) provides all the essential components for a comprehensive 300-hour service. It is designed specifically for Mercury 15-20 HP EFI 4-Stroke outboard engines with serial number 0R833820 and above, covering models from 2018 to the present.

This kit serves as a direct aftermarket replacement for Mercury OEM part number 8M0151470.

  • Includes all required filters, spark plugs, anodes, and water pump components for a complete 300-hour service.
  • Engineered with OEM-equivalent parts for reliable installation and performance.
  • Consolidates necessary maintenance items into one convenient package.

Part Number Matrix

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

Brand Part Number
Mercury 8M0151470

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Mercury 15 HP EFI 15 4-Stroke 2018–present 8M0151470 Serial number 0R833820 and above
Mercury 20 HP EFI 20 4-Stroke 2018–present 8M0151470 Serial number 0R833820 and above

Technical Specs

Product Type
Maintenance Service Kit
Installation
OEM Factory Maintenance Parts
Fuel Type
Gasoline (EFI)
Housing Material
Various (multiple components)
Housing Color
Various (Mercury OEM)
Dimensions
14.5" L x 18.4" W x 15.9" H
Other Technical Attributes
300-hour service interval maintenance components

What’s in the Box

  • 1 x Oil Filter
  • 1 x High Pressure Fuel Filter
  • 1 x Low Pressure Fuel Filter
  • 1 x Oil Drain Plug Seal
  • 1 x Gearcase Drain Plug Set
  • 2 x NGK DCPR6E Spark Plugs
  • 1 x Lower Unit Anode
  • 1 x Power Tilt Anode
  • 1 x Water Pump Impeller Kit (includes impeller and housing)

Installation Notes

  1. Disconnect the battery and ensure the engine is cool before beginning work.
  2. Drain the engine oil and gearcase lube into appropriate containers.
  3. Replace the old oil filter, fuel filters, spark plugs, and anodes with the new components from the kit.
  4. Service the water pump by replacing the impeller and housing.
  5. Install the new oil drain plug seal and gearcase drain seals, then refill with the correct specification oils.
  6. Reconnect the battery and test the engine in a well-ventilated area to ensure proper operation.

Troubleshooting & FAQ

How do I confirm this kit fits my specific engine?

This kit is for Mercury 15-20 HP EFI 4-Stroke outboards made from 2018-present with a serial number of 0R833820 or higher. Always verify your engine's model, year, and serial number before ordering.

What is the recommended service interval for this kit?

As the name suggests, this is a 300-hour service kit. It should be used every 300 hours of operation or every three years, whichever comes first, as part of your engine's preventative maintenance schedule.

What are the signs that my engine needs this service?

Beyond the scheduled interval, signs of failing components can include poor engine performance, difficulty starting, rough idling (clogged filters or fouled plugs), or engine overheating (worn water pump impeller).

Are all gaskets, seals, and anodes included?

Yes, this kit includes the essential seals for the oil and gearcase drains, as well as the lower unit and power tilt anodes required for a standard 300-hour service.

Can I install this kit myself?

While installation is possible for those with mechanical experience, we recommend professional installation to ensure all components are fitted correctly, torqued to spec, and the engine functions safely.

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.

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