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Water Pump Impeller – Fits Mercury/Mariner 6-15 HP, Force/Chrysler/US Marine 9.9-15 HP (Replaces 47-42038, 47-42038Q02, 18-3062)

Sale price $14.49 Regular price $23.00
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Water Pump Impeller – Fits Mercury/Mariner 6-15 HP, Force/Chrysler/US Marine 9.9-15 HP (Replaces 47-42038, 47-42038Q02, 18-3062) is backordered and will ship as soon as it is back in stock.


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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 is a direct replacement Water Pump Impeller for Mercury/Mariner 6-15 HP (Replaces 47-42038, 47-42038Q02) outboard motors. It is designed to fit a wide range of Mercury/Mariner 2-stroke and 4-stroke engines from 1986–2005, as well as select Force/Chrysler/US Marine 9.9 and 15 HP models from 1998 with a standard gearcase.

This impeller provides a reliable equivalent for Mercury 47-42038/47-42038Q02, Sierra 18-3062, Chrysler/Force/US Marine 47-42038-2, Mallory 9-45309, and HeuroFosh 18-3062, ensuring broad compatibility for your marine cooling system maintenance.

  • Engineered for direct-fit installation.
  • Made from durable, flexible neoprene rubber for longevity.
  • Features a 6-blade design with a plastic hub for efficient water flow.

Part Number Matrix

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

Brand Part Number
Mercury 47-42038
Mercury 47-42038Q02
Chrysler/Force/US Marine 47-42038-2
Sierra 18-3062
Mallory 9-45309
HeuroFosh 18-3062

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury/Mariner engines, verify your model and serial number range against the tables for 2-stroke and 4-stroke outboards.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Mercury - 6 2-Stroke 1986–1993 47-42038 Serial: 0A197112-0T800749
Mercury - 8 2-Stroke 1986–1993 47-42038 Serial: 0A197112 & Up
Mercury - 9.9 2-Stroke 1986–1998 47-42038 Serial: 0A197112 & Up
Mercury XR10, Sea Pro, 10 Mag. & Marat 10 2-Stroke 1990–1998 47-42038 Serial: 0D038000 & Up
Mercury - 15 2-Stroke 1988–1998 47-42038 Serial: 0B292414 & Up
Mercury 15 Sea Pro & Marathon 15 2-Stroke 1994–1998 47-42038 Serial: 0G044365 & Up
Brand Model Rated HP Stroke Years OEM Part No. Notes
Mercury - 8 4-Stroke Up to 2005 47-42038 Serial: 0P086824-0P400999
Mercury - (232cc) 8 4-Stroke 1995–1998 47-42038 Serial: 0G760300-0T178499
Mercury - (232cc) 8 4-Stroke - 47-42038 Serial: 0H017100-0H017349
Mercury - (323cc) 9.9 4-Stroke Up to 2004 47-42038 Serial: 0P075166-0P400999
Mercury - (232cc) 9.9 4-Stroke 1995–1998 47-42038 Serial: 0H000058-0H016909
Mercury - (323cc) 9.9 4-Stroke Up to 2005 47-42038 Serial: 0G760300-1B226999
Mercury International 13.5 4-Stroke - 47-42038 Serial: 0P134638 & Up
Mercury - 15 4-Stroke Up to 2005 47-42038 Serial: 0P9973100 & Up
Mercury - (323cc) 15 4-Stroke 1998 & Up 47-42038 Serial: 0G590000 & Up

For Force, Chrysler, and Sears engines, this part fits 1998 models with a standard gearcase.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Force - 9.9 - 1998 47-42038-2 Standard gearcase
Force - 15 - 1998 47-42038-2 Standard gearcase
Sears - 9.9 - 1998 47-42038-2 Standard gearcase
Sears - 15 - 1998 47-42038-2 Standard gearcase

Technical Specs

Product Type
Water Pump Impeller
Installation
Direct replacement
Material
Neoprene rubber
Hub Type
Plastic
Number of Blades
6
Dimensions
External Diameter: 58.7 mm (2 5/16"), Internal Shaft Diameter: 12.7 mm (1/2"), Height: 11.5 mm (29/64")
Weight
11 g (0.35 oz)
Color
Black
Application
Marine outboard cooling system

What’s in the Box

  • 1 x Impeller (47-42038/47-42038Q02)
  • 1 x Drive Key (28-42376A2) (Note: included in some packages, not guaranteed)

Installation Notes

  1. Disconnect the battery and remove the engine cover.
  2. Drain the gearcase oil from the lower unit.
  3. Unbolt and carefully lower the gearcase from the outboard's upper section.
  4. Locate and unbolt the water pump housing cover to expose the old impeller.
  5. Take note of the old impeller's blade orientation, then remove it and the drive key.
  6. Clean the housing and inspect it for wear, corrosion, or debris.
  7. Lightly lubricate the new impeller and housing interior with marine grease.
  8. Install the new drive key and slide the new impeller onto the driveshaft, turning the shaft clockwise to seat the blades.
  9. Reinstall the water pump housing, ensuring a proper seal.
  10. Reattach the lower unit to the engine, making sure the driveshaft and water tube align correctly.
  11. Refill the gearcase with the correct oil.
  12. Once fully assembled, start the engine in water and verify cooling water is discharging strongly from the tell-tale port.

Troubleshooting & FAQ

How do I know if this impeller fits my exact engine model?

The best way to ensure compatibility is to verify your engine's serial number against the ranges provided in the "Engine & Model Compatibility" tables. If your serial number falls within the specified range for your HP and year, this impeller should fit.

What are the signs of a failing water pump impeller?

Common signs include a weak or non-existent water stream from the "tell-tale" outlet, engine overheating alarms, and reduced engine performance. Visible signs on the old impeller include cracked, brittle, or missing blades.

How often should I replace my outboard's impeller?

As a general maintenance rule, it's recommended to replace the impeller every 1-2 years or every 100-200 hours of operation, whichever comes first. This interval can be shorter if you frequently operate in sandy or silty water.

Does this impeller come with a drive key?

Some packages include the drive key, but it is not guaranteed. Please be prepared to reuse your existing key if it's in good condition or purchase one separately if needed.

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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