Water Pump Impeller – Fits Mercury/Mariner 6-15 HP (Replaces 47-42038, 47-42038Q02)

Water Pump Impeller – Fits Mercury/Mariner 6-15 HP (Replaces 47-42038, 47-42038Q02)

This water pump impeller is designed for a wide range of Mercury/Mariner 6, 8, 9.9, 10, 13.5, and 15 HP outboard motors (2-stroke and 4-stroke) manufactured between 1986 and 2005. It also fits select Force/Chrysler/US Marine 9.9 and 15 HP models from 1998 with a standard gearcase.

As a direct replacement part, this impeller meets or exceeds OEM specifications, ensuring reliable performance for your engine's cooling system. It is a direct substitute for Mercury parts 47-42038 and 47-42038Q02.

• Engineered for direct, hassle-free installation.
• Constructed from durable neoprene rubber for longevity and performance.
• The package includes one impeller. A drive key may be included but is not guaranteed in all packages.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Mercury/Mariner 2-Stroke Outboard Engines

Mercury/Mariner 4-Stroke Outboard Engines

Force/Chrysler/US Marine Outboard Engines

Technical Specifications

Package Contents

• 1 x Impeller (Replaces 47-42038/47-42038Q02)
• 1 x Drive Key (Replaces 28-42376A2) (Note: Drive key may not be included in all packages; please verify contents upon receipt.)

Installation Guide

1. Disconnect the spark plug leads and the battery for safety.
2. Place the outboard motor in a stable, upright position.
3. Locate the lower unit (gearcase) and place a drain pan underneath it.
4. Remove the gearcase drain and vent screws to drain the gear oil completely.
5. Unbolt the lower unit from the midsection of the engine. There are typically several bolts on the sides and one under the trim tab.
6. Carefully separate and lower the gearcase to expose the driveshaft and water pump housing.
7. Remove the bolts securing the water pump housing cover, then lift the cover off.
8. Pry or pull the old impeller off the driveshaft. Note the direction the vanes are bent.
9. Clean the inside of the pump housing and wear plate, inspecting for deep grooves or corrosion.
10. Align the new drive key and slide the new impeller onto the driveshaft. Twist it in the direction of engine rotation to seat the vanes correctly.
11. Reassemble the water pump housing, ensuring gaskets are properly seated, and torque bolts to specifications.
12. Reinstall the lower unit, refill with fresh gear oil, and reconnect the spark plug leads and battery before testing.

Troubleshooting & FAQ

How do I confirm this impeller fits my Mercury engine?
Check the compatibility tables for your engine model, HP, and year range. For Mercury engines, it is crucial to also match your engine’s serial number with the ranges specified in the tables to ensure an exact fit.

What are the signs of a failing water pump impeller?
Common signs include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and visible cracks, stiffness, or missing blades on the impeller upon inspection.

How often should I replace my outboard's impeller?
For preventative maintenance and to avoid overheating, we recommend inspecting the impeller annually and replacing it every 1-2 years or every 100-200 hours of use, whichever comes first. Service intervals may shorten in silty or saltwater environments.

My package didn't include a drive key. Is it required?
Yes, the drive key is a critical part that locks the impeller to the driveshaft, allowing it to spin. While some of our kits include it, others may not. If your old key is worn or lost, you must source a new one separately. Reusing the old key is possible if it's in good condition.

OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.