Water Pump Impeller Repair Kit – Fits Mercury 175–300 HP & 450R V6/V8 4-Stroke Outboards

Water Pump Impeller Repair Kit – Fits Mercury 175–300 HP & 450R V6/V8 4-Stroke Outboards

This water pump impeller repair kit is designed for Mercury Marine 4-stroke V6 (3.4L) and V8 (4.6L) outboards from 175 HP to 300 HP, including 450R racing engines. It is compatible with models that have serial numbers 2B529482 and above.

This kit serves as a direct replacement for Mercury OEM part numbers 47-8M0142980, 8M0205803, and 98-8M0142980, ensuring a precise fit and reliable performance for your engine's cooling system.

• Installation Type: Direct replacement for a straightforward installation.
• Durable Materials: Features a high-performance neoprene rubber impeller and marine-grade, corrosion-resistant metal components.
• Enhanced Performance: Engineered for improved flexibility across a wide range of temperatures, providing higher flow rates for superior cooling protection.

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.

Technical Specifications

Package Contents

• 1 x Water Pump Impeller (Replaces 47-89984Q5, 47-89984T5, 47-89984T6)
• 1 x Drive Key
• 1 x Gasket
• 1 x Wear Plate
• 1 x O-ring
• 1 x Face Seal
• 1 x Drain Plug Seal
• 1 x Water Pump Gasket
• 1 x Actuator Seal
• 1 x Face Seal Tool

Installation Guide

1. Disconnect the Battery: Ensure the engine is off and disconnect the battery terminals to prevent accidental starting.
2. Position the Engine: Tilt the outboard engine up to a convenient working height.
3. Drain Gearcase Lube: Place a drain pan under the lower unit and remove the upper and lower drain/vent screws to drain the gearcase lubricant.
4. Remove the Lower Unit: Remove the bolts securing the lower unit (gearcase) to the midsection. Carefully lower and separate it from the engine.
5. Access the Water Pump: With the lower unit removed, locate and unbolt the water pump housing to expose the impeller.
6. Inspect and Clean: Note the orientation of the old impeller fins. Remove the old impeller, gaskets, wear plate, and seals.
7. Install New Components: Clean all mating surfaces thoroughly. Install the new components from the kit in reverse order, ensuring the new impeller fins are oriented correctly.
8. Reassemble and Reinstall: Secure the water pump housing, then carefully guide the lower unit back into place, aligning the driveshaft and shift shaft.
9. Refill Gearcase Lube: Reinstall the lower unit bolts to the correct torque. Refill the gearcase with fresh lubricant until it seeps from the upper vent hole, then reinstall both screws.
10. Test Operation: Reconnect the battery. Start the engine using a water supply (flushing muffs) and check for a strong, steady stream from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my specific engine?

A: The most reliable way is to verify your engine's serial number. This kit fits Mercury V6/V8 models with a serial number of 2B529482 and newer. You can also match the OEM part numbers listed in our compatibility table (47-8M0142980/8M0205803) with your engine's service manual or parts diagram.

Q: What are the common signs that my water pump impeller needs replacement?

A: Telltale signs include your engine overheating, especially at low speeds or idle; a weak or inconsistent water stream from the "tell-tale" outlet port; or a lower-than-normal reading on your water pressure gauge.

Q: How often should I replace the water pump impeller?

A: For preventative maintenance, it is recommended to inspect it annually and replace it every 1 to 2 years or every 100-200 hours of operation. More frequent replacement may be necessary if you operate in saltwater or sandy/silty conditions.

Q: OEM vs. Aftermarket?

A: 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.

Q: How fast do you ship and how much does it cost?

A: 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.

Q: What is your warranty and return policy?

A: 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.