Water Pump Impeller – Fits Mercury Mariner 3.5-9.8 HP (Replaces 47-89980, 47-68988)

Water Pump Impeller – Fits Mercury Mariner 3.5-9.8 HP (Replaces 47-89980, 47-68988)

This water pump impeller is designed for Mercury and Mariner 3.5, 3.6, 4, 4.5, 7.5, and 9.8 HP 2-stroke outboard motors manufactured between 1979 and 1986. It provides a reliable solution for maintaining your engine's cooling system for peak performance.

Engineered as a direct replacement for original parts, this impeller ensures seamless compatibility and restores your motor's cooling efficiency. It is built to meet or exceed OEM specifications for fit and function.

• Installation Type: Direct Replacement
• Material: High-durability Neoprene with a Brass/Metal Alloy Hub
• Package Includes: 1 x Water Pump Impeller

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 47-89980)

Explosion Diagram

Installation Guide

1. Disconnect the spark plug wires and shift the outboard into neutral.
2. Place a drain pan under the lower unit and remove the gearcase drain and vent screws to empty the gear lube.
3. Unbolt and carefully slide the lower unit (gearcase) off the driveshaft housing.
4. Locate and unbolt the water pump housing cover to expose the old impeller.
5. Note the rotational direction of the old impeller's blades before pulling it off the driveshaft.
6. Clean the housing and wear plate, inspecting for grooves, warping, or damage. Replace the housing if wear is significant.
7. Slide the new impeller onto the driveshaft, turning the shaft in its normal rotational direction (typically clockwise) to bend the vanes correctly inside the housing.
8. Reinstall the water pump housing, ensuring any gaskets or seals are properly seated. Tighten bolts to the manufacturer's specified torque.
9. Guide the lower unit back into place, aligning the driveshaft, shift shaft, and water tube. Reinstall and tighten mounting bolts.
10. Refill the gearcase with the recommended marine gear lubricant before starting the engine.

Troubleshooting & FAQ

How do I confirm this fits my engine?

The most reliable method is to match your engine's serial number to the ranges listed in the 'Compatible Engine Models' table. If your serial number is not listed or you are unsure, please contact us with your engine details before ordering.

What are the signs of a failing water pump impeller?

Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and a noticeably high engine temperature reading on your gauge.

How often should I replace my impeller?

For preventative maintenance, it is recommended to inspect your impeller annually and replace it every 1-2 years or every 100-200 hours of use, depending on operating conditions (e.g., saltwater vs. freshwater).

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.