Water Pump Impeller Kit – Fits Mercury/Mariner 3.9–9.8 HP (Replaces 47-89980T1, 47-89980Q1)

Water Pump Impeller Kit – Fits Mercury/Mariner 3.9–9.8 HP (Replaces 47-89980T1, 47-89980Q1)

This water pump impeller kit is designed for Mercury/Mariner 3.5, 3.6, 3.9, 4, 4.5, 7.5, and 9.8 HP 2-Stroke outboards from 1975–1986. It is specifically compatible with engines that require a 0.438-inch impeller hub diameter.

This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 47-89980T1, Mercury 47-89980Q1, Sierra 18-3006, GLM 700-12271, and SEI 96-260-03AK.

• Engineered for a direct fit to simplify installation.
• Includes a high-quality neoprene impeller and all necessary seals and hardware for a complete overhaul.
• Designed for use in raw water cooling systems.

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 (47-89980)
• 1 x Cartridge Outer Plate (46895)
• 1 x Impeller Key, Woodruff
• 1 x Guide Sleeve, Water Inlet Tube
• 1 x Seal
• 2 x O-ring

Installation Guide

1. Safety First: Disconnect the engine's battery and remove the spark plug wires.
2. Access Lower Unit: Shift the outboard into neutral and remove the bolts securing the lower unit (gearcase) to the engine leg.
3. Remove Lower Unit: Carefully lower the gearcase away from the engine. The driveshaft will disengage from the powerhead.
4. Disassemble Pump: Locate the water pump housing on top of the gearcase. Remove the bolts to lift the housing off.
5. Inspect and Remove Old Parts: Take note of the old impeller's blade orientation. Remove the old impeller, gaskets, wear plate, and seals.
6. Clean Surfaces: Thoroughly clean the inside of the housing and the mounting surfaces, removing any old gasket material or debris.
7. Install New Components: Place the new gasket and wear plate. Insert the new woodruff key into the driveshaft slot.
8. Install New Impeller: Slide the new impeller onto the driveshaft. Turn the driveshaft clockwise while pushing down on the housing to correctly bend the impeller blades.
9. Reassemble Pump: Apply a light coat of marine grease to the inside of the housing. Reinstall the housing and tighten the bolts to the manufacturer's recommended torque.
10. Reinstall Lower Unit: Guide the driveshaft back into the powerhead, ensuring the water tube aligns correctly. Secure the lower unit with its bolts.
11. Test Operation: Reconnect the battery and spark plug wires. Start the engine in water and confirm a steady stream of water is exiting the tell-tale port.

Troubleshooting & FAQ

How do I confirm this fits my engine?
Check the "Compatible Engine Models" table. It is crucial to match your engine's brand, model, HP, year, and serial number range. This impeller is specifically designed for models requiring a 0.438-inch impeller hub diameter.

What are the signs that my impeller needs to be replaced?
Common signs of a failing impeller include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, or discovering brittle or broken pieces of rubber in the cooling system during inspection.

How often should I replace the water pump impeller?
As a general maintenance guideline, we recommend inspecting the impeller annually and replacing it every 1-2 years or every 100-200 hours of use. Replacement frequency should be increased if you operate primarily in sandy, silty, or saltwater conditions.

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.