Water Pump Impeller – Fits Mercury/Mariner 3.5-9.8HP Outboards (Replaces 47-22748)

Water Pump Impeller – Fits Mercury/Mariner 3.5-9.8HP Outboards (Replaces 47-22748)

This water pump impeller is designed for a range of 2-stroke Mercury and Mariner outboards from the 1960s to the 1980s, covering models from 3.5 HP to 9.8 HP. Fitment is determined by specific engine serial number ranges, so please verify your engine's details before ordering.

This component is a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 47-22748, Sierra 18-3012, Mallory 9-45308, GLM 89600, SEI Marine 96-299-03C, and CEF 500309.

• Installation Type: Direct OEM replacement with a press fit onto the driveshaft.
• Core Materials: Constructed from a durable neoprene rubber compound with a brass/metal alloy hub for corrosion resistance and longevity.
• Key Design: Features 6 rubber blades (vanes) designed to meet original equipment specifications for flow and pressure.

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 47-22748)

Installation Guide

1. Disconnect the battery and shift linkage.
2. Unbolt and carefully remove the lower unit (gearcase) from the outboard leg.
3. Locate the water pump assembly on top of the lower unit and remove its housing bolts.
4. Lift off the housing and remove the old impeller, taking note of the original orientation of the vanes.
5. Clean any debris or corrosion from the inside of the housing and wear plate.
6. Install the new impeller by sliding it onto the driveshaft. Turn the shaft clockwise while pushing down to help bend the vanes into the correct position inside the housing.
7. Reassemble the water pump housing, ensuring any gaskets or seals are correctly seated.
8. Reinstall the lower unit, reconnect all linkages, and test the engine on a water supply to confirm proper water flow from the telltale outlet.

Troubleshooting & FAQ

Q: How do I confirm this fits my engine?

A: Check the compatible models table on this page. It is crucial to match your engine's model, horsepower, and especially its serial number (S/N) with the listed applications. The serial number is the most reliable way to confirm fitment for these vintage Mercury engines.

Q: What are the signs of a failing water pump impeller?

A: Common signs include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "telltale" outlet, and finding cracked, brittle, or broken rubber vanes on the old impeller during inspection.

Q: How often should I replace my impeller?

A: For optimal engine protection, 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 operating in saltwater or in water with heavy sediment.

Q: What is the difference between this impeller and the original Mercury part?

A: This is an aftermarket part designed to meet or exceed OEM specifications for fit, form, and function. It is made from a high-quality neoprene and brass alloy, providing a reliable and cost-effective alternative to the original 47-22748 impeller.

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.