47-22748 Water Pump Impeller for Mercury 2-Stroke 3.5HP 3.9HP 5HP 6HP | JLM Marine

Water Pump Impeller 47-22748 – Fits Mercury 2-Stroke 3.5HP 3.9HP 5HP 6HP Outboard Motors

This high-quality water pump impeller is engineered to fit Mercury 2-Stroke outboard motors rated at 3.5, 3.9, 5, and 6 horsepower. Designed to maintain optimal cooling performance, this neoprene impeller ensures reliable water circulation through your engine's cooling system, protecting your motor from overheating during operation.

This aftermarket replacement directly substitutes OEM part number 47-22748, as well as Sierra 18-3012 and Mallory 9-45308, providing a cost-effective solution without sacrificing quality or performance.

• Precision-molded neoprene construction for durability and resistance to wear
• Direct replacement for multiple OEM and aftermarket part numbers
• Compact design: 6 blades, 32mm external diameter, 11.6mm shaft insert diameter

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

Your purchase includes:

• 1 × Outboard Impeller (Neoprene, OEM P/N# 47-22748)

Installation Guide

1. Disconnect the fuel line and ensure the engine is off and cooled down completely.
2. Remove the lower unit from the outboard motor according to your engine's service manual.
3. Locate the water pump housing and carefully remove the retaining bolts or screws securing the pump cover.
4. Remove the old impeller by gently pulling it off the drive shaft; note the orientation of the blades.
5. Clean the pump housing thoroughly, removing any debris, old gasket material, or corrosion.
6. Lubricate the new impeller with marine-grade grease or glycerin to ease installation and protect the blades.
7. Install the new impeller onto the drive shaft, ensuring the blades are oriented in the correct rotation direction (typically the same as the old impeller).
8. Replace the pump housing gasket with a new one if available to prevent leaks.
9. Reassemble the pump cover and tighten all bolts evenly to the torque specifications in your service manual.
10. Reinstall the lower unit onto the outboard motor, ensuring all alignment marks and fasteners are properly secured.
11. Reconnect the fuel line and perform a visual inspection for proper assembly.
12. Test the engine in the water or with a flushing attachment to confirm water flow through the cooling system.

Troubleshooting & FAQ

Q: How do I confirm this impeller fits my Mercury outboard?
A: Cross-reference your engine's horsepower and serial number with the compatibility table above. If your serial number falls within the listed ranges for 3.5, 3.9, 5, or 6 HP 2-stroke Mercury motors, this impeller will fit. You can also verify using the Mercury parts diagrams linked in the compatibility section.

Q: How often should I replace my water pump impeller?
A: Most manufacturers recommend replacing the impeller every 2–3 years or every 200–300 hours of operation, whichever comes first. If you run in sandy, silty, or debris-laden water, inspect and replace more frequently.

Q: What are the signs that my impeller is failing?
A: Common symptoms include weak or no water discharge from the telltale (pee hole), engine overheating, steam from the powerhead, or a high-temperature alarm. If you notice any of these, inspect the impeller immediately.

Q: Can I install this impeller myself, or do I need a mechanic?
A: If you have basic mechanical skills and the right tools, you can install it yourself by following the service manual and the installation guide above. However, professional installation is recommended if you're unfamiliar with lower unit disassembly.

Q: What's the difference between OEM and aftermarket impellers?
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.