47-22748 Outboard Rubber Impeller with Key/Pin for Mercury Mariner 2-S 3.5 3.9 5 6HP | JLM Marine

47-22748 Outboard Rubber Impeller with Key/Pin for Mercury Mariner 2-Stroke 3.5 3.9 5 6HP | JLM Marine

This high-quality aftermarket rubber impeller is engineered to fit Mercury Mariner 2-stroke outboard engines rated at 3.5, 3.9, 5, and 6 HP. Designed to deliver reliable water pump performance, this impeller ensures efficient cooling to protect your engine from overheating and extends service life.

A direct replacement for OEM part number 47-22748, this impeller meets or exceeds factory specifications for durability and fit. It is an essential maintenance component for keeping your outboard running smoothly season after season.

• Complete with key/pin for straightforward installation
• Precision-molded rubber construction for consistent water flow
• Compatible with Mercury Mariner 2-stroke small outboards

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 × Outboard Rubber Impeller
• 1 × Key/Pin

Installation Guide

1. Disconnect the fuel line and ensure the engine is off and cool before beginning work.
2. Remove the lower unit from the outboard motor by loosening the mounting bolts. Refer to your engine manual for specific procedures.
3. Locate and remove the water pump housing cover by unscrewing the fasteners. Keep all hardware organized for reassembly.
4. Extract the old impeller carefully, noting the direction of the blade curvature for proper installation of the new part.
5. Clean the pump housing thoroughly to remove any debris, old gasket material, or buildup that could impair the new impeller's performance.
6. Lubricate the new impeller blades with a water-resistant marine grease to ease installation and prevent damage during initial startup.
7. Insert the key/pin into the impeller hub slot to ensure proper alignment with the drive shaft.
8. Install the new impeller into the housing, making sure the blades curve in the correct rotational direction and the key/pin is properly seated.
9. Reinstall the water pump housing cover and gasket, tightening fasteners evenly to the manufacturer's torque specifications.
10. Reattach the lower unit to the motor, ensuring all mounting bolts are secure and properly torqued.
11. Reconnect the fuel line and run the engine briefly in a test tank or on-water to confirm proper water flow from the tell-tale indicator.
12. Inspect for leaks around the pump housing and verify that cooling water is circulating correctly before returning to normal operation.

Troubleshooting & FAQ

How do I confirm this impeller fits my Mercury Mariner outboard?
Check the compatible engine models table above and cross-reference with your engine's rated horsepower and stroke type. You can also verify using your original OEM part number (47-22748) or consult the Mercury serial number guide and parts diagrams linked in the compatibility section.

How often should I replace the water pump impeller?
Marine experts recommend replacing the impeller every 2–3 years or every 200–300 hours of operation, whichever comes first. If you notice reduced water flow from the tell-tale, overheating, or visible blade damage, replace it immediately regardless of service interval.

What are the signs that my impeller is failing?
Common symptoms include weak or no water discharge from the tell-tale indicator, engine overheating, steam from the powerhead, or reduced performance. Inspect the impeller annually and replace if blades are cracked, torn, or show significant wear.

Why is the key/pin included with this impeller?
The key (or pin) ensures the impeller is properly indexed and driven by the water pump shaft. It prevents slippage and guarantees correct rotational alignment. Always install the key/pin as shown in your service manual to avoid pump failure.

Can I install this impeller myself or do I need a mechanic?
If you have basic mechanical skills and the proper tools, you can replace the impeller following the installation steps provided. However, professional installation is recommended to ensure correct torque settings, gasket sealing, and alignment, especially if you are unfamiliar with lower unit service.

What is the difference between OEM and aftermarket impellers?
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.