Water Pump Impeller Kit – Fits Mercury/Mariner Outboard 30–70 HP 2-Stroke (Replaces 47-89983Q1, 47-89983T2)

Water Pump Impeller Kit – Fits Mercury/Mariner Outboard 30–70 HP 2-Stroke (Replaces 47-89983Q1, 47-89983T2)

This water pump impeller repair kit is designed for Mercury and Mariner 2-stroke outboard engines ranging from 30 to 70 HP, covering models from approximately 1970 to 1997. It provides the necessary components to restore the engine's cooling system for reliable performance.

This kit is a direct replacement for multiple OEM and aftermarket part numbers, ensuring a precise fit and function. Please see the cross-reference table and engine compatibility list to verify fitment for your specific model and serial number.

• Engineered as a direct replacement for a straightforward installation.
• Restores cooling system performance to prevent engine overheating.
• Comprehensive nine-piece kit includes a new impeller, gaskets, seals, and related hardware.

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

This kit includes the following components for a complete water pump overhaul. Note: The full kit contains nine pieces, but exact contents can vary. Ensure the parts listed match your repair needs.

• 1 x Water Pump Impeller (Replaces Sierra 18-3007)
• 1 x Upper Pump Housing (Replaces Sierra 18-3118)
• 1 x Drain Gasket (Replaces Sierra 18-2945)
• 1 x Lower Water Pump Base To Face Plate Gasket (Replaces Sierra 18-2823)
• 1 x Upper Face Plate To Body Gasket (Replaces Sierra 18-2824)
• 1 x Water Pump Seal (Replaces Sierra 18-2825)
• 1 x Seal for drain/fill plugs
• 1 x Collar for water pump tube
• 1 x Coupler for water pump tube

Installation Guide

1. Disconnect Power: Disconnect the battery and spark plug wires for safety.
2. Drain Gearcase: Open the drain and vent screws to drain the gearcase lubricant.
3. Remove Lower Unit: Unbolt and carefully detach the lower unit (gearcase) from the outboard's midsection.
4. Access Water Pump: Unscrew the bolts securing the water pump housing to access the impeller.
5. Remove Old Components: Take note of the orientation of all parts. Remove the old impeller, housing, gaskets, and seals.
6. Clean Surfaces: Thoroughly clean all mating surfaces to ensure a proper seal.
7. Install New Kit: Install the new gaskets, face plate, impeller, and housing from the kit. Ensure the impeller key is correctly seated.
8. Reassemble: Re-install the water pump housing, ensuring bolts are torqued to spec.
9. Reattach Lower Unit: Reconnect the lower unit to the engine.
10. Test Operation: Re-fill the gearcase with new lubricant, reconnect the battery, and start the engine using a water supply (flushing muffs) to verify a strong water stream from the tell-tale.

Troubleshooting & FAQ

How do I confirm this kit fits my Mercury engine?
The most reliable method is to match your engine's serial number to the ranges listed in the "Compatible Engine Models" table. The serial number is typically found on a plate on the transom bracket. If you are unsure, consult the Mercury Serial Number Guide linked above.

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, or a melted water pump housing. Failure to replace a worn impeller can lead to severe engine damage.

How often should I replace the water pump impeller?
As a general maintenance item, it is recommended to inspect and/or replace the water pump impeller every 1 to 2 years, or every 100-200 hours of operation, depending on usage 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.