47-803631T Water Pump Impeller for Mercury Mercruiser Force | JLM Marine

Water Pump Impeller for Mercury Mercruiser Force (47-803631T)

This aftermarket water pump impeller is designed to fit a wide range of Mercury, Mercruiser, and Force outboard engines from 75 HP to 225 HP. It suits Mercury Mariner L4, L6, and V6 engines, Mercruiser MC-I and MR/Alpha One gear housing components, as well as Force outboard motors rated 75–150 HP. Whether you're servicing a vintage motor or a newer model, this impeller provides reliable cooling system performance for multiple applications.

This impeller directly replaces Mercury part numbers 47-803631T, 47-89984T4, 47-F694065, 47-30221, 47-89984, and 47-65960, ensuring broad compatibility across decades of marine engine production.

• Features a 6-blade design with brass hub for durability and corrosion resistance
• Compact dimensions: 33.60 mm height, 59.60 mm external diameter, 22.40 mm internal shaft diameter
• Includes one outboard impeller ready for installation

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 Impeller

Installation Guide

1. Disconnect the fuel line and ensure the engine is turned off and cool. Remove the lower unit according to your engine's service manual.
2. Access the water pump housing by removing the mounting bolts. Take note of the orientation of the old impeller before removal.
3. Carefully remove the old impeller, liner, and gaskets. Inspect the pump housing for wear, corrosion, or debris and clean thoroughly.
4. Lubricate the new impeller blades with water-resistant grease or glycerin. Do not use petroleum-based products.
5. Insert the new impeller into the pump housing, ensuring the blades face the correct direction (refer to your service manual for rotation direction).
6. Install a new liner and fresh gaskets. Align all components carefully to prevent leaks.
7. Reassemble the pump housing and secure it with mounting bolts torqued to manufacturer specifications. Reattach the lower unit.
8. Reconnect the fuel line and start the engine. Check for steady water flow from the tell-tale outlet to confirm proper pump operation.

Troubleshooting & FAQ

How do I confirm this impeller fits my engine?
Cross-reference your engine's serial number and model with the compatibility table above. You can also compare the original part number stamped on your old impeller with the numbers listed in the Part Number Cross-Reference section.

How often should I replace my water pump impeller?
Most manufacturers recommend replacing the impeller every 2–3 years or 200–300 operating hours, whichever comes first. If you operate in sandy, debris-filled, or saltwater environments, inspect it annually and replace at the first sign of wear.

What are the signs that my impeller is failing?
Common symptoms include weak or absent water flow from the tell-tale, engine overheating, steam from the engine, or reduced performance. If you notice any of these, shut down immediately and inspect the impeller.

Can I use this impeller in saltwater?
Yes, this impeller is suitable for both freshwater and saltwater applications. The brass hub provides corrosion resistance; however, regular maintenance and freshwater flushing after saltwater use will extend its lifespan.

What is the difference between this aftermarket impeller and the OEM part?
This aftermarket impeller is manufactured to meet or exceed OEM specifications using comparable-grade materials. It offers the same fitment and performance at a more competitive price point, without the OEM premium.

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.