Water Pump Impeller – Fits Mercury 3.9-9.8 HP Outboards (Replaces 47-89981)

Vendor: JLM Marine
Availability: In Stock
Product Type: Water Pump Impeller
$20.50
$20.50
Subtotal: $20.50

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Water Pump Impeller – Fits Mercury 3.9 - 9.8 HP Outboards (Replaces 47 - 89981) - JLM Marine Boat Parts Limited

Water Pump Impeller – Fits Mercury 3.9-9.8 HP Outboards (Replaces 47-89981)

$20.50

Water Pump Impeller – Fits Mercury 3.9-9.8 HP Outboards (Replaces 47-89981)

$20.50

Water Pump Impeller – Fits Mercury 3.9-9.8 HP Outboards (Replaces 47-89981)

This aftermarket water pump impeller is designed for Mercury 1-cylinder outboards, including 4 HP (1982-1985), 4.5 HP (1980-1985), 7.5 HP (1979-1986), and 9.8 HP (1979-1985) 2-Stroke models. It is built specifically for engines that use a 0.456" diameter driveshaft.

It serves as a direct replacement for Mercury OEM parts 47-89981, 47-89981Q1, 47-89981T1, and 47-89981T2, as well as other aftermarket equivalents, ensuring reliable performance for your engine's cooling system.

  • Material: Constructed from durable neoprene rubber with a solid brass hub to resist corrosion in marine environments.
  • Critical Fitment: Intended only for models with the 0.456" outer diameter driveshaft. Please verify your engine's requirements before purchase.
  • Package Includes: 1 x Water Pump Impeller.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Brand Part Number
Mercury 47-89981
Mercury 47-89981Q1
Mercury 47-89981T1
Mercury 47-89981T2
Sierra 18-3039
GLM 12270
GLM 89810
Mallory 9-45305
SEI Marine 96-260-03B

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.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Mercury 1-cylinder 4 2-Stroke 1982-1985 47-89981 S/N 2498136-4107219
Mercury - 4.5 2-Stroke 1980-1985 47-89981 S/N 4107220 and up
Mercury - 7.5 2-Stroke 1979-1986 47-89981 S/N 4131610 and up
Mercury (Model 110) 9.8 2-Stroke 1979-1985 47-89981 S/N 1865779 and up

Technical Specifications

Specification Value
Product Type Water Pump Impeller
Material Neoprene rubber with brass hub
Number of Blades 6
Impeller Height 11.6 mm (0.456 inch)
Overall Diameter 32 mm (1.260 inch)
Shaft Diameter 14.4 mm (0.567 inch)
Driveshaft Size 0.456 inch outer diameter
Weight 10 g (0.022 lb)
Warranty 1 Year (aftermarket)

Package Contents

  • 1 x Water Pump Impeller (Replaces 47-89981)

Installation Guide

  1. Disconnect the negative battery cable and shift the outboard into the neutral position.
  2. Locate and unbolt the lower unit (gearcase) from the engine's driveshaft housing.
  3. Carefully lower and separate the gearcase to expose the water pump assembly.
  4. Remove the bolts on the water pump housing cover to access the old impeller.
  5. Take note of the blade orientation of the old impeller before pulling it off the driveshaft.
  6. Clean any dirt or corrosion from the pump housing and inspect the wear plate and housing for damage.
  7. Slide the new impeller onto the driveshaft, ensuring the blades are bent in the correct rotational direction (usually clockwise).
  8. Reinstall the water pump housing cover and its gasket, tightening the bolts to the specified torque.
  9. Reattach the lower unit to the upper engine casing, ensuring the driveshaft and water tube align correctly.

Troubleshooting & FAQ

Q: How do I know if this impeller fits my Mercury engine?

A: This impeller is specifically for Mercury models from 3.9 HP to 9.8 HP that have a 0.456-inch diameter driveshaft. Please measure your driveshaft or verify your OEM part number is 47-89981 before ordering. It is crucial to confirm this dimension, as a different impeller exists for other models.

Q: Will this fit my 5 HP Mercury outboard?

A: No, this part will not fit 5 HP Mercury/Mariner engines, which typically require part number 47-16154-3.

Q: What are the signs that my water pump impeller needs replacing?

A: Common signs include a weak or non-existent water stream from the "telltale" outlet, engine overheating alarms, or visible damage such as cracked, stiff, or broken blades on the existing 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.

We can ship to virtually any address in the world with free shipping available for most regions.

For our typical US and Canadian customers , our shipping timeframes are as follows:

  • Amazon FBA: orders will be delivered within 1-5 business days after placing the order (during certain special periods such as major promotions, Christmas, etc., the delivery time of Amazon FBA may be affected).
  • US warehouse shipment: orders will be delivered within 5 days after placing the order.
  • China warehouse shipment: orders will be delivered about 12 days after placing the order.

When you place an order, we will estimate shipping and delivery dates for you based on the availability of your items and the shipping options you choose. Depending on the shipping provider you choose, shipping date estimates may appear on the shipping quotes page.

Please also note that the shipping rates for many items we sell are weight-based. The weight of any such item can be found on its detail page. To reflect the policies of the shipping companies we use, all weights will be rounded up to the next full pound.

Founded in 2002, JLM Marine has established itself as a dedicated manufacturer of high-quality marine parts, based in China. Our commitment to excellence in manufacturing has earned us the trust of top marine brands globally.

As a direct supplier, we bypass intermediaries, which allows us to offer competitive prices without compromising on quality. This approach not only supports cost-efficiency but also ensures that our customers receive the best value directly from the source.

We are excited to expand our reach through retail channels, bringing our expertise and commitment to quality directly to boat owners and enthusiasts worldwide.

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