Water Pump Impeller Kit for Mercury/Mariner 3.5–9.8 HP 2-Stroke Outboards — Replaces 47-89980T1 and 47-89980Q1

Product Details

This Water Pump Impeller Kit is intended for selected Mercury and Mariner 2-stroke outboards from 3.5 to 9.8 HP. The listed applications cover models manufactured between 1975 and 1986 and require an impeller with a 0.438-inch hub diameter. Always confirm the complete engine model, production year, and serial number before ordering.

This aftermarket replacement kit is listed for use in place of Mercury 47-89980T1 and 47-89980Q1, Sierra 18-3006, GLM 700-12271, and SEI 96-260-03AK references.

• Designed as a direct replacement for the specified water-pump applications.
• Neoprene rubber impeller provides dependable water flow through the raw-water cooling system.
• Kit includes the impeller, outer plate, key, guide sleeve, seal, and O-rings for a complete water-pump service.

Part Number Matrix

Use the following references together with your engine model and serial number to confirm compatibility.

Engine & Model Compatibility

The applications below are the listed fitment range for this kit. Model, horsepower, stroke, year, manufacturing location, and serial range must be considered together. Do not rely on horsepower alone to confirm fitment.

Technical Specifications

Product Type

Water pump impeller kit

Installation

Direct replacement

Impeller ID

0.438 in. (11.13 mm)

Impeller OD

1.26 in. (32 mm)

Impeller Height

0.57 in. (14.4 mm)

Number of Blades

6

Material

Neoprene rubber impeller

Housing Color

Black

Operating Temperature

Up to 105°C (221°F)

Application

Raw-water cooling systems in the specified marine engines

What’s in the Box

• 1 × Water pump impeller, reference 47-89980
• 1 × Cartridge outer plate, reference 46895
• 1 × Woodruff impeller key
• 1 × Water-inlet-tube guide sleeve
• 1 × Seal
• 2 × O-rings

Installation Notes

1. Disconnect the battery and remove the engine cover.
2. Place a drain pan under the lower unit and remove the gearcase oil drain screw to drain the oil.
3. Disconnect the shift linkage and remove the bolts securing the lower unit to the engine.
4. Carefully lower and remove the gearcase assembly.
5. Remove the water-pump housing to access the impeller, and note the orientation of the original parts.
6. Remove the old impeller, key, plate, and seals. Clean the mating surfaces thoroughly.
7. Install the replacement components in the reverse order of removal. Lightly lubricate the new impeller as appropriate for the installation.
8. Orient the impeller blades correctly inside the housing, typically by turning the driveshaft clockwise while lowering the housing.
9. Reinstall the water-pump housing and tighten the fasteners to the engine manufacturer’s specifications.
10. Reassemble the lower unit, reconnect the shift linkage, and refill the gearcase oil.
11. Reconnect the battery and test the engine in an appropriate water source to confirm proper water circulation.

Troubleshooting & FAQ

Safety & Important Information

• Verify the engine model, year, serial number, original part, dimensions, and key arrangement before purchase.
• Do not install the part if the original component differs from the listed specifications or fitment details.
• This is an aftermarket replacement part, not an original-equipment manufacturer component.
• Professional installation is recommended when you are not familiar with lower-unit or water-pump service.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts designed for demanding real-world conditions.
• Fast Global Fulfillment — Free standard delivery is available to most regions, with typical transit of 5–15 days.
• Manufacturer-Direct Value — Fair pricing supported by consistent materials and quality-control processes.