Water Pump Impeller Kit – Fits Mercury/Mariner 3.9–9.8 HP (Replaces 47-89980T1, 47-89980Q1)

Product Details

This Water Pump Impeller Kit is designed for a precise fit on Mercury and Mariner 2-stroke outboards from 3.5 to 9.8 HP, manufactured between 1975 and 1986. It is engineered for engines that require an impeller with a 0.438-inch hub diameter, ensuring reliable performance in raw water cooling systems.

This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 47-89980T1, 47-89980Q1, Sierra 18-3006, and GLM 700-12271.

• Engineered for direct-fit installation, simplifying maintenance.
• The neoprene rubber impeller provides durability and efficient water flow.
• Kit includes essential components like the outer plate, seals, and o-rings for a complete service.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.

Engine & Model Compatibility

Confirm your engine model and year in the table below to ensure correct fitment.

This kit fits a range of Mercury/Mariner outboards. Please verify your engine's serial number against the specified ranges to guarantee compatibility.

Technical Specs

Product Type

Water Pump Impeller Kit

Installation

Direct replacement

Impeller ID

0.438" (11.13 mm)

Impeller OD

1.26" (32 mm)

Impeller Height

0.57" (14.4 mm)

Number of Blades

6

Material

Neoprene rubber (impeller)

Housing Color

Black

Operating Temperature

Up to 105°C (221°F)

Other Technical Attributes

Designed for raw water cooling systems in specified marine engines

What’s in the Box

• 1 x Water Pump Impeller (47-89980)
• 1 x Cartridge Outer Plate (46895)
• 1 x Impeller Key, Woodruff
• 1 x Guide Sleeve, Water Inlet Tube
• 1 x Seal
• 2 x O-ring

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 empty 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. Unbolt and remove the old water pump housing to access the impeller. Note the orientation of the old parts.
6. Remove the old impeller, key, plate, and seals. Clean all mating surfaces thoroughly.
7. Install the new components from the kit in the reverse order of removal. Lightly grease the new impeller.
8. Ensure the impeller blades are oriented correctly inside the housing (typically by turning the driveshaft clockwise while pushing the housing down).
9. Reinstall the water pump housing and torque bolts to manufacturer specifications.
10. Reassemble the lower unit to the engine, reconnect the shift linkage, and refill the gearcase oil.
11. Re-connect the battery and test the engine in a water source to confirm proper water circulation.

Troubleshooting & FAQ

Safety & Important Info

• Verify images and specifications against your original part before purchase. If anything differs—even if your model appears compatible—do not install.
• This is an aftermarket replacement part, not an original equipment manufacturer (OEM) component.
• Professional installation is recommended for safety and optimal performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or quality control.