Water Pump Impeller Repair Kit – Fits Mercury/Mariner 3.9-9.8 HP (Replaces 46-92970A5, 47-89980T1)

Product Details

This Water Pump Impeller Repair Kit is designed for Mercury/Mariner 2-stroke outboard engines including 3.9, 4, 4.5, 6, 7.5, and 9.8 HP models from 1975–1986. Fitment is specific to models with a 0.438" impeller insert, ensuring proper water circulation to prevent overheating.

It serves as a direct replacement for Mercury part numbers 46-92970A5, 47-89980T1, and 47-89980Q1, and is interchangeable with QuickMarine 92970A5.

• Installs in the lower unit gearcase to restore cooling system performance.
• Features a durable Marine Grade Nylon PA66 housing and a Stainless Steel SS316 wear plate for corrosion resistance.
• The critical impeller insert size of 0.438 inches is precision-matched for a secure fit on the driveshaft.

Part Number Matrix

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

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury/Mariner engines, it is critical to verify your engine's serial number against the ranges provided to ensure accurate fitment. The manufacturing location (e.g., USA, BEL, CAN, AUS) often determines the correct serial number range.

Technical Specs

Product Type

Water Pump Impeller Repair Kit

Installation

Lower Unit Gearcase

Connection

Direct Fit

Housing Material

Marine Grade Nylon PA66 Water Pump Housing, Stainless Steel SS316 Wear Plate & Liner

Housing Color

Black

Weight

159 g (5.6 oz)

Fitting Type

Direct Replacement

Impeller Insert Size

0.438 inch (11.13 mm)

Warranty

1 Year (candy-marine eBay seller)

What’s in the Box

• 1 x Water Pump Housing
• 1 x Cover Assembly
• 1 x Face Plate (Wear Plate)
• 1 x Water Pump Impeller (47-89980T1)
• 1 x Cup Insert
• 1 x Key (Woodruff Impeller)
• 1 x Seal
• 2 x O-Ring
• 1 x Rubber Ring
• 1 x Oil Seal/O-Ring
• 1 x Washer

Installation Notes

1. Disconnect the battery and shift the outboard into the neutral position.
2. Place a drain pan under the lower unit and remove the drain plugs to empty the gearcase oil.
3. Remove the bolts that secure the lower unit (gearcase) to the upper leg assembly.
4. Carefully lower the gearcase away from the engine, paying attention to the shift shaft.
5. Unbolt and remove the old water pump housing assembly from the lower unit.
6. Thoroughly clean the driveshaft, splines, and all mounting surfaces.
7. Install the new components from the kit, starting with the Woodruff key and impeller. Ensure the impeller vanes are oriented correctly (typically clockwise).
8. Assemble the new housing, wear plate, and seals. Torque the bolts to the manufacturer's specified values.
9. Carefully reinstall the lower unit, making sure the driveshaft, water tube, and shift shaft are correctly aligned.
10. Refill the gearcase with fresh marine gear oil to the proper level.
11. Test the engine using a water supply (flushing muffs) and verify a strong, steady stream from the water pump tell-tale outlet.

Troubleshooting & FAQ

Safety & Important Info

• Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
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