Water Pump Impeller Kit – Fits Mercury/Mariner 9.9-25 HP (Replaces 46-99157T2, 85098A2, 99157A2)

Product Details

This Water Pump Impeller Kit – Fits Mercury/Mariner 9.9-25 HP (Replaces 46-99157T2, 85098A2, 99157A2) is a direct-fit replacement for various Mercury and Mariner outboard engines. It is designed for specific 2-Stroke 15–25 HP (1980–1997) and 4-Stroke 9.9–15 HP models, including BigFoot, Sea Pro, and Marathon editions.

This kit serves as a direct interchange for multiple part numbers, including Mercury 46-99157T2, 99157T2, 85098A2, and 99157A2, as well as aftermarket equivalents like Sierra 18-3320, GLM 12014, and Mallory 9-48300.

• Installs as a direct OEM-style replacement.
• The housing is constructed from durable stainless steel and ABS plastic.
• Manufactured in an ISO9002 certified facility for reliable quality.

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.

This kit is compatible with a range of Mercury and Mariner outboards. Verify your engine's serial number against the listed ranges to ensure a precise fit.

Technical Specs

Product Type

Water Pump Impeller Kit with Housing

Installation

Direct OEM replacement

Housing Material

Stainless steel and ABS plastic

Housing Color

Silver/gray

Warranty

1 year (varies by manufacturer)

Other Technical Attributes

ISO9002 certified factory (JLM Marine)

What’s in the Box

• 1 x Pump Housing Assembly (99157T2)
• 1 x Impeller (47-85089-3/47-85089-10)
• 2 x Impeller Washer (8M0027721)
• 1 x Impeller Key (8M0032838)
• 1 x Pump O-Ring (69202)
• 1 x Wear Plate (85083)
• 1 x Pump Gasket (85087/27-993261)
• 1 x Seal (85090001)
• 4 x Bushing (85095)
• Multiple O-rings, screws, and washers

Installation Notes

1. Disconnect the spark plug wires and shift the outboard into neutral.
2. Place a suitable container under the lower unit and drain the gearcase oil.
3. Remove the bolts securing the lower unit (gearcase) to the engine's midsection and carefully lower it.
4. Unbolt and remove the old water pump housing assembly from the driveshaft.
5. Clean any gasket residue from the mounting surfaces and inspect the driveshaft for wear.
6. Slide the new wear plate and gasket onto the driveshaft.
7. Install the new impeller key and slide the new impeller onto the shaft, turning it clockwise to align the vanes.
8. Install the new housing, O-rings, and seals as per the kit's components.
9. Lightly grease the bolts and tighten the housing to the manufacturer's specified torque.
10. Reinstall the lower unit, ensuring the water tube and shift shaft are properly aligned. Refill the gearcase with new oil.
11. Reconnect the spark plug wires. Start the engine in water and verify a strong, consistent water stream from the 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.
• Fast Global Fulfillment — Free standard delivery to most regions, typically arriving in 5–15 days.
• Manufacturer-Direct Value — Fair pricing is achieved by eliminating middlemen, without compromising on materials or quality control.