Water Pump Impeller Kit – Fits Mercury/MerCruiser V6/V8 4.3-8.2L (Replaces 47-8M0104229, 47-862232A2)

Product Details

This is a complete Water Pump Impeller Kit – Fits Mercury/MerCruiser V6/V8 4.3-8.2L (Replaces 47-8M0104229, 47-862232A2), designed for sterndrive engines equipped with brass sea water pumps. It is compatible with a wide range of V6 and V8 engines from 4.3L to 8.2L, manufactured from 2000 and newer, including Alpha, Bravo, MPI, and CARB variants.

This kit serves as a direct interchange for Mercury parts 47-862232A2 and 47-8M0104229, Sierra 18-3016-1, and Mallory 9-45310/9-45310-10.

• Engineered as a direct replacement for the OEM component.
• Constructed from durable neoprene rubber with a solid brass hub for corrosion resistance.
• Includes the impeller and essential O-ring for a complete service.

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 MerCruiser, this part fits a broad range of sterndrive and inboard engines with brass sea water pumps manufactured after 2000.

Technical Specs

Product Type

Water Pump Impeller Kit

Installation

Direct replacement for OEM component

Material

Neoprene rubber with brass hub

Application

For brass sea water pumps on MerCruiser engines

Impeller Diameter

66.5 mm (2.62 in)

Internal Shaft Diameter

15 mm (0.59 in)

Height

51 mm (2.01 in)

Weight

90.7 g (3.2 oz)

Country of Origin

Spain (Sierra brand)

Warranty

1 year against manufacturing defects (aftermarket)

What’s in the Box

• 1 x Impeller (Replaces 47-862232A2, 47-8M0104229)
• 1 x O-Ring (Replaces 25-841807)

Installation Notes

1. Disconnect the boat's battery and close the engine's water inlet seacock.
2. Locate and access the sea water pump housing.
3. Remove the screws securing the pump cover and carefully detach the cover plate.
4. Before removal, note the rotational direction of the existing impeller's blades.
5. Use impeller pullers or two flat-head screwdrivers to carefully pry out the old impeller.
6. Thoroughly clean the interior surfaces of the pump housing and the cover plate, removing any old gasket material or debris.
7. Lightly lubricate the new impeller and the inside of the housing with marine grease or liquid soap to prevent damage on first startup.
8. Install the new impeller by pushing it into the housing while turning it in the direction of engine rotation to correctly bend the blades.
9. Place the new O-ring in its groove on the pump body or cover.
10. Re-install the cover plate and tighten the screws in a star pattern to ensure an even seal.
11. Open the seacock, reconnect the battery, and start the engine. Immediately check the pump for any leaks and confirm water is flowing through the exhaust.

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 in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.