Water Pump Repair Kit – Fits MerCruiser V6 & V8 Engines (Replaces 8M0142980, 47-8M0142980)

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Water Pump Repair Kit – Fits MerCruiser V6 & V8 Engines (Replaces 8M0142980, 47-8M0142980) is backordered and will ship as soon as it is back in stock.

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Product Details

This Water Pump Repair Kit – Fits MerCruiser V6 & V8 Engines is designed for the new generation of Mercury MerCruiser V6 (3.4L) and V8 (4.6L) 4-stroke engines (175-300 HP) from 2020 and newer models.

It serves as a direct aftermarket replacement for Mercury part numbers 8M0142980 and 47-8M0142980.

Engine-mounted, belt-driven installation.
Features the updated design for modern V6 (3.4L) & V8 (4.6L) engines.
Includes all necessary gaskets, seals, and impeller for a complete service.

Part Number Matrix

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

Brand	Part Number
Mercury	8M0142980
Mercury	47-8M0142980

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For MerCruiser engines, please verify your specific model and production year against this list.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
MerCruiser	V6 (3.4L)	175-300	4-Stroke	2020+	8M0142980
MerCruiser	V8 (4.6L)	175-300	4-Stroke	2020+	8M0142980

Technical Specs

Product Type: Water Pump Repair Kit
Installation: Engine-mounted, belt-driven
Weight: 3.2 oz (91 g)
Product Dimensions: 18.0" L x 10.5" W x 12.0" H
Other Technical Attributes: "NEW" design for 175-300 HP V6 (3.4L) & V8 (4.6L) engines

What’s in the Box

1 x Water pump gasket
1 x Face plate
1 x Face plate gasket
1 x Key
1 x Impeller
1 x Face seal
1 x Drain plug seal
1 x Water pump gasket
1 x O-ring
1 x Actuator seal
1 x Face seal tool

Installation Notes

Disconnect the battery and ensure the engine is completely cool before starting.
Relieve any pressure in the cooling system and have a container ready to catch draining coolant.
Locate the seawater pump assembly on the engine.
Loosen the serpentine belt tensioner and remove the belt from the pump pulley.
Disconnect the inlet and outlet hoses from the pump.
Carefully unbolt and remove the old pump assembly from its mounting bracket.
Thoroughly clean the mounting surface on the engine, ensuring no old gasket material remains.
Assemble the new kit components, including the impeller, gaskets, and seals, into the housing.
Mount the new water pump assembly and torque the mounting bolts to the manufacturer's recommended specification.
Reconnect the water hoses and reinstall the serpentine belt, verifying correct tension.
Refill the cooling system with the specified coolant type.
Reconnect the battery, start the engine, and meticulously check for any leaks and proper water flow.

Troubleshooting & FAQ

Which MerCruiser engines is this kit for?

This kit is specifically designed for the "NEW" MerCruiser V6 (3.4L) and V8 (4.6L) 4-stroke engines (175-300 HP) manufactured from 2020 onward.

Is this a complete kit for the repair?

Yes, it includes the impeller, face plate, gaskets, seals, and other necessary components for a standard water pump service. Refer to the "What’s in the Box" section for a full list of contents.

What are signs my water pump is failing?

Common symptoms include engine overheating at idle or low speeds, a steady drip of coolant or water from the pump's weep hole, or a grinding/whining noise emanating from the pump area.

How often should the water pump impeller be replaced?

For optimal reliability, most marine mechanics recommend inspecting the impeller annually and replacing it every 2–3 years or 200–300 service hours, depending on operating conditions (especially in saltwater or high-debris environments).

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

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.

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