Complete Water Pump Housing Kit – Fits Mercury/Mariner 30-70 HP 2-Stroke (Replaces 46-73640A2)

$87.00 $139.00

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Complete Water Pump Housing Kit – Fits Mercury/Mariner 30-70 HP 2-Stroke (Replaces 46-73640A2) is backordered and will ship as soon as it is back in stock.

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You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This is a Complete Water Pump Housing Kit – Fits Mercury/Mariner 30-70 HP 2-Stroke (Replaces 46-73640A2), providing a comprehensive solution for servicing the cooling system on various outboards from 1970 to 1986. It covers models including the 30 Jet, 35, 40, 45, 50, and 60 HP engines, ensuring broad compatibility for older engine restoration and maintenance.

This kit serves as a direct aftermarket replacement for Mercury part 46-73640A2, Sierra 18-3323, and GLM 12180, offering an equivalent for multiple cross-referenced part numbers.

Installs as a direct replacement for the stock OEM housing.

Part Number Matrix

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

Brand	Part Number
Mercury	46-73640A2
Sierra	18-3323
GLM	12180

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This part is designed for Mercury, Mariner, and Force brand outboard engines within the specified horsepower and year ranges. Please check your serial number to ensure precise fitment.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury/Mariner	30 Jet	30	2-Stroke	1994–1997	46-73640A2	Serial Range: 0C159200-0G58999
Mercury/Mariner	35	35	2-Stroke	1984–1989	46-73640A2	Serial Range: 6445653-up
Mercury/Mariner	40	40	2-Stroke	1978–1983	46-73640A2	2-cylinder engines
Mercury/Mariner	40	40	2-Stroke	1989-up	46-73640A2	4-cylinder engines, Serial Range: 0C159200-up
Mercury/Mariner	45	45	2-Stroke	1986	46-73640A2	4-cylinder models
Mercury/Mariner	45 Jet	45	2-Stroke	1994–1995	46-73640A2	Serial Range: 0D000750-up
Mercury/Mariner	50	50	2-Stroke	1970–1986	46-73640A2	4-cylinder engines with plastic water pumps
Mercury/Mariner	50	50	2-Stroke	1976–1979	46-73640A2	Made in USA, Serial Range: 4357640-5531629
Mercury/Mariner	50	50	2-Stroke	1976–1979	46-73640A2	Made in AUS, Serial Range: 8030090-8063984
Mercury/Mariner	50	50	2-Stroke	1976–1979	46-73640A2	Made in BEL, Serial Range: 9107214-9248005
Mercury/Mariner	50	50	2-Stroke	1976–1979	46-73640A2	Made in CAN, Serial Range: 7068998-7143687
Mercury/Mariner	50	50	2-Stroke	1986–1987	46-73640A2	3-cylinder engines, Serial Range: 6428681-0D000749 (USA)
Mercury/Mariner	60	60	2-Stroke	1984–1987	46-73640A2	Serial Range: 6428681-0D000749 (USA), 9385911-9683054 (BEL), 7208333-up (CAN)
Mercury/Mariner	70	70	2-Stroke	1977–1979	46-73640A2	Made in USA, Serial Range: 4571652-4977156
Mercury/Mariner	70	70	2-Stroke	1977–1979	46-73640A2	Made in AUS, Serial Range: 8042350-8050199
Mercury/Mariner	70	70	2-Stroke	1977–1979	46-73640A2	Made in BEL, Serial Range: 9135825-9196960
Mercury/Mariner	70	70	2-Stroke	1977–1979	46-73640A2	Made in CAN, Serial Range: 7087823-7110997
Mercury/Mariner	70	70	2-Stroke	1977–1983	46-73640A2	Serial Range: 4977157-6428680 (USA), 8050200-up (AUS), 9196961-9385910 (BEL), 7110998-7208332 (CAN)

Technical Specs

Product Type: Water Pump Housing Kit
Installation: Direct replacement for OEM housing
Dimensions: Length: 4.5 in, Width: 2.63 in, Height: 4.88 in
Weight: 0.27 kg (0.60 lb)

Installation Notes

Disconnect the battery and spark plug leads for safety.
Place a drain pan under the lower unit and remove the gear lube drain/vent screws to empty the oil.
Remove the bolts securing the lower unit (gearcase) to the upper driveshaft housing.
Carefully lower the gearcase assembly to access the water pump.
Unbolt and remove the old water pump housing and impeller assembly.
Clean the mounting surfaces and inspect the driveshaft for wear or damage.
Install the new gaskets, wear plate, impeller, and housing provided in the kit.
Apply a light coat of marine grease to the interior of the housing and impeller.
Reinstall the lower unit, ensuring the water tube and shift shaft are correctly aligned.
Tighten all bolts to the manufacturer's specified torque.
Refill the gearcase with fresh marine gear lube until it emerges from the upper vent hole.
Reconnect the battery and test the engine on a water supply to verify proper cooling system function.

Troubleshooting & FAQ

How do I confirm this kit fits my exact engine model?

The most reliable method is to match your engine's serial number to the ranges listed in the compatibility table. While the kit fits many 30-70 HP models from 1970–1986, serial number breaks are critical for ensuring perfect fitment.

What are common signs that my water pump housing needs replacement?

Key indicators include the engine overheating at low speeds, a weak or non-existent water stream from the "telltale" outlet, and visible signs of damage like cracks, warping, or melting on your existing plastic housing.

How often should I service my outboard's water pump?

For preventative maintenance, it is best practice to inspect the water pump impeller and housing annually. We recommend a full replacement every 2-3 years or 200-300 operating hours, whichever comes first, especially if you operate in saltwater or sandy/silty conditions.

Should I replace the impeller at the same time as the housing?

Absolutely. It is highly recommended to replace the impeller, wear plate, gaskets, and seals whenever the housing is serviced. This ensures the entire system is refreshed for reliable, long-lasting performance and prevents a premature failure of older components.

Is this an OEM or aftermarket part?

This listing is an aftermarket replacement (not OEM). It has been engineered to meet or exceed OEM-level specifications using comparable, high-quality materials. All parts are produced in an ISO 9002 certified facility and are batch-inspected for quality and consistency.

What are the shipping speed and cost?

We ship worldwide quickly—typical transit is 5–15 days for most regions. Standard shipping is free. Expedited shipping options, if available for your location, will be presented at checkout.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order number. Returns are accepted within our standard window for items that are unused and in their original packaging. See our full 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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