Water Pump Base Gasket – Fits Mercury/Mercruiser Outboard Motors (Replaces 27-32771)

$5.99

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Product Details

This is a high-quality aftermarket Water Pump Base Gasket – Fits Mercury/Mercruiser Outboard Motors (Replaces 27-32771), designed for various Mercury and Mercruiser outboard motors. It ensures a proper seal between the water pump base and the gear housing, which is critical for preventing leaks and maintaining cooling system integrity.

This component serves as a direct replacement for Mercury part numbers 27-32771 and 32771, as well as SEI Marine 95-264-02B.

Installs between the water pump base and gear housing.
Engineered to meet or exceed OEM material specifications for durability.
Prevents water leaks and protects internal gearcase components.

Part Number Matrix

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

Brand	Part Number
Mercury	27-32771
Mercury	32771
SEI Marine	95-264-02B

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury/Mercruiser Models: Please verify compatibility using your engine's serial number range as listed in the 'Years' column.

Brand	Model	Rated HP	Years	OEM Part No.
Mercury	350		1571114-1812753	27-32771
Mercury	350		1812754-1960826	27-32771
Mercury	350		1960827-2874703	27-32771
Mercury	400 (2 CYL.)		2874704-3336257	27-32771
Mercury	402		3336258-4117709	27-32771
Mercury	402		3339688-9076838	27-32771
Mercury	402		3340783-7047607	27-32771
Mercury	402		4117710-4860102	27-32771
Mercury	402		7047608-7112422	27-32771
Mercury	402		8002335-8027439	27-32771
Mercury	402		8027440-8052124	27-32771
Mercury	402		9076839-9184450	27-32771
Mercury	450 (4 CYL.)		1476510-1531568	27-32771
Mercury	500		1421113-1639472	27-32771
Mercury	500		1639473-1755548	27-32771
Mercury	500		1755549-2097444	27-32771
Mercury	500		1770179-2116317	27-32771
Mercury	500		2097445-2305100	27-32771
Mercury	500		2116318-2305100	27-32771
Mercury	500		2305101-2858813	27-32771
Mercury	500		2742142-7051982	27-32771
Mercury	500		2858814-4140999	27-32771
Mercury	500		2863739-8029514	27-32771
Mercury	500		4141000-4357639	27-32771
Mercury	500		7051983-7068997	27-32771
Mercury	500		8029515-8030089	27-32771
Mercury	500		9001581-9082513	27-32771
Mercury	500		9082514-9107213	27-32771
Mercury	500, 50	50	4357640-5531629	27-32771
Mercury	500, 50	50	7068998-7143687	27-32771
Mercury	500, 50	50	8030090-8063984	27-32771
Mercury	500, 50	50	9107214-9248005	27-32771
Mercury	650 (3 CYL.)		3293184-3525440	27-32771
Mercury	650 (3 CYL.)		3547987-4382056	27-32771
Mercury	650 (3 CYL.)		4382057-4571651	27-32771
Mercury	650 (3 CYL.)		7013633-7073472	27-32771
Mercury	650 (3 CYL.)		7073473-7087822	27-32771
Mercury	650 (3 CYL.)		8006640-8042349	27-32771
Mercury	650 (3 CYL.)		9020074-9112988	27-32771
Mercury	650 (3 CYL.)		9112989-9135824	27-32771
Mercury	70 (3 CYL.)	70	4571652-5579016	27-32771
Mercury	70 (3 CYL.)	70	7087823-7145937	27-32771
Mercury	70 (3 CYL.)	70	8042350-8065064	27-32771
Mercury	70 (3 CYL.)	70	9135825-9255130	27-32771

Technical Specs

Product Type: Water Pump Base Gasket
Installation: Between water pump base and gear housing
Shape: Round/Circular
Product Dimensions: Height: 6.0 in; Width: 7.5 in; Length: 1.06 in
Weight: Approximately 5 ounces (142g)
OEM Part Number: 27-32771
UPC: 745061135987
Warranty: Standard Mercury Marine factory warranty

What’s in the Box

1 x Gasket (27-32771)

Installation Notes

Disconnect the battery and ensure the engine is turned off and cool.
Remove the lower unit (gearcase) from the outboard motor.
Unbolt and carefully lift the water pump housing to expose the base.
Remove the old gasket, ensuring the mating surfaces on both the gear housing and pump base are completely clean of any old gasket material or sealant.
Place the new gasket onto the gear housing, aligning it with the bolt holes.
Reinstall the water pump base and housing, torquing the bolts to the manufacturer's specified values.
Reassemble the lower unit and test the engine's cooling system function in the water.

Troubleshooting & FAQ

How do I know if this gasket will fit my specific Mercury engine?

The most reliable method is to check your engine's serial number against the ranges provided in the compatibility table. If your serial number falls within one of those ranges for your model, this gasket is the correct fit.

What are the signs of a failing water pump base gasket?

Common signs include water leaking from the gearcase seams, an overheating engine at idle or low speeds, or a weak "telltale" stream. Water intrusion into the gearcase oil (milky gear lube) can also indicate a seal failure in this area.

Can I reuse my old gasket?

No. Gaskets are single-use components that compress to create a seal. Once removed, they will not provide a reliable seal and should always be replaced with a new one during water pump service.

Do I need to use sealant with this gasket?

Generally, these gaskets are designed to be installed dry. However, always consult your specific engine's service manual, as some models may recommend a light application of a non-hardening sealant.

How often should this gasket be replaced?

This gasket should be replaced every time you service your water pump impeller, which is typically recommended every 1-2 years or 100-200 hours of use, depending on operating conditions (especially in saltwater).

Is this an original Mercury Marine part?

This is an aftermarket replacement part, not an original equipment manufacturer (OEM) component. It is designed to be a direct replacement and meet the same performance standards as the original gasket.

What is the difference between OEM and aftermarket parts?

This listing is for an aftermarket replacement, not an OEM part. It is built to the same specifications with comparable materials in an ISO 9002 certified facility and is batch-inspected for quality and consistency.

How fast is shipping?

We ship worldwide, with most orders arriving in 5–15 days. Standard shipping is free, and expedited options are available at checkout where applicable.

What is the warranty and return policy?

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

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

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