Water Pump Impeller Kit – Fits Mercury/Mercruiser 65-225 HP (Replaces 47-89984T3, 47-89984)

$15.99 $25.00

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Water Pump Impeller Kit – Fits Mercury/Mercruiser 65-225 HP (Replaces 47-89984T3, 47-89984) is backordered and will ship as soon as it is back in stock.

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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 Water Pump Impeller Kit provides a direct replacement for failing or worn impellers in a wide range of Mercury/Mercruiser 65-225 HP 2-Stroke outboards (from the 1960s to the 1990s), as well as Alpha One, MR, and pre-Alpha sterndrive units. It is also compatible with 65-225 HP Force/Chrysler outboards that use short-vane impellers. Engineered to restore cooling system efficiency, this kit ensures your engine maintains optimal operating temperature.

This component directly interchanges with Mercury parts 47-89984T3, 47-89984T4, and others, along with aftermarket equivalents from Sierra (18-3017), GLM (89840), and Mallory (9-45036).

Installation Method: Direct OEM replacement
Housing Material: Durable neoprene rubber with a corrosion-resistant brass hub insert
Included Essentials: Impeller, key, and gaskets for a complete service

Part Number Matrix

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

Brand	Part Number
Mercury	47-89984T3
Mercury	47-89984T4
Mercury	47-89984T5
Mercury	47-89984T6
Sierra	18-3017
Sierra	18-3517
GLM	89840
Mallory	9-45036
Mallory	9-48307

Engine & Model Compatibility

Confirm your engine model and year in the tables below.

For Mercury/Mercruiser Outboards: Check your model, HP, and serial number against the list to ensure fitment.

Model	Rated HP	Stroke	Years	Notes
65 HP (4 cylinder)	65	2-Stroke	1963–1976	Serial 1542745-3293183
70 HP	70	2-Stroke	1961–1967	Serial 1413611-1566239
75 HP (4 cyl)	75	2-Stroke	1984–1988	Serial 6432901 & UP
80 HP	80	2-Stroke	1969–1983	Serial 1355468-3493912
80 HP (4 cyl)	80	2-Stroke		Serial 4831999-6432900
85 HP (4 cyl)	85	2-Stroke	1973–1977	Serial 1460999-4831998
90 HP (6 cyl)	90	2-Stroke	1978–1986	Serial 4845301 & UP
95 HP (6 cyl)	95	2-Stroke	1966–1967	Serial 1869776-2318585
100 HP (6 cyl)	100	2-Stroke	1962–1969	Serial 1464949-3253111
105 HP JET	105	2-Stroke	1994–1995	Serial D182000 & UP
110 HP	110	2-Stroke		Serial 1870204-2314955
115 HP (6 cyl)	115	2-Stroke		Serial 2836019 & UP
125 HP	125	2-Stroke		Serial 2314956-3253111
135 HP V	135	2-Stroke		Serial 2839369-3293233
140 HP	140	2-Stroke		Serial 3293234 & UP
140 HP JET	140	2-Stroke	1994–1995	Serial D082000 & UP
150 HP	150	2-Stroke		Serial 3502806-4868647

For Mercruiser Sterndrives: Compatible with early MerCruiser I/R/MR and Alpha One drives through S/N 0D469858.

Model	Years	Notes
MerCruiser I (MC1)		S/N 2495186 & Later
MerCruiser R
MerCruiser MR
Alpha One	Up to 1990	S/N range 6854393-0D469858
190 IB		S/N 1564539-1720903 (Raw water pump)
225 IB		S/N 1539620-2278646 (Raw water pump)

Technical Specs

Product Type: Water Pump Impeller Kit
Installation: Direct OEM replacement
Connection: Direct drive shaft mount
Housing Material: Neoprene rubber with brass hub insert
Dimensions: Impeller diameter: 60.0 mm (2.36 in)
Impeller height: 33.8 mm (1.33 in)
Hub shaft diameter: 22.2 mm (0.87 in)
Weight: 99.3 g (3.5 oz)
Other Technical Attributes: 6 blade impeller design

What’s in the Box

1 x Water Pump Impeller (Replaces 47-89984T3)
1 x Impeller Key (28-56654)
2 x Gaskets

Installation Notes

Disconnect the battery and ensure the engine ignition is off.
Remove the lower unit (gearcase) from the outboard or sterndrive. You may need to disconnect the shift linkage.
Unbolt and remove the water pump housing cover to expose the old impeller.
Remove the old impeller, key, and any worn gaskets or seals from the housing and base plate.
Clean the inside of the pump housing and base plate, inspecting for scoring or damage. Replace the housing if significant wear is found.
Install the new gaskets, followed by the new impeller key on the driveshaft.
Slide the new impeller onto the driveshaft, aligning the keyway. Rotate the driveshaft clockwise while pushing down to seat the impeller blades correctly inside the housing.
Reinstall the water pump housing and torque its bolts to the manufacturer's specification.
Reattach the lower unit to the engine, reconnecting the shift linkage and any other components.
Once fully assembled, start the engine in water and verify that a steady stream of water is exiting the tell-tale outlet.

Troubleshooting & FAQ

How do I know if this impeller fits my specific engine?

The best way to confirm is by matching your engine's model, year, and serial number to the compatibility tables above. If you are unsure, visually compare your old impeller's dimensions and blade count to the specifications listed here before purchasing.

What are the signs of a failing water pump impeller?

Common signs include a weak or non-existent water stream from the "tell-tale" outlet, an engine overheating alarm, or a noticeable decrease in engine performance. A dry, cracked, or brittle impeller upon inspection is a clear indicator that it needs replacement.

How often should I replace my impeller?

As a preventative maintenance measure, most marine mechanics recommend replacing the water pump impeller every 1-2 years or every 100-200 hours of use, whichever comes first. This interval can be shorter if you frequently operate in sandy, silty, or saltwater conditions.

Can I run the engine dry after installing the new impeller?

No. Never run the engine without water, even for a few seconds. The water pump impeller is lubricated by water, and running it dry will cause immediate damage to the neoprene rubber, leading to premature failure.

Is this part different from the OEM version?

This is an aftermarket part designed to meet or exceed OEM specifications. It offers the same fit, form, and function as the original manufacturer's part but at a more competitive price point.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. All our parts are manufactured in an ISO 9002 certified facility and are batch-inspected for quality and consistency.

What are your shipping speed & cost?

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free for most orders, with expedited options available at checkout where applicable.

What is your warranty & returns policy?

This product is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard return window for unused items in their original condition. See our policy page or reach out for instructions.

Safety & Important Info

Verify images and specifications against 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 optimal 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 — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
Manufacturer-Direct Value — Our parts provide fair pricing without compromising on materials or quality control.

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