Water Pump Impeller – Fits Tohatsu/Mercury/Evinrude 2-6 HP (Replaces 369-65021-1, 3C8-65021-2)
Water Pump Impeller – Fits Tohatsu/Mercury/Evinrude 2-6 HP (Replaces 369-65021-1, 3C8-65021-2) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
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Water Pump Impeller – Fits Tohatsu/Mercury/Evinrude 2-6 HP (Replace...
Water Pump Impeller – Fits Tohatsu/Mercury/Evinrude 2-6 HP (Replaces 369-65021-1, 3C8-65021-2) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Water Pump Impeller – Fits Tohatsu/Mercury/Evinrude 2.5–6 HP is engineered to restore cooling performance in a wide range of small outboard motors. It is a direct-fit replacement for Tohatsu 2–6 HP 2-Stroke & 2.5–6 HP 4-Stroke (1997–2014), Mercury 2.5–6 HP 4-Stroke & 3.3–5 HP 2-Stroke (1999–2014), and various Evinrude/Nissan 2-Stroke and 4-Stroke models from 1999 to 2014.
It provides a direct interchange for OEM part numbers including Tohatsu 369-65021-1, 3C8-65021-2, Mercury 47-16154-3, Evinrude 5040180, and aftermarket equivalents like Sierra 18-3098.
- Installs as a direct replacement with no modifications needed.
- Made from durable, chlorine-resistant neoprene for reliable service.
- Features a 6-blade design to ensure consistent coolant flow.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Superseded By | Notes |
|---|---|---|---|
| Tohatsu | 369-65021-1 | For 2–6 HP models | |
| Tohatsu | 3C8650210M | 3C8-65021-2 | Physically identical to 369-65021-1 |
| Tohatsu | 3C8650211M | 3C8-65021-2 | Physically identical to 369-65021-1 |
| Tohatsu | 3C8-65021-2 | For 40-60 HP models, physically identical | |
| Mercury | 47-16154-3 | 8M0204676 | |
| Mercury | 8M0204676 | Current OEM part number | |
| Evinrude | 5040180 / 05040180 | ||
| Sierra | 18-3098 | Aftermarket Cross-Reference | |
| Sierra | 18-8922 | Aftermarket Cross-Reference | |
| CEF | 500377 | Aftermarket Cross-Reference | |
| PAT | T5-03000300 | Aftermarket Cross-Reference |
Engine & Model Compatibility
Confirm your engine model and year in the tables below. Note that the same impeller fits different HP ranges across brands.
For Tohatsu Owners: This impeller replaces both 369-65021-1 (on 2–6 HP models) and 3C8-65021-2 (on 30–60 HP models). The parts are physically identical.
For Mercury Owners: Fits a range of 2.5 HP to 6 HP four-stroke engines and 3.3 to 5 HP two-stroke engines. Please verify serial number ranges where noted.
For Evinrude/Nissan Owners: Widely used across 2 HP to 6 HP models in both 2-stroke and 4-stroke configurations.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Tohatsu | M40D, M40D2, M50D, M50D2 | 40–50 | 2-Stroke | 2006+ | 3C8-65021-2 | |
| Tohatsu | TLDI MD30B2, MD40A/B/B2, MD50A/B2 | 30–50 | 2-Stroke TLDI | 2006–2018 | 3C8-65021-2 | |
| Tohatsu | M40C | 40 | 2-Stroke | 2013 | 3C8-65021-2 | Model 1301 |
| Tohatsu | MFS40A, MFS50A, MFS60 | 40–60 | 4-Stroke | 2014+ | 3C8-65021-2 | |
| Tohatsu | M2, M2.5, M3.5A, M3.5B | 2–3.5 | 2-Stroke | 1999–2019 | 369-65021-1 | Earlier models |
| Tohatsu | M4, M5, M6 | 4–6 | 2-Stroke | 1997–2014 | 369-65021-1 | Earlier models |
| Tohatsu | MFS2.5, MFS3.5 | 2.5–3.5 | 4-Stroke | 2006+ | 369-65021-1 | |
| Tohatsu | MFS4, MFS5, MFS6 | 4–6 | 4-Stroke | 1999–2014 | 369-65021-1 | |
| Mercury | 2-2.5-3.5 | 4-Stroke (Carb) | 2006+ | 47-16154-3/8M0204676 | Serial from 0R131842+ | |
| Mercury | 4–5–6 | 4-Stroke | 1999+ | 47-16154-3/8M0204676 | Serial from 0P073456+ | |
| Mercury | 3.3–5 | 2-Stroke | 1999–2014 | 47-16154-3 | ||
| Nissan/Evinrude | NS2, NS2.5, NS3.5 | 2–3.5 | 2-Stroke | 1999–2019 | 369-65021-1 | |
| Nissan/Evinrude | NS4, NS5, NS6 | 4–6 | 2-Stroke | 1997–2014 | 369-65021-1 | |
| Nissan/Evinrude | NSF2.5, NSF3.5 | 2.5–3.5 | 4-Stroke | 2006+ | 369-65021-1 | |
| Nissan/Evinrude | NSF4, NSF5, NSF6 | 4–6 | 4-Stroke | 1999–2014 | 369-65021-1 | |
| Evinrude | 3–5 | 2-Stroke | 1999–2014 | 5040180/05040180 |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct replacement
- Material
- Neoprene
- Dimensions
- A: 10.35 mm (shaft insert diameter)
B: 33.60 mm (overall diameter)
C: 14.35 mm (height) - Blades
- 6
- Warranty
- 1 Year (aftermarket); OEM warranty where applicable
- Certification
- Manufactured in ISO9002 certified facility (aftermarket)
What’s in the Box
- 1 x Water Pump Impeller (replaces 369-65021-1 or 3C8-65021-2)
Installation Notes
- Disconnect the battery and remove the lower unit (gearcase) from the engine.
- Unbolt the water pump housing to access the impeller. Note the blade direction of the old impeller before removal.
- Remove the old impeller, woodruff key, and any gaskets.
- Thoroughly clean all surfaces of the pump housing and wear plate, removing any debris or salt buildup.
- Install new gaskets and place the woodruff key on the driveshaft.
- Slide the new impeller onto the shaft. While pushing the housing down, turn the driveshaft clockwise to correctly bend the blades into place.
- Bolt the housing back on, tightening bolts to the manufacturer's recommended torque.
- Reinstall the lower unit, reconnect the battery, and test the engine in water to verify a strong, steady water flow from the tell-tale outlet.
Troubleshooting & FAQ
How do I confirm this impeller fits my outboard?
The most reliable method is to match your existing part number to one listed in our "Part Number Matrix." You can also check your engine's model, horsepower, and year against the "Engine & Model Compatibility" table. Always visually compare the photos to your old part before ordering.
What is the difference between part numbers 369-65021-1 and 3C8-65021-2?
While these two part numbers apply to different Tohatsu engine horsepower ranges, the impellers themselves are physically identical in dimensions and material. This part is a direct replacement for both OEM numbers.
How often should an impeller be replaced?
As a general rule, we recommend inspecting your impeller annually and replacing it every 1–2 years or every 100–200 hours of use, whichever comes first. Replacement may be needed more frequently if you operate in sandy, silty, or saltwater environments.
What are the signs of a failing water pump impeller?
The most common symptom is the engine overheating, especially at idle or low speeds. Other indicators include a weak or non-existent water stream from the "tell-tale" outlet, or discovering the old impeller's blades are cracked, brittle, or broken during an inspection.
Is this an OEM or aftermarket part?
This listing is for an aftermarket replacement part, not an OEM component. It is built to meet or exceed OEM-level specifications using comparable materials and is manufactured in an ISO 9002 certified facility with batch inspections for quality and consistency.
What are the shipping speed and cost?
We ship worldwide quickly, with typical transit times of 5–15 days for most regions. Standard shipping is free, and expedited options may be available at checkout depending on your location.
What is the warranty and return policy?
This part 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 window for items that are unused and in 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 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, typically arriving in 5–15 days.
- Manufacturer-Direct Value — Fair pricing on quality components without compromising on materials or quality control.
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