Water Pump Impeller – Fits Tohatsu/Nissan/Mercury 40-90HP 2-Stroke (Replaces 3B7-65021-2)
Water Pump Impeller – Fits Tohatsu/Nissan/Mercury 40-90HP 2-Stroke (Replaces 3B7-65021-2) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Water Pump Impeller – Fits Tohatsu/Nissan/Mercury 40-90HP 2-Stroke ...
Water Pump Impeller – Fits Tohatsu/Nissan/Mercury 40-90HP 2-Stroke (Replaces 3B7-65021-2) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Water Pump Impeller – Fits Tohatsu/Nissan/Mercury 40-90HP 2-Stroke (Replaces 3B7-65021-2) is a crucial component for maintaining your engine's cooling system. It is designed to fit a wide range of Tohatsu and Nissan 2-stroke outboards (60-140HP, 1992-2003), select modern Tohatsu 4-stroke models (MFS8/9.8HP, 2022+), and specific Mercury 4-stroke engines (8-9.9HP, 2005+).
This single component serves as a direct interchange for multiple part numbers, including Tohatsu 3B7-65021-2, 3C7-65021-1, 3B2-65021-1, Mercury 8M0214945, 8037481, and Sierra 18-8924, ensuring broad compatibility.
- Installation Location: Mounts inside the water pump housing on the lower unit/gearcase.
- Driveshaft Connection: Features a keyed hub for a secure fit to the driveshaft.
- Technical Design: Engineered with 6 blades for efficient water flow.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number |
|---|---|
| Tohatsu/Nissan | 3B7-65021-2 |
| Tohatsu/Nissan | 3B7650210 / 3B7650210M |
| Tohatsu/Nissan | 3B7650211 / 3B7650211M |
| Tohatsu/Nissan | 3B7650212 / 3B7650212M |
| Tohatsu/Nissan | 3C7-65021-1 |
| Tohatsu/Nissan | 3C7650210 / 3C7650210M |
| Tohatsu/Nissan | 3C7650211 / 3C7650211M |
| Tohatsu/Nissan | 3B2-65021-1 |
| Mercury | 8M0214945 |
| Mercury | 8037481 / 47-8037481 |
| Sierra | 18-8924 |
Engine & Model Compatibility
Confirm your engine model and year in the tables below. Proper verification is essential.
For Tohatsu/Nissan Owners: This impeller fits various 2-stroke models from 60HP to 140HP and select modern MFS 8/9.8HP 4-stroke outboards.
For Mercury Owners: Compatible with specific 8-9.9HP (209cc) 4-stroke models manufactured from 2005 onwards (serial number 0P325500 and up).
For Parsun Owners: Cross-referenced to fit certain F6 and F8 models. Please measure your existing impeller to confirm dimensional compatibility before ordering.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Tohatsu | M60C, M70C | 60-70HP | 2-Stroke | 1992–2003 | 3B7-65021-2 | |
| Tohatsu | M90A | 90HP | 2-Stroke | 1992–2003 | 3B7-65021-2 | |
| Tohatsu | M115, M120, M140 | 115-140HP | 2-Stroke | 1994–2003 | 3C7-65021-1 | Alternate part number |
| Tohatsu | MFS8, MFS9.8 | 8-9.8HP | 4-Stroke | 2022+ | 3B2-65021-1 | |
| Mercury | 8HP, 9.9HP (209cc) | 8-9.9HP | 4-Stroke | 2005+ (0P325500+) | 8M0214945, 8037481 | |
| Parsun | F6, F8 | 6-8HP | Compatible per JLM Marine |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Lower Unit/Gearcase
- Connection
- Key/Spline Fit to Driveshaft
- Dimensions
- ID: 20.15 mm, OD: 67.40 mm, Width: 35.10 mm (Tohatsu specs)
- Blades
- 6
- Fitting Type
- Keyed Shaft/Spline
- Warranty
- 1 Year
What’s in the Box
- 1 x Water Pump Impeller
Installation Notes
- Disconnect the battery and shift linkage before beginning work.
- Remove the lower unit (gearcase) mounting bolts and carefully drop the unit.
- Unbolt and remove the water pump housing to access the old impeller.
- Note the rotational direction of the old impeller's blades for correct installation of the new one.
- Remove the old impeller, woodruff key, and any gaskets.
- Thoroughly clean the pump housing and wear plate interior surfaces.
- Install the new key and lightly lubricate the impeller and housing with marine grease.
- Install the new impeller, turning the driveshaft clockwise to correctly seat the blades.
- Reassemble the pump housing with new gaskets and torque bolts to manufacturer specifications.
- Reinstall the lower unit, ensuring the water tube, driveshaft, and shift shaft are properly aligned.
- Reconnect shift linkage and battery terminals.
- Start the engine using a water supply (flushing muffs) and verify a strong water stream from the telltale outlet.
Troubleshooting & FAQ
How do I know if this impeller fits my engine?
This impeller fits a specific range of Tohatsu, Nissan, and Mercury outboards. Please consult the "Engine & Model Compatibility" and "Part Number Matrix" sections. Cross-reference your engine's model, year, and original part number to ensure a match.
What are the signs of a failing water pump impeller?
Common signs include an engine overheating alarm, a weak or non-existent stream of water from the "telltale" outlet, or finding rubber fragments in the cooling system or on the engine block.
det>How often should I replace my impeller?
As a general maintenance guideline, impellers should be inspected annually and replaced every 1-2 years or every 100-200 hours of use, whichever comes first. This interval can shorten based on operating conditions, especially in sandy or silty water.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility and batch-inspected for consistency and quality.
Shipping speed & cost?
We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most regions, with expedited options available at checkout where applicable.
Warranty & returns?
This part is covered by a 1-year warranty against manufacturing defects under normal use. If you encounter an issue, contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition.
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 part, not an original equipment manufacturer (OEM) component.
- Professional installation is highly recommended for safety, proper function, and engine longevity.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and relentlessly tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with an average transit time of 5–15 days.
- Manufacturer-Direct Value — Our model provides fair pricing without compromising on materials, quality control, or performance.
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