Water Pump Impeller – Fits Tohatsu & Nissan 25HP-40HP Outboard Motors (Replaces 345-65021-0)
Water Pump Impeller – Fits Tohatsu & Nissan 25HP-40HP Outboard Motors (Replaces 345-65021-0) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Impeller – Fits Tohatsu & Nissan 25HP-40HP Outboard ...
Product Details
This aftermarket Water Pump Impeller – Fits Tohatsu & Nissan 25HP-40HP Outboard Motors (Replaces 345-65021-0) is designed for a range of 2-stroke and 4-stroke outboard engines. It provides a reliable cooling solution for Tohatsu M25-M40 and MFS series, Nissan NS25-NS40 and NSF series, and select Mercury/Mariner 25/30HP models.
It serves as a direct replacement for Tohatsu part 345-65021-0 (and its variants 345650210M, 3R0650210M), Nissan 345-65021-0, Mercury 47-16154-1, and Sierra 18-8923.
- Installs as a direct OEM-equivalent replacement.
- Made from durable, high-quality neoprene for reliable performance.
- Includes one water pump impeller for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Tohatsu | 345-65021-0 |
| Tohatsu | 345650210M |
| Tohatsu | 3R0650210M |
| Nissan | 345-65021-0 |
| Nissan | 345650210M |
| Mercury | 47-16154-1 |
| Sierra | 18-8923 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Fits various 2-stroke and 4-stroke Tohatsu outboards from 25HP to 40HP.
Cross-references to Nissan outboards in the same power range.
Also compatible with certain Mercury/Mariner models that use part number 47-16154-1.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Tohatsu | M25C2/C3 | 25 | 2-Stroke | 345-65021-0 | ||
| Tohatsu | M30A3/A4 | 30 | 2-Stroke | 345-65021-0 | ||
| Tohatsu | M35C | 35 | 2-Stroke | 345-65021-0 | Some listings include 35HP | |
| Tohatsu | M40C | 40 | 2-Stroke | 345-65021-0 | Some listings include 40HP | |
| Tohatsu | MFS25B | 25 | 4-Stroke | 2005–2014 | 345-65021-0 | |
| Tohatsu | MFS30B | 30 | 4-Stroke | 2005–2014 | 345-65021-0 | |
| Nissan | NS25C2/C3 | 25 | 2-Stroke | 345-65021-0 | ||
| Nissan | NS30A3/A4 | 30 | 2-Stroke | 345-65021-0 | ||
| Nissan | NS35C | 35 | 2-Stroke | 345-65021-0 | Some listings include 35HP | |
| Nissan | NS40C | 40 | 2-Stroke | 345-65021-0 | Some listings include 40HP | |
| Nissan | NSF25B | 25 | 4-Stroke | 2005–2014 | 345-65021-0 | |
| Nissan | NSF30B | 30 | 4-Stroke | 2005–2014 | 345-65021-0 | |
| Mercury/Mariner | 25-30 | 47-16154-1 | Cross-referenced part number |
Technical Specs
- Product Type
- Water Pump Impeller
- Installation
- Direct OEM replacement
- Material
- Neoprene
- Number of Blades
- 6
- Inner Diameter
- 17 mm
- Outer Diameter
- 44 mm
- Height/Width
- 20 mm
- Hub Type
- Plastic
- Weight
- 11 g (0.39 oz)
- Color
- Black
- Warranty
- Varies by seller (1 year typical for aftermarket)
What’s in the Box
- 1 x Water Pump Impeller (345-65021-0)
Installation Notes
- Disconnect the battery and shift the outboard into neutral.
- Locate and remove the lower unit (gearcase) bolts and carefully separate the unit.
- Unbolt and remove the water pump housing cover.
- Slide the old impeller off the drive shaft, noting the direction of the blades.
- Clean the housing and inspect components for wear. Apply a light coat of marine grease to the interior.
- Install the new impeller by sliding it onto the driveshaft while turning the shaft clockwise to bed the blades correctly.
- Reinstall the water pump housing, ensuring a proper seal.
- Re-attach the lower unit and tighten all bolts to the manufacturer's specified torque.
Troubleshooting & FAQ
How do I know if this impeller fits my engine?
The best way to ensure correct fitment is to check your engine's model and year against the compatibility table provided. For absolute certainty, verify that your existing part number matches one of the cross-references listed in the Part Number Matrix, such as Tohatsu 345-65021-0 or Mercury 47-16154-1.
What are the signs of a failing water pump impeller?
Common signs include the engine overheating at idle or low speeds, a weak or non-existent stream of water from the "tell-tale" outlet, or a brittle or cracked appearance on the old impeller during inspection.
How often should I replace my impeller?
For preventative maintenance, it is recommended to replace the impeller every 1 to 2 years, or every 100-200 hours of operation, depending on usage conditions (e.g., saltwater vs. freshwater).
My 40HP Tohatsu/Nissan engine is not listed everywhere. Will this fit?
While this impeller primarily fits 25HP and 30HP models, some sources indicate compatibility with 35HP and 40HP models like the Tohatsu M40C and Nissan NS40C. Always verify your engine's OEM part number is 345-65021-0 before purchasing to ensure it's the correct part for your specific motor.
Can I install this part myself?
Yes, replacing an impeller can be done with basic mechanical skills and tools. However, due to the importance of the cooling system, professional installation is recommended if you are not fully comfortable with the procedure.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our 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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