Water Pump Impeller – Fits Tohatsu Nissan Mercury Mariner 2.5HP 3.5HP Outboards
This aftermarket water pump impeller is designed to fit Mariner 2HP, 2.5HP, and 3HP outboard engines, as well as compatible Tohatsu 2.5A, 3.5A, and 3.5B models. It provides reliable cooling system performance for your small outboard motor, ensuring consistent water flow and engine temperature regulation.
This impeller directly replaces OEM part numbers 309-65021-2, 47-95289-2, and 47-114812 across Tohatsu, Nissan, Mercury, and Mariner brands, along with aftermarket references from CEF and Mallory.
- Includes impeller with key/pin for complete installation
- Designed for small 2–3.5HP outboard engines
- Drop-in replacement for multiple OEM references
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Tohatsu / Nissan |
309-65021-2 |
| Mercury / Mariner |
47-95289-2 |
| Mercury / Mariner |
47-114812 |
| CEF |
500396 |
| Mallory |
9-45312 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here's a guide to help you identify your engine's serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand |
Model |
Rated HP |
| Mariner |
Various |
2HP |
| Mariner |
Various |
2.5HP |
| Mariner |
Various |
3HP |
| Tohatsu |
2.5A |
2.5HP |
| Tohatsu |
3.5A |
3.5HP |
| Tohatsu |
3.5B |
3.5HP |
Technical Specifications
| Specification |
Value |
| Part Type |
Water Pump Impeller |
| Material |
Rubber |
| Includes |
Impeller with Key / Pin |
Package Contents
- One (1) Outboard Rubber Impeller with Key / Pin
Installation Guide
- Disconnect the fuel line and remove the lower unit from the outboard motor following your engine's service manual.
- Remove the water pump housing cover and carefully extract the old impeller. Note the direction of the impeller blades for proper orientation.
- Clean the pump housing and inspect for wear, corrosion, or debris that could damage the new impeller.
- Lubricate the new impeller with water pump grease or glycerin to ease installation and prevent dry starts.
- Insert the key/pin into the impeller hub, aligning it with the drive shaft slot.
- Carefully slide the impeller onto the drive shaft, ensuring blades are oriented in the correct rotation direction.
- Reinstall the pump housing cover, ensuring all gaskets and O-rings are properly seated.
- Reassemble the lower unit to the outboard, torquing all fasteners to manufacturer specifications.
- Reconnect the fuel line and run the engine in a test tank or on muffs to verify proper water flow from the tell-tale.
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my engine?
A: Cross-reference your current impeller's OEM part number with the numbers listed above (309-65021-2, 47-95289-2, 47-114812). Additionally, confirm your engine model matches Mariner 2HP/2.5HP/3HP or Tohatsu 2.5A/3.5A/3.5B.
Q: How often should I replace my water pump impeller?
A: Most manufacturers recommend replacing the impeller every 2–3 years or 200–300 hours of operation, whichever comes first. If you notice overheating, reduced water flow from the tell-tale, or visible wear/cracks, replace it immediately.
Q: What are the signs of a failing impeller?
A: Common symptoms include weak or no water flow from the tell-tale indicator, engine overheating, steam from the engine, or loss of power. Inspect the impeller if you experience any of these issues.
Q: Does this impeller come with the key or pin?
A: Yes, this package includes the impeller with the key/pin required for installation on the drive shaft.
Q: Can I install this myself or do I need a mechanic?
A: If you have basic mechanical skills and follow your engine's service manual, you can install it yourself. However, professional installation is recommended to ensure proper orientation and avoid damage.
Q: Is this an OEM part or aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.