Water Pump Impeller Repair Kit – Fits Tohatsu/Nissan 4-6 HP Outboards
This water pump impeller repair kit is designed for Tohatsu and Nissan 4 HP, 5 HP, and 6 HP 4-Stroke outboard motors. It provides a reliable solution for maintaining your engine's cooling system, fitting MFS4/5/6 and NSF4/5/6 series engines among others.
This kit serves as a direct replacement for Tohatsu part numbers 369-87322-0, 369873220M, 369873222M; Nissan part numbers 369-87322-1, 369873221M; and Mercury part number 16159A03.
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Complete Kit: Includes essential components for a full replacement: impeller, gaskets, and guide plates.
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Durable Materials: Constructed from a robust combination of plastic and metal for longevity.
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Direct Fit: Engineered for direct installation without modification.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
Superseded By |
| Tohatsu |
369-87322-0 |
369873222M |
| Tohatsu |
369873220M |
369873222M |
| Nissan |
369-87322-1 |
|
| Nissan |
369873221M |
|
| Mercury |
16159A03 |
|
Compatible Engine Models
Confirm your engine model/year in the table below.
| Brand |
Model |
Rated HP |
Stroke |
Years |
OEM Part No. |
| Tohatsu |
M4C |
4 |
4-Stroke |
|
369-87322-0 |
| Tohatsu |
MFS4B |
4 |
4-Stroke |
2002-2014 |
369-87322-0 |
| Tohatsu |
MFS4C |
4 |
4-Stroke |
2011-2014 |
369-87322-0 |
| Tohatsu |
M5B |
5 |
4-Stroke |
2003 |
369-87322-0 |
| Tohatsu |
MFS5B |
5 |
4-Stroke |
2002-2010 |
369-87322-0 |
| Tohatsu |
MFS5C |
5 |
4-Stroke |
2011-2014 |
369-87322-0 |
| Tohatsu |
MFS6B |
6 |
4-Stroke |
2002-2010 |
369-87322-0 |
| Tohatsu |
MFS6C |
6 |
4-Stroke |
2011-2014 |
369-87322-0 |
| Nissan |
NS4C |
4 |
4-Stroke |
|
369-87322-1 |
| Nissan |
NSF4B |
4 |
4-Stroke |
2002-2010 |
369-87322-1 |
| Nissan |
NSF4C |
4 |
4-Stroke |
2011-2014 |
369-87322-1 |
| Nissan |
NS5B |
5 |
4-Stroke |
2003 |
369-87322-1 |
| Nissan |
NSF5A2 |
5 |
4-Stroke |
2002 |
369-87322-1 |
| Nissan |
NSF5B |
5 |
4-Stroke |
2002-2010 |
369-87322-1 |
| Nissan |
NSF5C |
5 |
4-Stroke |
2011-2014 |
369-87322-1 |
| Nissan |
NSF6B |
6 |
4-Stroke |
2002-2010 |
369-87322-1 |
| Nissan |
NSF6C |
6 |
4-Stroke |
2011-2014 |
369-87322-1 |
Technical Specifications
| Specification |
Value |
| Product Type |
Water Pump Impeller Repair Kit |
| Installation |
Direct replacement |
| Housing Material |
Plastic + metal |
| Components |
Impeller, gaskets, guide plates |
| Dimensions |
As shown in manufacturer images [verify orientation] |
| Weight |
7.1 ounces (201g) |
| Warranty |
Varies by seller (1 year for FridayParts) |
Package Contents
1 x Water Pump Impeller Repair Kit, replacing OEM parts 369-87322-0/369873220M and 369-87322-1/369873221M.
Installation Guide
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Safety First: Disconnect the battery and remove the engine cover before starting work.
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Drain Gear Lube: Place a drain pan under the lower unit and remove the drain/fill screws to empty the gear lube.
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Remove Lower Unit: Unbolt the lower unit (gearcase) from the engine's midsection and carefully lower it.
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Access Impeller: Remove the bolts securing the water pump housing. Lift the housing to expose the old impeller. Note the rotational direction of the old impeller's blades.
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Remove Old Components: Take out the old impeller, woodruff key, wear plates, and gaskets.
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Clean Surfaces: Thoroughly clean the mounting surfaces of the housing and base plate, removing any old gasket material or corrosion.
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Install New Components: Place the new gaskets and wear plates on the housing and base. Install the new woodruff key in the driveshaft slot.
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Install New Impeller: Slide the new impeller down onto the driveshaft. Turn the driveshaft clockwise while pushing down to ensure the impeller blades are oriented correctly.
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Reassemble Pump: Apply a light coat of marine grease to the inside of the housing and reinstall it. Tighten bolts to the manufacturer's specified torque.
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Reinstall Lower Unit: Guide the lower unit back into place, ensuring the driveshaft and water tube align. Securely tighten the mounting bolts.
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Refill Gear Lube: Fill the lower unit with fresh gear lube from the bottom fill hole until it seeps out the top one, then replace both screws.
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Test Operation: Reconnect the battery, start the engine in water, and verify a steady stream of water is exiting the tell-tale outlet.
Troubleshooting & FAQ
How do I confirm this fits my engine?
This kit is designed for Tohatsu/Nissan 4, 5, and 6 HP 4-stroke outboards (e.g., MFS/NSF series). The most reliable method to ensure fitment is to match your engine's original part number to our cross-reference list (e.g., 369-87322-0, 369-87322-1, etc.). You should also consult the compatible engine model table to verify your specific model and year.
What are the signs of a failing water pump impeller?
Common signs of a worn or damaged impeller include a weak or intermittent water stream from the "tell-tale" exhaust port, engine overheating alarms, or reduced engine performance. Failure to replace it can lead to severe engine damage.
How often should I replace the water pump impeller?
As a general rule for preventative maintenance, you should inspect the impeller annually and replace it every 1-2 years or 100-200 hours of use. Replacement intervals may be shorter if you frequently operate in sandy, silty, or saltwater environments.
OEM vs. Aftermarket?
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.
How fast do you ship and how much does it cost?
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.
What is your warranty and return policy?
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
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Verify Fitment: 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.
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Aftermarket Part: This product is an aftermarket replacement part and is not an OEM component.
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Installation: 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.