Water Pump Impeller – Fits Tohatsu & Nissan 9.9HP-20HP (Replaces 334-65021-0)

Water Pump Impeller – Fits Tohatsu & Nissan 9.9HP-20HP (Replaces 334-65021-0)

This water pump impeller is designed for a wide range of Tohatsu and Nissan outboard motors. It fits Tohatsu 2-stroke (M9.9, M12, M15, M18) and 4-stroke (MFS9.9, MFS15, MFS18, MFS20) models, as well as Nissan 2-stroke (NS9.9, NS15, NS18) and 4-stroke (NSF9.9, NSF15, NSF18, NSF20) models.

It serves as a direct replacement for multiple OEM part numbers, including Tohatsu/Nissan 334-65021-0, Mercury 47-803748, Honda 19210-935-003, and Evinrude 5040046.

• Installation Method: Direct Replacement
• Fuel Compatibility: Gasoline
• Package Contents: Includes one water pump impeller

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

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.

For Johnson/Evinrude owners, here’s a guide to help you identify your engine’s serial/model: Johnson Serial Number Guide.

Technical Specifications

Package Contents

• 1 x Water Pump Impeller (334-65021-0)

Installation Guide

1. Safety First: Disconnect the engine's battery and remove the safety lanyard from the kill switch.
2. Access the Lower Unit: Place the outboard in a secure position. Locate and unbolt the lower unit (gearcase) from the upper engine leg.
3. Remove Lower Unit: Carefully separate the lower unit from the driveshaft housing. You may need to disconnect a speedometer tube or shift linkage.
4. Open Water Pump Housing: Locate the water pump assembly on top of the lower unit. Unscrew the bolts to remove the pump cover.
5. Remove Old Impeller: Note the rotational direction of the old impeller's blades before sliding it off the driveshaft.
6. Inspect and Clean: Clean the inside of the pump housing and the wear plate. Inspect them for grooves, warping, or damage and replace if necessary.
7. Install New Impeller: Lightly lubricate the new impeller and the inside of the housing. Slide the new impeller onto the driveshaft while turning the shaft clockwise to correctly bend the blades.
8. Reassemble: Reinstall the water pump housing and torque the bolts to the manufacturer's specification.
9. Reattach Lower Unit: Guide the lower unit back into place, ensuring the driveshaft, water tube, and shift shaft align correctly. Bolt it securely.
10. Test Operation: Reconnect the battery. Start the engine in a water test tank or with a hose attachment to confirm a strong and steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

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.

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• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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