Water Pump Impeller for Yamaha 2HP Outboard – 646-44352
This water pump impeller is engineered for Yamaha 2-stroke 2HP outboard motors produced from 1986 to 2002. Designed to maintain optimal cooling performance, it ensures reliable water circulation through your engine's cooling system.
This impeller directly replaces OEM part numbers 646-44352, 646-44352-01, and 646-44352-01-00, as well as aftermarket equivalents from CEF Marine, Sierra Marine, Mallory Marine, and GLM Marine.
- Features 6 durable rubber blades for efficient water flow
- Pre-measured dimensions ensure drop-in fitment
- Essential maintenance component for cooling system health
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Yamaha Marine |
646-44352, 646-44352-01, 646-44352-01-00, 646443520100, 6464435201 |
| CEF Marine |
500324 |
| Sierra Marine |
18-3072 |
| Mallory Marine |
9-45604 |
| GLM Marine |
89850 |
Compatible Engine Models
Confirm your engine model/year in the table below. For Yamaha owners, here's a guide to help you identify your engine's serial/model: Yamaha Serial Number Guide. You can also review exploded diagrams to verify part numbers: Yamaha Parts Diagrams & Catalog.
| Brand |
Model |
Rated HP |
Stroke |
Years |
| Yamaha |
2SJ |
2HP |
2-Stroke |
1986 |
| Yamaha |
2SH |
2HP |
2-Stroke |
1987 |
| Yamaha |
2SG |
2HP |
2-Stroke |
1988 |
| Yamaha |
2SF |
2HP |
2-Stroke |
1989 |
| Yamaha |
2SD |
2HP |
2-Stroke |
1990 |
| Yamaha |
2MSHP |
2HP |
2-Stroke |
1991 |
| Yamaha |
2MSHQ |
2HP |
2-Stroke |
1992 |
| Yamaha |
2MSHR |
2HP |
2-Stroke |
1993 |
| Yamaha |
2MSHS |
2HP |
2-Stroke |
1994 |
| Yamaha |
2MSHT |
2HP |
2-Stroke |
1995 |
| Yamaha |
2MSHU |
2HP |
2-Stroke |
1996 |
| Yamaha |
2MSHV |
2HP |
2-Stroke |
1997 |
| Yamaha |
2MSHW |
2HP |
2-Stroke |
1998 |
| Yamaha |
2MSHX |
2HP |
2-Stroke |
1999 |
| Yamaha |
2MSHY |
2HP |
2-Stroke |
2000 |
| Yamaha |
2MSHZ, 2MSHKZ |
2HP |
2-Stroke |
2001 |
| Yamaha |
2MSHA |
2HP |
2-Stroke |
2002 |
Technical Specifications
| Specification |
Value |
| Number of Blades |
6 |
| Impeller Height |
14.0 mm / 0.55 inch |
| Overall Diameter |
47.90 mm / 1.89 inch |
| Hub Shaft Diameter |
10.90 mm / 0.43 inch |
| Net Weight |
0.35 oz |
Package Contents
Your order includes:
- Water Pump Impeller (1 piece)
Installation Guide
- Disconnect the fuel line and remove the lower unit from the outboard motor following your service manual.
- Remove the water pump housing cover and extract the old impeller, noting its orientation.
- Clean the impeller housing thoroughly, removing all debris, old gasket material, and corrosion.
- Inspect the housing for wear or damage; replace if grooves or cracks are present.
- Apply marine-grade grease to the new impeller blades and housing interior for lubrication during initial startup.
- Install the new impeller with blades oriented in the correct rotation direction (typically clockwise when viewed from above).
- Replace the faceplate gasket and any o-rings with new components to prevent leaks.
- Reassemble the water pump housing and secure all fasteners to manufacturer torque specifications.
- Reinstall the lower unit onto the motor, ensuring proper alignment and engagement.
- Reconnect the fuel line and run the engine in a test tank or on-water to verify water flow from the telltale outlet.
- Check for leaks around the pump housing and lower unit seals during the test run.
- Monitor engine temperature during initial operation to confirm proper cooling system function.
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my Yamaha 2HP outboard?
A: Check the compatible models table above for your engine's year and model number. You can also cross-reference the OEM part number on your original impeller (646-44352 or 646-44352-01) to confirm fitment.
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 reduced water flow from the telltale, overheating, or visible blade damage, replace it immediately regardless of service interval.
Q: What are the signs that my impeller is failing?
A: Common symptoms include weak or no water discharge from the telltale outlet, engine overheating, steam from the powerhead, reduced water pressure, or visible cracks and missing pieces on the impeller blades during inspection.
Q: Can I reuse the old gaskets and seals when installing this impeller?
A: No, always replace gaskets, o-rings, and seals during impeller service. Reusing old seals can cause leaks and compromise cooling system performance, leading to engine damage.
Q: Do I need to lubricate the impeller before installation?
A: Yes, apply marine-grade waterproof grease to the impeller blades and housing. This prevents dry-start damage and helps the impeller seat properly during initial engine startup.
Q: What's the difference between OEM and aftermarket impellers?
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?
-
Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
-
Fast Global Shipping: Free delivery worldwide in 5–15 days.
-
Direct from Manufacturer: Competitive pricing without compromising quality.