Water Pump Impeller – Fits Johnson/Evinrude 9.5HP & 10HP (Replaces 377178, 775519)

Water Pump Impeller – Fits Johnson/Evinrude 9.5HP & 10HP (Replaces 377178, 775519)

This aftermarket water pump impeller is a direct replacement for Johnson/Evinrude 9.5HP 2-Stroke outboards from 1964–1973 and 10HP 2-Stroke models from 1958–1963. It is engineered to meet or exceed OEM specifications for reliable cooling performance.

It serves as a direct replacement for several aftermarket part numbers, including Sierra 18-3003, Mallory 9-45218, GLM 89670, SEI Marine 96-361-03BE, and CEF 500349.

• Engineered for direct, hassle-free installation.
• Constructed from durable rubber with a corrosion-resistant copper/brass insert.
• Restores proper water circulation to prevent engine overheating.

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

Technical Specifications

Package Contents

1 x Water Pump Impeller (Replaces 377178/775519)

Installation Guide

1. Ensure the engine is off and the battery is disconnected.
2. Remove the lower unit (gearcase) from the outboard's driveshaft housing.
3. Locate the water pump housing on top of the lower unit and remove the bolts securing it.
4. Slide the housing up and off the driveshaft to expose the impeller.
5. Remove the old impeller, taking note of the blade orientation. Clean any debris from the housing interior.
6. Slide the new impeller onto the driveshaft, aligning it with the key slot.
7. Gently turn the driveshaft clockwise while pushing down on the impeller to seat the blades correctly inside the housing.
8. Re-install the water pump housing and torque the bolts to the manufacturer's specification.
9. Re-attach the lower unit to the engine.
10. Once assembled, start the engine and verify a steady stream of water from the cooling system's tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this impeller fits my engine?

A: The best way is to match your engine's model and year to the "Compatible Engine Models" list. You can also confirm by comparing your old part number to those in the "Part Number Cross-Reference" table.

Q: What are the signs of a failing water pump impeller?

A: Common symptoms include the engine overheating, a weak or intermittent water stream from the tell-tale (water discharge) outlet, or finding cracked, stiff, or broken blades during a visual inspection.

Q: How often should I replace the water pump impeller?

A: As a crucial part of preventative maintenance, it's recommended to replace the impeller every 1-2 years or every 100-200 hours of operation, especially if used frequently in saltwater or debris-heavy water.

Q: OEM vs. 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?

• 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.