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

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

This high-quality water pump impeller fits Johnson/Evinrude 9.5 HP (1964-1973) and 10 HP (1958-1963) 2-Stroke outboard engines, ensuring proper cooling system function.

It is a direct replacement for multiple OEM and aftermarket part numbers, including Johnson/Evinrude 377178, 775519, 777833, Sierra 18-3003, GLM 89670, Mallory 9-45218, and others.

• Installation: Direct replacement for a straightforward installation.
• Material: Constructed from durable neoprene rubber for reliable performance.
• Package Includes: 1 x 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 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. Disconnect the battery and ensure the engine is off and cool.
2. Place the outboard motor in a secure position, either on a stand or tilted up.
3. Locate and remove the lower unit (gearcase) by unbolting it from the engine's midsection.
4. Once the lower unit is removed, unbolt and detach the water pump housing.
5. Carefully note the rotational direction of the old impeller's blades before sliding it off the driveshaft.
6. Thoroughly clean the inside of the pump housing and inspect it for any grooves, cracks, or warping.
7. Lightly lubricate the new impeller and the inside of the housing with marine grease.
8. Slide the new impeller onto the driveshaft while turning the shaft clockwise to bed the blades correctly.
9. Reinstall the water pump housing, ensuring any gaskets or seals are properly aligned. Torque bolts to manufacturer specifications.
10. Reattach the lower unit to the engine, making sure the driveshaft and water tube align correctly.
11. Securely fasten all bolts and reconnect the battery.
12. Start the engine using a water supply (flushing muffs or in water) to verify strong, steady water flow from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this impeller fits my engine?
Verify your engine's model and year against the "Compatible Engine Models" list. This impeller fits Johnson/Evinrude 9.5 HP (1964-1973) and 10 HP (1958-1963) models. You can also match your existing part number with our "Part Number Cross-Reference" table.

What are the signs of a failing water pump impeller?
A weak or non-existent water stream from the engine's "tell-tale" port is the most common sign. Other indicators include engine overheating alarms, steam from the exhaust, and reduced engine power.

How often should I replace the water pump impeller?
It is recommended to inspect the impeller annually and replace it every 1-2 years as part of routine maintenance. If you frequently operate in saltwater or debris-heavy water, consider yearly replacement to prevent engine damage.

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

• 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.