Water Pump Impeller for Evinrude/Johnson 9.5 HP & 10 HP Outboards – Replaces 377178, 775519

Product Details

This aftermarket water pump impeller is designed for selected Evinrude/Johnson 2-stroke outboard applications, including 9.5 HP models from 1964–1973 and 10 HP models from 1958–1963. It is intended to replace the original impeller in the applicable water pump housing and help restore proper cooling-water circulation.

The impeller is listed for the Evinrude/Johnson, OMC, and BRP reference numbers 377178, 775519, and 777833. Additional aftermarket cross-references listed for this application include Sierra 18-3003, Mallory 9-45218, GLM 89670, SEI Marine 96-361-03BE, and CEF 500349. Always verify the complete engine model and year before ordering.

• Replacement water pump impeller for specified Evinrude/Johnson outboards.
• Designed for installation in the original water pump housing.
• Suitable for the listed 9.5 HP and 10 HP 2-stroke applications.
• Single impeller supplied; this is not a multi-piece water pump service kit.

Part Number Matrix

Use the following numbers as application cross-references. Cross-reference numbers do not replace confirmation of the engine model, year, and existing impeller dimensions.

Engine & Model Compatibility

The following Evinrude/Johnson model and year combinations are listed for this impeller. Confirm the model designation, horsepower, stroke, and year on your outboard before installation.

Technical Specifications

Product Type

Water pump impeller

Application

Evinrude/Johnson 9.5 HP and 10 HP 2-stroke outboards listed above

Installation

Replacement for the original impeller in the applicable water pump housing

Outside Diameter

2.50 in (approximately 63.5 mm)

Inside Diameter

0.550 in (approximately 14.0 mm)

Key

Key is not included; inspect and reuse or replace the original shaft key as required

Quantity

1 impeller

Construction

Rubber impeller with a metal center insert

What’s in the Box

• 1 x Water pump impeller

Not included: shaft key, water pump housing, gaskets, seals, or other service components.

Installation Notes

1. Confirm the engine model, year, horsepower, stroke, and the dimensions of the original impeller before beginning work.
2. Disconnect the battery and follow the manufacturer’s service procedure for removing the lower unit.
3. Remove the water pump housing cover and take out the old impeller.
4. Inspect the housing, wear plate, shaft, key, gaskets, and seals for damage or wear. Replace worn service parts as needed.
5. Clean debris from the housing and install the replacement impeller with the original or replacement key correctly seated in the shaft keyway.
6. Lubricate the impeller and housing with a lubricant approved for marine water pump components. Do not run the impeller dry.
7. Reinstall the housing cover and lower unit using the manufacturer’s tightening sequence and torque specifications.
8. Test the engine in a suitable water supply and confirm a steady cooling-water discharge before normal operation.

Troubleshooting & FAQ

Safety & Important Information

• Always follow the engine manufacturer’s service instructions and use the correct torque specifications.
• Do not operate the engine without an adequate water supply.
• Inspect the complete water pump assembly whenever the impeller is replaced.
• This is an aftermarket replacement and is not manufactured by Evinrude, Johnson, OMC, BRP, Sierra, Mallory, GLM, SEI Marine, or CEF.