Water Pump Impeller – Fits Johnson/Evinrude 35-55 HP Outboards (Replaces 377230, 777213)

Water Pump Impeller – Fits Johnson/Evinrude 35-55 HP Outboards (Replaces 377230, 777213)

This aftermarket water pump impeller is designed for Johnson/Evinrude 35-55 HP 2-Stroke outboard motors (1958–1978), including models with 35, 40, 50, and 55 horsepower ratings. It serves as a direct replacement part to maintain your engine's cooling system.

Engineered to meet or exceed OEM specifications, this impeller ensures reliable water flow for optimal engine temperature regulation. It is a direct replacement for Johnson/Evinrude part numbers 377230, 777213, and 777821.

• Material: Constructed from high-quality neoprene rubber with a durable brass hub for enhanced corrosion resistance.
• Installation Method: Installs directly into the water pump housing as a replacement for the original part.
• Primary Function: A crucial component of the engine cooling system, responsible for pumping raw water.

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 (377230/777213)

Explosion Diagram

Installation Guide

1. Safety First: Before starting, disconnect the engine's battery and disable the ignition system.
2. Access the Lower Unit: Remove the lower unit (gearcase) from the outboard motor. This typically involves removing several bolts connecting it to the midsection.
3. Open the Water Pump Housing: Locate the water pump on top of the lower unit and remove the bolts securing its cover.
4. Remove the Old Impeller: Carefully slide the old impeller off the driveshaft. Pay attention to the direction of the vanes, as the new one must be installed the same way.
5. Clean and Inspect: Thoroughly clean the inside of the water pump housing and the base plate. Inspect for any scoring, warping, or corrosion. Replace the housing if significant wear is found.
6. Install the New Impeller: Apply a thin layer of marine grease to the inside of the pump housing and slide the new impeller onto the driveshaft, rotating the shaft in its normal direction of operation to bend the vanes correctly.
7. Reassemble: Reinstall the water pump cover, gaskets, and seals, ensuring all components are seated correctly. Torque bolts to the manufacturer’s specifications.
8. Reinstall Lower Unit: Reattach the lower unit to the outboard motor.
9. Test Operation: Reconnect the battery. Start the engine in the water or with a proper flush attachment and confirm that a steady stream of water is exiting the tell-tale port.

Troubleshooting & FAQ

How do I confirm this fits my engine?
First, check the "Compatible Engine Models" table on this page. Cross-reference your outboard's brand, model, horsepower, and year. Second, compare the part numbers listed in the "Part Number Cross-Reference" section with your existing part number. Finally, visually compare our product photos with your old part to ensure a match.

How often should I replace the water pump impeller?
For preventative maintenance, it is recommended to inspect the impeller annually and replace it every 1-2 years, depending on usage (hours) and water conditions (salt, silt, sand). If the engine overheats or the water stream from the tell-tale weakens, inspect it immediately.

What are the signs of a failing impeller?
Common signs include the engine running hotter than normal, an engine overheat alarm, or a weak or non-existent stream of water from the "tell-tale" outlet port. Brittle, cracked, or missing vanes on the impeller itself are definitive signs that it needs replacement.

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.