Water Pump Impeller Kit – Fits Johnson/Evinrude 40-75 HP (Replaces 389133, 387326, 18-3325)

Water Pump Impeller Kit – Fits Johnson/Evinrude 40-75 HP

This water pump impeller kit is engineered for Johnson/Evinrude 40-75 HP 2-Stroke outboard engines, covering models from 1960–1997. It is designed with a specific focus on 2-cylinder and 3-cylinder Loopcharged models manufactured between 1975 and 1988.

This kit serves as a direct replacement for multiple OEM and aftermarket part numbers, including Johnson/Evinrude 389133, 387326, 387217, GLM 12232, and Sierra 18-3325.

• Designed for direct OEM replacement installation.
• Manufactured to meet or exceed original equipment specifications.
• The core component is the water pump impeller, crucial for engine cooling.

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

The kit typically includes:

• 1 x Water Pump Impeller (389133)

Installation Guide

1. Safety First: Before starting, disconnect the engine's battery terminals to prevent accidental starting.
2. Access the Lower Unit: Shift the outboard into neutral. Remove the bolts securing the lower unit (gearcase) to the upper engine housing.
3. Remove the Lower Unit: Gently lower the gearcase away from the engine. The driveshaft will disengage from the powerhead.
4. Open the Water Pump: Locate the water pump housing on top of the gearcase. Remove the bolts securing the housing cover.
5. Extract the Old Impeller: Lift off the housing and slide the old impeller off the driveshaft. Note the direction of the vanes as you remove it. Clean any debris from the housing and wear plate.
6. Install the New Impeller: Lightly lubricate the new impeller and the inside of the housing. Slide the new impeller onto the driveshaft, turning the shaft clockwise to set the vanes in the correct direction.
7. Reassemble the Pump: Replace any gaskets and O-rings (if included in your kit). Securely bolt the housing back into place.
8. Reinstall the Lower Unit: Carefully guide the driveshaft, water tube, and shift shaft back into place and bolt the lower unit to the engine.
9. Test Operation: Reconnect the battery. With the outboard in water or connected to a proper flush device, start the engine and verify a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this impeller kit fits my Johnson/Evinrude engine?
A: First, check the Compatible Engine Models table to see if your HP and year range are listed. This kit is primarily for 40-75 HP 2-Stroke models (1960-1997) and specifically for 2-cyl/3-cyl Loopcharged models (1975-1988). The most reliable method is to cross-reference your engine's original part number with those listed, such as 389133 or 387326.

Q: What are the signs of a failing water pump impeller?
A: The most common signs of a worn or damaged impeller are the engine overheating at idle or low speeds, and a weak or inconsistent water stream from the "tell-tale" cooling system outlet. In severe cases, the engine can overheat quickly, causing significant damage.

Q: How often should I replace the water pump impeller?
A: For preventative maintenance, it is highly recommended to inspect the impeller annually and replace it every 1-2 years or 100-200 hours of use. Replacement frequency should be increased if you operate primarily in saltwater or in water with heavy sediment.

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.