Water Pump Impeller Kit – Fits Johnson/Evinrude 20-35 HP (Replaces 393630)

Water Pump Impeller Kit – Fits Johnson/Evinrude 20-35 HP (Replaces 393630)

This water pump impeller kit is designed for Johnson/Evinrude 20-35 HP, 2-stroke outboard motors from 1980 and newer. It provides a reliable solution for maintaining your engine’s cooling system to prevent overheating and ensure optimal performance.

It serves as a direct replacement for Johnson/Evinrude part number 393630 / 0393630 and also interchanges with Sierra 18-3382, GLM 12960, Mallory 9-48300, and CEF 500350.

• Engine Fitment: Johnson/Evinrude 20, 25, 30, & 35 HP (2-Stroke, 1980-Up)
• Installation Type: Direct replacement for OEM components.
• Kit Contents: Includes impeller, housing, wear plate, gaskets, seals, and all necessary hardware for a complete overhaul.

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 Neoprene Impeller (395289)
• 1 x Impeller Key (330619)
• 1 x Gasket (325537)
• 1 x Wear Plate (328755)
• 1 x Pump (328751)
• 1 x Pump Housing (393632)
• 1 x Grommet (302497)
• 1 x Brass Bushing (328754)
• 4 x O-ring (311338 x 2 / For Bushing 301877 / 554545)
• 1 x Seal (328753)
• 6 x Washer (324960 / 318452)

Installation Guide

1. Safety First: Disconnect the engine's battery and remove the spark plug wires.
2. Access the Lower Unit: Remove the bolts securing the lower unit (gearcase) to the engine leg and carefully lower it. You may need to disconnect a shift linkage.
3. Remove Old Pump: Unscrew the bolts on the top of the water pump housing and slide the entire assembly off the driveshaft.
4. Disassemble and Clean: Take note of the order of all components. Remove the old impeller, wear plate, gaskets, and seals. Thoroughly clean all mounting surfaces, removing any old gasket material or corrosion.
5. Install New Components: Place the new gasket and wear plate onto the lower unit. Slide the new impeller key into its slot on the driveshaft.
6. Install Impeller: Coat the new impeller and the inside of the new housing with a marine-grade lubricant. Slide the impeller onto the driveshaft while turning the shaft clockwise to bed the vanes correctly.
7. Secure New Housing: Install the new gasket and pump housing, ensuring all seals are correctly seated. Tighten the bolts to the manufacturer-specified torque.
8. Reinstall Lower Unit: Carefully guide the lower unit back into place, ensuring the driveshaft, water tube, and shift shaft align. Re-secure with bolts.
9. Final Checks: Reconnect the shift linkage and battery. Start the engine in water and immediately verify a steady stream of water is exiting the tell-tale port.

Troubleshooting & FAQ

How do I confirm this kit fits my Johnson/Evinrude engine?
First, check the "Compatible Engine Models" table above. This kit is designed for 20, 25, 30, and 35 HP 2-stroke models made from 1980 onwards. For further confirmation, you can use the official Johnson/Evinrude serial number guide linked above to identify your exact model and year, then cross-reference the OEM part number 393630.

What are the signs that my water pump is failing?
The most common signs of a failing water pump are a weak or inconsistent stream of water from the "telltale" indicator, or the engine overheating alarm sounding. Reduced engine performance, especially at higher speeds, can also indicate a cooling problem.

How often should I replace my water pump impeller?
As a critical part of preventative maintenance, it is recommended to inspect the impeller annually and replace it completely every 1-2 years or 100-200 hours of use. This interval should be shortened if you operate primarily in saltwater or sandy/silty conditions.

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.
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• Professional installation is recommended to ensure safety and optimal performance.
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• 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.