Water Pump Impeller – Fits Johnson/Evinrude 40HP (Replaces 390286, 0390286, 777835, 0777835)

Water Pump Impeller – Fits Johnson/Evinrude 40HP (Replaces 390286, 0390286, 777835, 0777835)

This water pump impeller is designed for specific Evinrude and Johnson Outboard 40HP 2-Stroke engines manufactured between 1983 and 1986. It serves as a direct replacement, ensuring reliable performance for your engine's cooling system.

It is a direct replacement for Johnson/Evinrude part numbers 390286, 0390286, 777835, and 0777835, as well as several other aftermarket equivalents.

• Installation Method: Direct replacement
• Material: Constructed from durable, high-quality neoprene rubber for longevity.
• Package Options: Available as an impeller only or as a kit with the impeller key pin included.

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.

Evinrude Outboard Models

Johnson Outboard Models

Technical Specifications

Package Contents

Please check the part number you are ordering carefully. Package contents vary:

• If you order part number with a "K" suffix (e.g., Soxa Marine 17IO016K):
  This package contains both the impeller and the key pin.
  • 1 x Water Pump Impeller (replaces 390286)
  • 1 x Impeller Key Pin (replaces 0305350/0308928/0777849/308924/308928)
• If you order part number without a "K" suffix (e.g., Soxa Marine 17IO016):
  This package contains the impeller ONLY.
  • 1 x Water Pump Impeller (replaces 390286)

Installation Guide

1. Disconnect the negative battery cable for safety.
2. Unbolt and carefully slide the lower unit (gearcase) off the outboard's driveshaft housing.
3. Locate and unbolt the water pump housing cover to expose the impeller.
4. Note the rotational direction of the old impeller's blades before removing it.
5. Remove the old impeller, any gaskets, and the small key pin from the driveshaft.
6. Thoroughly clean the impeller housing and wear plate surfaces.
7. Insert the new key pin into the slot on the driveshaft.
8. Lightly lubricate the new impeller with marine grease and slide it onto the shaft, aligning it with the key pin.
9. Reinstall the water pump housing, ensuring the impeller blades are curved in the correct rotational direction.
10. Tighten the housing bolts to the manufacturer's recommended torque specifications.
11. Re-install the lower unit onto the outboard and reconnect the battery cable.
12. Start the engine using a water supply (flushing muffs) and verify a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

How do I know if this impeller will fit my 40HP Johnson engine?
This impeller fits specific Johnson and Evinrude 40HP 2-Stroke outboards made from 1983 to 1986. To ensure a perfect match, please consult the "Compatible Engine Models" table on this page and cross-reference your engine's model number before ordering.

What is the difference between the 'K' and non-'K' versions?
The part numbers are designed to give you purchasing options. Part numbers ending in "K" (like 17IO016K) are a kit that includes both the water pump impeller and the corresponding key pin. Part numbers without the "K" suffix include only the impeller.

What are the signs of a failing water pump impeller?
Common signs of a worn or damaged impeller include the engine overheating at idle or low speeds, a weak or intermittent water stream from the "tell-tale" outlet, and finding brittle, cracked, or broken rubber pieces in the water pump housing during inspection.

How often should the impeller be replaced?
For preventative maintenance and to avoid overheating, we recommend inspecting the impeller annually and replacing it every 1-2 years. Replacement frequency depends on usage hours and the type of water (saltwater, freshwater, or 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.
• 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.