Water Pump Impeller Kit – Fits Mercury/Mariner & Johnson/Evinrude 30-70HP (Replaces 46-77177A3)

Water Pump Impeller Kit – Fits Mercury/Mariner & Johnson/Evinrude 30-70HP (Replaces 46-77177A3)

This water pump impeller repair kit is designed for Mercury/Mariner and Johnson/Evinrude 30–70HP 2-stroke outboard engines (1974–1990s). It provides all necessary components for a complete impeller service, excluding the pump housing.

This kit is a direct replacement for Mercury/Mariner part number 46-77177A3 and BRP/Johnson/Evinrude part number 77177A3.

• Installation Type: Direct replacement for OEM components.
• Core Components: Includes the impeller, face plate, gaskets, and seals required for a standard rebuild.
• Important Note: This is a water pump repair kit without the pump housing assembly. Please verify that your existing housing is in good condition before purchase.

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 Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

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 Serial Number Guide.

Technical Specifications

Package Contents

• 1 x Water Pump Impeller
• 1 x Gaskets
• 1 x Drive Key
• 1 x Face Plate
• 1 x Face Seal
• 1 x Seal Carrier
• 1 x Water Tube Coupling
• Note: Pump housing is NOT included in this kit.

Installation Guide

1. Safety First: Disconnect the battery and ensure the engine is securely mounted.
2. Access the Lower Unit: Drain the gearcase lubricant. Remove the bolts securing the lower unit (gearcase) to the engine's midsection.
3. Remove the Old Pump: Carefully slide the lower unit off the driveshaft. The water pump is located on top of the gearcase. Unbolt and remove the old pump housing and impeller assembly.
4. Clean and Inspect: Thoroughly clean the mounting surfaces and inspect the housing for wear, cracks, or warping. If the housing is damaged, it must be replaced.
5. Install New Components: Lightly grease the new seals and gaskets. Install the new drive key, impeller, and face plate as per your engine's service manual.
6. Reassemble: Reinstall the pump housing, ensuring the impeller vanes are correctly oriented. Carefully guide the driveshaft back into the crankshaft splines.
7. Secure Lower Unit: Bolt the lower unit back onto the midsection, torquing the bolts to the manufacturer's specification. Refill the gearcase with fresh lubricant.
8. Test Operation: Reconnect the battery. Start the engine in the water or with a proper flush attachment and verify a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

Q: How do I confirm this kit fits my engine?
A: The best way is to match your existing part number to the ones listed in our cross-reference table (46-77177A3 or 77177A3). Additionally, verify your engine's HP, stroke, and year fall within the ranges specified in the "Compatible Engine Models" table.

Q: What are the signs of a bad water pump impeller?
A: Common symptoms include the engine overheating at idle or low speeds, a weak or non-existent water stream from the "tell-tale" outlet, and in severe cases, steam coming from the exhaust.

Q: How often should I replace the water pump impeller?
A: For preventative maintenance, it is recommended to inspect and/or replace the impeller every 1-2 years or every 100-200 hours of use, depending on operating conditions (e.g., more frequently in saltwater or sandy/silty water).

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.