277181;434424 Water Pump Impeller for Evinrude Johnson | JLM Marine

277181;434424 Water Pump Impeller for Evinrude Johnson | JLM Marine

This high-performance water pump impeller is precision-engineered for Johnson and Evinrude outboard motors ranging from 3 HP to 7.5 HP, covering model years from the early 1950s through the early 1980s. Built with marine-grade neoprene rubber and a brass insert, this impeller ensures reliable cooling system performance in demanding saltwater and freshwater environments.

This replacement impeller directly replaces OEM part numbers 277181 and 434424, as well as aftermarket equivalents including Sierra 18-3001 and CEF 500350. It features a 6-blade design optimized for efficient water flow and long service life.

• Includes: 1 × Neoprene Impeller
• Material: Corrosion-resistant neoprene rubber with brass shaft insert
• Compatible with Johnson/Evinrude 3, 4, 5, 5.5, 6, and 7.5 HP outboards (specific year ranges apply)

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 Serial Number Guide.

Technical Specifications

Package Contents

Your package includes:

• 1 × Outboard Impeller (Neoprene with brass insert)

Installation Guide

1. Disconnect the fuel line and battery to ensure safety during the installation process.
2. Remove the lower unit from the outboard motor according to your engine's service manual.
3. Access the water pump housing by removing the retaining bolts and separating the housing cover.
4. Remove the old impeller carefully, noting the direction of the blade rotation for proper installation.
5. Inspect the pump housing and wear plate for scoring, corrosion, or damage; replace if necessary.
6. Apply a thin layer of water-resistant grease to the new impeller blades and inside the pump housing.
7. Install the new impeller with blades oriented in the correct rotational direction, ensuring the keyway aligns with the driveshaft.
8. Reassemble the water pump housing, ensuring all gaskets and O-rings are properly seated and lubricated.
9. Reinstall the lower unit onto the motor, torquing all fasteners to manufacturer specifications.
10. Reconnect the fuel line and battery, then perform a water flow test before launching.
11. Run the engine in a test tank or on muffs to verify proper water discharge from the telltale outlet.
12. Inspect for leaks around the lower unit and ensure consistent water flow at idle and higher RPMs.

Troubleshooting & FAQ

Q: How do I confirm this impeller fits my Johnson or Evinrude motor?
A: Cross-reference your engine's horsepower and model year with the compatibility table above. If your motor uses OEM part numbers 277181 or 434424, this impeller is the correct replacement. For 4 HP motors built between 1973–1983, ensure your water pump uses a single water tube configuration.

Q: How often should I replace my water pump impeller?
A: Most manufacturers recommend replacing the impeller every 2–3 years or every 200–300 hours of operation, whichever comes first. If you operate in sandy or debris-filled water, inspect the impeller annually and replace at the first sign of cracking, missing blades, or loss of flexibility.

Q: What are the signs that my impeller is failing?
A: Common symptoms include reduced or no water flow from the telltale (indicator stream), engine overheating, steam from the engine, or visible damage to impeller blades during inspection. Replace immediately if any of these signs appear to prevent engine damage.

Q: Can I use this impeller in saltwater applications?
A: Yes, this impeller is constructed from marine-grade neoprene rubber and corrosion-resistant brass, making it suitable for both freshwater and saltwater use. Always flush your cooling system with fresh water after saltwater operation to extend component life.

Q: Is this an OEM or aftermarket part?
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.