Water Pump Impeller Kit – Fits Johnson Evinrude 5.5HP 6HP 7.5HP (Replaces 763758, 778166, 391391, 382797)

Product Details

This Water Pump Impeller Kit is designed for Johnson Evinrude OMC outboard engines, specifically fitting 5.5HP (1954–1979), 6HP (1954–1979), and 7.5HP (1954–1958) models equipped with plastic pump housings. It delivers reliable water circulation to prevent overheating and maintain optimal engine performance.

This kit directly replaces OEM part numbers 763758, 778166, 391391, and 382797, offering broad cross-compatibility for older two-stroke models.

• Complete rebuild kit with impeller, housing, seals, gaskets, and hardware
• Compatible with Johnson Evinrude plastic pump housing systems
• Suitable for freshwater and saltwater applications

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Technical Specs

OEM Part Number

763758

Replaces

778166, 391391, 382797

Application

Johnson Evinrude OMC Outboards

Housing Type

Plastic Pump Housing

Compatible HP Range

5.5 HP, 6 HP, 7.5 HP

Year Range

1954–1979 (varies by model)

What's in the Box

This package is not listed in the provided data. Please refer to the eBay description for details.

Installation Notes

1. Disconnect fuel line and remove engine cowling to access the water pump assembly.
2. Drain any residual water from the lower unit and remove the lower unit mounting bolts.
3. Separate the lower unit from the mid-section, taking care not to damage gasket surfaces.
4. Remove the old impeller, housing, wear plate, and gaskets from the water pump cavity.
5. Clean all mating surfaces thoroughly, removing old gasket material and debris.
6. Install the new wear plate, ensuring proper alignment with bolt holes.
7. Lubricate the new impeller with water-resistant grease and insert it into the housing, aligning the key slot.
8. Install the pump cup and water seal according to orientation marks.
9. Place the new gasket on the mating surface and carefully reassemble the lower unit to the mid-section.
10. Torque mounting bolts to manufacturer specifications in a crossing pattern.
11. Reconnect fuel line, reattach cowling, and test water flow with engine running in a test tank or on muffs.

Troubleshooting & FAQ

How do I know if my water pump needs replacement?

Common signs include weak or no water discharge from the tell-tale, engine overheating, steam from the exhaust, or reduced performance. Impellers should be inspected annually and replaced every 2–3 years or sooner in sandy or debris-heavy water.

Will this kit fit models with metal pump housings?

No, this kit is designed exclusively for Johnson Evinrude models with plastic pump housings. Verify your housing material before ordering to ensure proper fitment.

Can I install this kit myself?

Installation requires basic mechanical skills and hand tools. If you are comfortable removing the lower unit and working with gaskets and seals, this is a manageable DIY project. Professional installation is recommended if you lack experience with outboard servicing.

What is the difference between this kit and the OEM version?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.

How often should I replace the water pump impeller?

Most manufacturers recommend replacing the impeller every 2–3 years or 200–300 hours of operation. If your engine runs in sandy, silty, or saltwater conditions, consider annual replacement to prevent overheating damage.

Do I need any additional parts or tools?

This is a complete rebuild kit with all essential components. You may need a lower unit gasket set if your engine model uses additional seals. Standard hand tools, a torque wrench, and water-resistant grease are recommended for installation.

What should I do if the kit does not fit my engine?

Verify images/specifications against your original part. If anything differs—even if your model appears compatible—contact support before installation. Returns are accepted within our standard window (unused and in original condition).

Shipping speed & cost?

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns?

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

• Verify images/specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component.
• Professional installation is recommended for safety and performance.

About Sea Sierra

• Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
• Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
• Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.