Water Pump Impeller Kit with Key and Gasket – Fits Johnson/Evinrude 5.5–7.5 HP (Replaces 763735, 387361)
Water Pump Impeller Kit with Key and Gasket – Fits Johnson/Evinrude 5.5–7.5 HP (Replaces 763735, 387361) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Water Pump Impeller Kit with Key and Gasket – Fits Johnson/Evinrude...
Water Pump Impeller Kit with Key and Gasket – Fits Johnson/Evinrude 5.5–7.5 HP (Replaces 763735, 387361) is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Water Pump Impeller Kit with Key and Gasket is designed as a replacement for Johnson/Evinrude 5.5 HP and 6 HP two-stroke outboard engines from 1954–1979, and 7.5 HP two-stroke outboard engines from 1954–1958. It is intended for engines equipped with the original metal water pump housing and helps restore proper water circulation through the cooling system.
This kit replaces or interchanges with Johnson/Evinrude part numbers 763735, 0763735, 387361, 0387361, 777831, and 0777831; Sierra 18-3090; Mallory 9-45210; GLM 89490; and SEI 96-399-02.
- For compatible models using the original metal water pump housing.
- Includes one rubber impeller, one housing gasket, and one drive shaft key.
- Direct-fit replacement design for service of the existing water pump assembly.
Part Number Matrix
Use the following references to compare the original and aftermarket numbers for your application.
| Brand | Part Number |
|---|---|
| Johnson/Evinrude | 763735 / 0763735 |
| Johnson/Evinrude | 387361 / 0387361 |
| Johnson/Evinrude | 777831 / 0777831 |
| Sierra | 18-3090 |
| Mallory | 9-45210 |
| GLM | 89490 |
| SEI | 96-399-02 |
Engine & Model Compatibility
Confirm the engine horsepower, year, two-stroke configuration, original part number, and water pump housing style before ordering.
| Brand | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Johnson/Evinrude | 5.5 HP | 2-Stroke | 1954–1979 | 763735 / 0763735 | For models with metal pump housing |
| Johnson/Evinrude | 6 HP | 2-Stroke | 1954–1979 | 763735 / 0763735 | For models with metal pump housing |
| Johnson/Evinrude | 7.5 HP | 2-Stroke | 1954–1958 | 763735 / 0763735 | For models with metal pump housing |
Technical Specs
- Product Type
- Water pump impeller kit
- Installation
- Direct replacement
- Connection
- Direct shaft connection
- Impeller Material
- Rubber
- Application
- Existing metal water pump housing
- Overall Diameter
- 38.80 mm
- Height
- 18.60 mm
- Shaft Diameter
- 11.20 mm
- Weight
- 40 g (0.04 kg)
- Fitting Type
- Direct fit with shaft key
- Blades/Vanes
- 6
What’s in the Box
- 1 × Water pump impeller
- 1 × Impeller housing gasket
- 1 × Drive shaft key
The metal water pump housing is not included. Reuse your existing compatible housing if it is serviceable.
Installation Notes
- Disconnect the spark plug leads and shift the outboard into neutral.
- Remove the lower unit mounting bolts and carefully separate the lower unit from the upper housing.
- Remove the water pump housing cover to access the old impeller.
- Note the old impeller blade direction, then remove the impeller and drive key from the shaft.
- Clean the pump housing interior and all mating surfaces thoroughly.
- Install the supplied drive key in the shaft and slide the new impeller into position.
- Apply a thin coat of suitable marine grease to the inside of the pump housing to assist installation.
- Install the new gasket, refit the housing, and tighten the fasteners according to the engine manufacturer’s specifications.
- Reinstall the lower unit, ensuring that the driveshaft and water tube are correctly aligned.
- Test the assembled engine in water and confirm a strong, steady cooling-water stream from the tell-tale outlet.
Troubleshooting & FAQ
How do I know if this impeller fits my engine?
This kit is intended for Johnson/Evinrude 5.5 HP and 6 HP two-stroke outboards from 1954–1979 and 7.5 HP two-stroke outboards from 1954–1958 that use the specified metal water pump housing. Verify your engine’s exact model and year, original part number, and housing style before ordering.
What are the signs of a failing water pump impeller?
Common signs include a weak or absent tell-tale stream, overheating, or steam from the exhaust. A worn impeller may also show cracking, brittleness, deformation, or missing blades.
How often should I replace my impeller?
Inspect the impeller regularly and replace it when it shows wear or as part of scheduled preventative maintenance. Service intervals should be shortened when the engine is operated in saltwater or sandy or silty water.
What tools are needed for installation?
You will typically need a socket or wrench set, screwdrivers, a gasket scraper or plastic blade, and suitable marine grease. Refer to the engine service manual for model-specific tools and torque specifications.
Does this kit include the metal pump housing?
No. The kit includes the rubber impeller, housing gasket, and drive shaft key. It is designed for installation in your existing compatible metal pump housing.
What is the difference between this and an OEM part?
This is an aftermarket replacement, not an OEM component. It is designed to provide the specified fit, form, and function for the listed applications.
Is this an OEM part?
No. This listing is for an aftermarket replacement kit. The OEM and aftermarket reference numbers shown above are provided for application and cross-reference purposes.
Shipping speed and cost
Worldwide shipping is available. Typical transit time is 5–15 days; available shipping methods and any applicable charges are shown at checkout.
Warranty and returns
This product is covered by a 1-year warranty against manufacturing defects under normal use. Returns are accepted within the applicable standard return period when the item is unused and in its original condition. Contact support with your order details for assistance.
Safety & Important Info
- Verify the engine model, year, stroke, horsepower, original part number, and water pump housing style before purchase.
- Compare the replacement part with the removed component before installation. Do not install it if the dimensions or configuration differ.
- This is an aftermarket replacement, not an OEM component.
- Follow the engine service manual and use qualified installation assistance when needed.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts designed for dependable service in real-world operating conditions.
- Fast Global Fulfillment — Free standard delivery is available to most regions, with typical transit of 5–15 days.
- Manufacturer-Direct Value — Fair pricing with attention to materials and quality control.
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