Water Pump Impeller Kit with Housing – Fits Johnson/Evinrude 20–35 HP 2-Cylinder Outboards (Replaces OEM 393630)
Water Pump Impeller Kit with Housing – Fits Johnson/Evinrude 20–35 HP 2-Cylinder Outboards (Replaces OEM 393630) is backordered and will ship as soon as it is back in stock.
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Water Pump Impeller Kit with Housing – Fits Johnson/Evinrude 20–35 ...
Water Pump Impeller Kit with Housing – Fits Johnson/Evinrude 20–35 HP 2-Cylinder Outboards (Replaces OEM 393630) is backordered and will ship as soon as it is back in stock.
Product Details
This water pump impeller kit with housing is an aftermarket replacement for selected Johnson/Evinrude 20–35 HP, 2-cylinder crossflow outboard motors with thru-propeller exhaust and a one-piece gearcase. The documented application range is 1980–2005. It is designed to restore water-pump components that have become worn, brittle, or damaged and to help maintain proper engine cooling.
The kit replaces Johnson/Evinrude/OMC OEM part number 393630. Sierra reference 18-3382 is listed for the same with-housing replacement application. Confirm the engine configuration, gearcase style, model details, and original pump components before ordering.
- Complete water-pump service kit supplied with a replacement housing.
- Includes a neoprene impeller, pump housing, wear plate, pump cup, gaskets, seals, O-rings, key, and installation hardware as listed below.
- Suitable for the specified 2-cylinder crossflow application; it is not a universal fit for every Johnson/Evinrude 20–35 HP engine.
Part Number Matrix
Use these numbers as reference points when comparing the original component and replacement catalog information.
| Brand or Source | Part Number | Application Note |
|---|---|---|
| Johnson/Evinrude/OMC | 393630 | OEM replacement reference |
| Sierra | 18-3382 | With-housing water pump kit reference |
Engine & Model Compatibility
The application information below is based on the documented 393630 replacement relationship. Model-specific suffixes, serial-number breaks, exhaust arrangements, and gearcase configurations can affect fitment. Verify the complete engine model and the original water-pump assembly before installation.
| Brand | Engine Family | Rated HP | Stroke | Years | Gearcase / Exhaust Conditions | OEM Reference |
|---|---|---|---|---|---|---|
| Johnson/Evinrude | 2-cylinder crossflow | 20–35 HP | 2-Stroke | 1980–2005 | Thru-propeller exhaust and one-piece gearcase | 393630 |
Important: The application should not be extended to 3-cylinder 25, 30, or 35 HP models solely by horsepower. Other Johnson/Evinrude engines with thru-cavitation-plate exhaust, a two-piece gearcase, or a different water-pump design may require a different kit.
Technical Specifications
- Product Type
- Water pump impeller kit with housing
- Replacement Type
- Aftermarket replacement for the documented OEM application
- Impeller Material
- Neoprene rubber
- Impeller Design
- 6-blade
- Housing Material
- Metal/aluminum with nylon PA66 plastic components
- Housing Color
- White/silver
- Weight
- 283 g (0.62 lb)
What’s in the Box
- 1 × Neoprene impeller — 395289
- 1 × Impeller key — 330619
- 1 × Gasket — 325537
- 1 × Wear plate — 328755
- 1 × Water pump cup — 328751
- 1 × Pump housing — 393632
- 1 × Grommet — 302497
- 1 × Brass bushing — 328754
- 4 × O-rings, including 311338, 301877, and 554545
- 1 × Seal — 328753
- 6 × Bolts with washers — 324960 / 318452
Component part numbers are provided for identification and comparison. Package appearance and minor hardware details may vary by production batch; verify the supplied parts against the original assembly before installation.
Installation Notes
- Disconnect the spark-plug wires and place the outboard in neutral. Follow the engine manufacturer's safety and service procedures.
- Remove the lower unit or gearcase from the engine midsection.
- Remove the old water-pump housing and note the orientation of the impeller, key, cup, wear plate, seals, and water tube.
- Clean the driveshaft and all mating surfaces. Remove old gasket material without damaging the gearcase.
- Install the supplied grommet, seals, wear plate, gasket, and related pump components in the correct positions.
- Fit the impeller key and impeller to the driveshaft. Rotate the shaft in the direction specified by the engine service information while seating the impeller vanes in the pump cup.
- Install the housing and gasket, then tighten the fasteners to the engine manufacturer's torque specification.
- Reinstall the lower unit, making sure the driveshaft, shift mechanism, and water tube are correctly aligned.
- Test the engine using the proper water source and confirm a strong cooling-water stream before normal operation.
Troubleshooting & FAQ
How do I know if the water-pump impeller needs replacing?
Common signs include overheating at idle or low speed, a weak or missing tell-tale stream, fluctuating cooling-water flow, or an impeller that is cracked, brittle, melted, or has permanently set vanes.
How often should the impeller be replaced?
Replacement timing depends on operating hours, storage conditions, and exposure to saltwater, sand, or silt. Inspect the impeller according to the engine service schedule and replace it whenever wear or damage is found. Many owners inspect it annually as preventive maintenance.
Will this fit a 3-cylinder Johnson/Evinrude 25, 30, or 35 HP engine?
Do not assume it will. This application is documented for 2-cylinder crossflow engines with thru-propeller exhaust and a one-piece gearcase. Verify the full engine model and gearcase configuration before ordering.
Is the housing included?
Yes. This listing is for a water pump impeller kit with housing and includes the pump housing listed in the package contents.
Is this an OEM part?
No. This is an aftermarket replacement intended for the documented OEM 393630 application. Johnson/Evinrude/OMC and Sierra names and part numbers are used only for identification and compatibility reference.
What should I verify before ordering?
Compare the original OEM number, engine model, horsepower, stroke, year, cylinder count, exhaust arrangement, gearcase style, impeller design, and housing configuration. If any of these details differ, consult the appropriate engine parts catalog or a qualified marine technician.
Safety & Important Information
- Disconnect the battery and spark-plug wires and follow the manufacturer's service instructions before working on the outboard.
- Use the correct lifting equipment and support the lower unit securely during removal and installation.
- Do not run the engine without an adequate water supply.
- Confirm the fitment and package contents before installation. A horsepower-only match is not sufficient.
- Professional installation is recommended if you are not familiar with lower-unit removal or water-pump service.
About Sea Sierra
- We supply aftermarket marine replacement parts selected for documented applications.
- Each listing is organized around component references and fitment conditions to help customers compare the replacement with the original part.
- For the best result, provide the complete engine model and original part information when requesting fitment assistance.
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