Water Pump Impeller 388702 for Johnson Evinrude Outboard Motors – 20-35 HP
This high-performance water pump impeller is designed as a direct replacement for Johnson and Evinrude 2-stroke outboard motors ranging from 20 HP to 35 HP. Engineered with marine-grade neoprene rubber and brass insert, it delivers reliable cooling performance across a wide range of applications from 1978 and newer models.
This impeller directly replaces OEM part numbers 388702, 47-89982, 47-65958, 395289, and 395265, as well as aftermarket equivalents including Sierra 18-3051 and CEF 500370, ensuring broad compatibility and easy sourcing.
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6-blade neoprene impeller with brass insert for durability and corrosion resistance
- Fits multiple horsepower ratings across decades of Johnson Evinrude 2-stroke engines
- Precision-engineered dimensions for direct OEM replacement fitment
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
Notes |
| Johnson / Evinrude (OEM) |
388702 |
Primary OEM number |
| Johnson / Evinrude (OEM) |
47-89982 |
OEM alternate |
| Johnson / Evinrude (OEM) |
47-65958 |
OEM alternate |
| Johnson / Evinrude (OEM) |
395289 |
OEM alternate |
| Johnson / Evinrude (OEM) |
395265 |
OEM alternate |
| Sierra |
18-3051 |
Aftermarket equivalent |
| CEF |
500370 |
Aftermarket equivalent |
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/Evinrude Serial Number Guide.
| Brand |
Rated HP |
Stroke |
Years |
| Johnson Evinrude |
20 HP |
2 Stroke |
1982 & UP |
| Johnson Evinrude |
25 HP |
2 Stroke |
1979 & UP |
| Johnson Evinrude |
28 HP |
2 Stroke |
1978 & UP |
| Johnson Evinrude |
30 HP |
2 Stroke |
1984 & UP |
| Johnson Evinrude |
35 HP |
2 Stroke |
1978 & UP |
Technical Specifications
| Specification |
Value |
| Material |
Neoprene and Brass |
| Number of Blades |
6 |
| Internal / Insert / Hub / Shaft Size |
0.628 inch (16.00 mm) |
| Depth / Height / Width / Thickness |
0.754 inch |
| Overall / Outer / External Diameter |
2.015 inch (51.00 mm) |
| Item Weight |
Approx. 37 g |
Package Contents
Your package includes:
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1 × Outboard Impeller (Neoprene with brass insert)
Installation Guide
- Disconnect the fuel line and remove the lower unit from the outboard motor according to your engine's service manual.
- Remove the water pump housing cover and note the orientation of the old impeller before extraction.
- Carefully extract the old impeller using impeller pullers or needle-nose pliers. Avoid damaging the pump housing.
- Clean the pump housing thoroughly, removing any debris, old gasket material, or corrosion.
- Lubricate the new impeller with water-resistant marine grease or glycerin to ease installation and prevent dry start damage.
- Install the new impeller with blades oriented in the correct rotation direction (consult your service manual for proper rotation).
- Ensure the brass insert is properly seated on the drive shaft and the impeller is fully seated in the housing.
- Replace the pump housing gasket with a new one and apply a thin layer of marine-grade sealant if recommended.
- Reinstall the water pump housing cover and torque bolts to manufacturer specifications.
- Reattach the lower unit to the engine, ensuring proper alignment and secure mounting.
- Reconnect the fuel line and test the cooling system by running the engine with a water supply (flush muffs or in-water test).
- Check for proper water discharge from the tell-tale indicator and verify no leaks around the pump housing.
Troubleshooting & FAQ
Q: How do I confirm this impeller fits my Johnson or Evinrude engine?
A: Cross-reference your engine's horsepower, model year, and stroke type with the compatibility table above. You can also verify by matching the OEM part number (388702, 395289, 47-89982, etc.) found in your engine's parts diagram or service manual.
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 frequently operate in sandy or debris-filled water, inspect and replace more often.
Q: What are the signs that my impeller is failing?
A: Common symptoms include weak or no water flow from the tell-tale indicator, engine overheating, steam from the engine, or reduced cooling performance. Inspect the impeller immediately if any of these occur.
Q: Can I install this impeller myself or do I need a professional?
A: If you have mechanical experience and the proper tools, installation is straightforward following the service manual. However, professional installation is recommended to ensure proper fitment, correct blade orientation, and to avoid damage to the pump housing.
Q: Is this an OEM or aftermarket impeller?
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.