Impeller Kit – Fits Westerbeke Marine Generators 3.0-9.6 kW (Replaces 32620, 032620, 23-3305, 09-45589, 132-0311)
Impeller Kit – Fits Westerbeke Marine Generators 3.0-9.6 kW (Replaces 32620, 032620, 23-3305, 09-45589, 132-0311) is backordered and will ship as soon as it is back in stock.
Worry-free returns
Worry-free returns
Shop with confidence. If you’re not completely satisfied, eligible items may be returned within the return window, provided they are unused and in original packaging.
If the return is due to our error or a defective item, we’ll make it right.
Please contact us before returning any item.
Delivery and Shipping
Delivery and Shipping
Orders are typically processed within 1–2 business days.
U.S. orders usually arrive within 6–15 days, depending on stock location and destination.
International delivery times may vary due to customs processing.
Tracking information will be provided once your order ships.
Impeller Kit – Fits Westerbeke Marine Generators 3.0-9.6 kW (Replac...
Impeller Kit – Fits Westerbeke Marine Generators 3.0-9.6 kW (Replaces 32620, 032620, 23-3305, 09-45589, 132-0311) is backordered and will ship as soon as it is back in stock.
Product Details
This Impeller Kit – Fits Westerbeke Marine Generators 3.0-9.6 kW is an essential maintenance component for the raw water cooling system on various gasoline-powered Westerbeke marine generators. It ensures proper engine cooling by replacing the original worn or damaged impeller, preventing overheating and potential engine damage.
This kit serves as a direct replacement for Westerbeke part number 32620/032620, as well as equivalents from Sierra (23-3305), Johnson Pump (09-45589/09-808B), and Onan (132-0311).
- Designed for direct installation in the raw water cooling system.
- Features a durable Neoprene impeller with a slotted shaft pin drive.
- Includes a new gasket, O-rings, and pump cover screws for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Westerbeke | 32620 / 032620 |
| Sierra | 23-3305 / 233305 |
| Johnson Pump | 09-45589 / 09-808B |
| Onan | 132-0311 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This impeller kit fits a wide range of gasoline Westerbeke marine generators, including BCG, BCGB, BCGTC, BTG, WMD, and BCDT series models from 3.0 to 9.6 kW.
| Brand | Model | Rated kW | Frequency | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Westerbeke | 3.0 BCG | 3.0 | 50Hz | 32620 | - |
| Westerbeke | 4.0 BCG | 4.0 | 60Hz | 32620 | - |
| Westerbeke | 3.75 BCG | 3.75 | 50Hz | 32620 | - |
| Westerbeke | 4.5 BCG | 4.5 | 60Hz | 32620 | - |
| Westerbeke | 3.75 BCGB | 3.75 | 50Hz | 32620 | - |
| Westerbeke | 4.5 BCGB | 4.5 | 60Hz | 32620 | - |
| Westerbeke | 3.75 BCGTC | 3.75 | 50Hz | 32620 | - |
| Westerbeke | 4.5 BCGTC | 4.5 | 60Hz | 32620 | - |
| Westerbeke | 4.8 BCG | 4.8 | 50Hz | 32620 | - |
| Westerbeke | 6.5 BCG | 6.5 | 60Hz | 32620 | - |
| Westerbeke | 5.0 BCG | 5.0 | 50Hz | 32620 | - |
| Westerbeke | 7.0 BCG | 7.0 | 60Hz | 32620 | - |
| Westerbeke | 5.0 BCGA | 5.0 | 50Hz | 32620 | - |
| Westerbeke | 7.0 BCGA | 7.0 | 60Hz | 32620 | - |
| Westerbeke | 6.0 BCGB | 6.0 | 50Hz | 32620 | - |
| Westerbeke | 7.0 BCGB | 7.0 | 60Hz | 32620 | - |
| Westerbeke | 6.0 BCGTC | 6.0 | 50Hz | 32620 | - |
| Westerbeke | 7.2 BCGTC | 7.2 | 60Hz | 32620 | - |
| Westerbeke | 7.0 BTG | 7.0 | 50Hz | 32620 | - |
| Westerbeke | 9.0 BTG | 9.0 | 60Hz | 32620 | - |
| Westerbeke | 8.0 BCGTC | 8.0 | 50Hz | 32620 | - |
| Westerbeke | 9.6 BCGTC | 9.6 | 60Hz | 32620 | - |
| Westerbeke | 2.4 WMD | 2.4 | 50Hz | 32620 | - |
| Westerbeke | 3.0 WMD | 3.0 | 60Hz | 32620 | - |
| Westerbeke | 3.5 BCDT | 3.5 | 50Hz | 32620 | - |
| Westerbeke | 3.8/4.2 BCDT | 3.8/4.2 | 60Hz | 32620 | - |
This kit is also cited as compatible with certain Onan models using part number 132-0311.
| Brand | Model | OEM Part No. | Notes |
|---|---|---|---|
| Onan | MAJB | 132-0311 | - |
| Onan | MME | 132-0311 | - |
| Onan | MCE | 132-0311 | - |
| Onan | MDKUB/WB | 132-0311 | - |
Technical Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Direct replacement, raw water cooling system
- Impeller Material
- Neoprene
- Dimensions
- Impeller diameter: 40mm (1.57"), Width: 19.05mm (0.75")
- Weight
- 50g (0.11 lb)
- Fitting Type
- Slotted shaft pin drive type
- Other Technical Attributes
- Impeller shaft diameter: 12.7mm (0.5"), 6 blades
What’s in the Box
- 1 x Water Pump Impeller
- 1 x Pump End Cover Gasket Seal
- 1 x Set Pump Cover Screws
- 1 x O-rings
Installation Notes
- Turn off the sea cock (raw water intake valve) and the main power to the generator.
- Locate the raw water pump on your generator and place a rag or shallow pan beneath it to catch any spilled coolant.
- Remove the screws holding the pump's end cover plate. Note their orientation if they are different lengths.
- Carefully pry off the end cover. The old gasket may stick to it.
- Use impeller pulling pliers or two flathead screwdrivers to carefully remove the old impeller from the pump housing. Avoid scratching the housing walls.
- Clean the inside of the pump housing and the end cover, removing any old gasket material, scale, or debris.
- Lubricate the new impeller and the inside of the pump housing with a marine-safe lubricant (like glycerin or dish soap) to ease installation.
- Install the new impeller by pushing it into the housing while turning it in the direction of engine rotation to bend the blades correctly. Verify blade direction from your old impeller.
- Place the new gasket on the pump housing, align the new end cover, and tighten the screws evenly in a star pattern. Do not overtighten.
- Re-open the sea cock, start the generator, and immediately check the pump for leaks and verify water is flowing from the exhaust outlet.
Troubleshooting & FAQ
How do I know if this impeller fits my generator?
The best way is to match your existing part number to the ones listed in our Part Number Matrix (Westerbeke 32620, Sierra 23-3305, etc.). You can also check our compatibility tables for your specific generator model. When in doubt, compare the dimensions of your old impeller (40mm diameter, 19.05mm width) to our specs.
What are the signs of a failing impeller?
Common signs include the generator running hotter than usual, reduced or no water flow from the exhaust outlet, visible cracks or missing blades on the old impeller during inspection, or a noisy water pump.
How often should I replace my generator's water pump impeller?
As a general rule, it's recommended to inspect the impeller annually and replace it every 1-2 years or every 200-300 running hours, whichever comes first. Usage in sandy or silty water may require more frequent replacement.
Is this impeller made of the same material as the original?
This impeller is made of Neoprene, a robust and flexible material widely used for marine water pump impellers due to its durability and resistance to chemicals and temperature changes. It is a common material for both OEM and high-quality aftermarket parts.
OEM vs. Aftermarket?
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.
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 vs 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.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
