Impeller Kit – Fits Westerbeke Marine Generators 3.0-9.6 kW (Replaces 32620, 032620)
This water pump impeller kit is designed for a range of Westerbeke marine generators, including gasoline-powered models from 3.0 kW to 9.6 kW (both 50Hz and 60Hz versions). It serves as a direct replacement part for the raw water cooling system, ensuring your generator maintains optimal operating temperatures.
This kit is a direct replacement for Westerbeke 32620 / 032620, Sierra 23-3305 / 233305, Johnson Pump 09-45589 / 09-808B, and Onan 132-0311.
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Installation Method: Installs as a direct replacement in the raw water cooling system pump.
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Core Component: The flexible impeller is made from durable Neoprene.
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Complete Kit: Includes the impeller, gasket, o-ring, and screws for service.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Westerbeke |
32620 / 032620 |
| Sierra |
23-3305 / 233305 |
| Johnson Pump |
09-45589 / 09-808B |
| Onan |
132-0311 |
Compatible Engine Models
Confirm your engine model/year in the table below.
Westerbeke Marine Generators
| Brand |
Model |
Rated kW |
Frequency |
OEM Part No. |
| 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 |
Other Equipment
| Brand |
Model |
OEM Part No. |
| Onan |
MAJB |
132-0311 |
| Onan |
MME |
132-0311 |
| Onan |
MCE |
132-0311 |
| Onan |
MDKUB/WB |
132-0311 |
Technical Specifications
| Specification |
Value |
| 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 |
Package Contents
- 1 x Water Pump Impeller (Replaces 32620, 032620, Sierra 23-2001)
- 1 x Pump End Cover Gasket Seal (Replaces 24826)
- 1 x Set Pump Cover Screws (Replaces 34463)
- 1 x O-ring (Replaces 46624)
- Marine Seals with 316SS Garter Springs (Quantity not specified)
Installation Guide
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Safety First: Turn off the engine and disconnect the battery. Close the water inlet seacock to prevent water from entering the boat.
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Locate Pump: Identify the raw water pump on your generator.
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Access Impeller: Remove the pump's end cover screws to expose the impeller. Place a tray or rag underneath to catch any spilled water.
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Remove Old Impeller: Use needle-nose pliers or an impeller puller to carefully extract the old impeller from the housing.
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Clean Housing: Inspect the pump housing for debris or damage. Clean the interior surfaces and ensure all pieces of the old impeller are removed.
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Prepare New Impeller: Lightly lubricate the new impeller and the inside of the pump housing with a water-based lubricant or glycerine. Do not use petroleum grease.
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Install New Impeller: Insert the new impeller by gently squeezing the blades and pushing it into the housing with a slight twisting motion that follows the direction of engine rotation.
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Replace Gasket and Cover: Install the new gasket or O-ring, ensuring it is seated correctly. Secure the end cover with the new screws, tightening them evenly in a crisscross pattern.
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Final Checks: Re-open the seacock. Reconnect the battery, start the engine, and immediately check for leaks and proper water flow.
Troubleshooting & FAQ
Q: How can I confirm this impeller fits my specific generator model?
A: Please review the "Compatible Engine Models" table on this page. Cross-reference your generator's model number and, if possible, the OEM part number stamped on your existing impeller (e.g., 32620 for Westerbeke). Verifying the impeller dimensions (40mm diameter, 19.05mm width) against your old part is also a reliable check.
Q: What are the signs that my impeller needs to be replaced?
A: Common signs of a failing impeller include the engine overheating, reduced water flow from the exhaust outlet, visible cracks or missing blades on the impeller, and a stiff or brittle texture. Regular inspection is key.
Q: How often should I replace my generator's water pump impeller?
A: For optimal reliability, we recommend replacing the impeller annually or every 100-200 operating hours, whichever comes first. Proactive replacement helps prevent unexpected overheating and engine damage.
Q: OEM vs. Aftermarket?
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.