Impeller Kit – Fits Westerbeke Marine Gas Generators 3.0-9.6 (Replaces 32620)
This impeller kit is designed for a wide range of Westerbeke Marine Gas Generators, from the 3.0 BCG to the 9.6 BCGTC models. It serves as a crucial component for the sea water cooling system, ensuring your generator operates at a safe temperature.
This kit is a direct replacement for several OEM and aftermarket part numbers, including Sierra 23-3305, Westerbeke 32620, Johnson 09-45589, and Onan 132-0311, among others listed in the cross-reference table below.
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Installation: Installs in the sea water cooling system pump.
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Complete Kit: Includes the impeller, gasket, o-ring, seals, and screws for a full replacement.
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Blade Material: Features a durable High Speed Steel blade.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Sierra |
23-3305 |
| QuickMarine |
32620 |
| StayCoolPumps |
SCP-32620 |
| Westerbeke |
32620 |
| Johnson |
09-45589 |
| Onan |
132-0311 |
Compatible Engine Models
Confirm your engine model/year in the table below.
| Brand |
Model |
Rated HP |
OEM Part No. |
Notes |
| Westerbeke |
3.0 WMD (60Hz) |
3.0 |
32620 |
|
| Westerbeke |
2.4 WMD (50Hz) |
2.4 |
32620 |
|
| Westerbeke |
3.8/4.2 BCDT (60Hz) |
3.8/4.2 |
32620 |
|
| Westerbeke |
3.5 BCDT (50Hz) |
3.5 |
32620 |
|
| Westerbeke |
4.0 BCG (60Hz) |
4.0 |
32620 |
|
| Westerbeke |
3.0 BCG (50Hz) |
3.0 |
32620 |
|
| Westerbeke |
4.5 BCG (60Hz) |
4.5 |
32620 |
|
| Westerbeke |
3.75 BCG (50Hz) |
3.75 |
32620 |
|
| Westerbeke |
4.5 BCGB (60Hz) |
4.5 |
32620 |
|
| Westerbeke |
3.75 BCGB (50Hz) |
3.75 |
32620 |
|
| Westerbeke |
4.5 BCGTC (60Hz) |
4.5 |
32620 |
|
| Westerbeke |
3.75 BCGB (50Hz) |
3.75 |
32620 |
Also listed as BCGTC in some sources |
| Westerbeke |
6.5 BCG (60Hz) |
6.5 |
32620 |
|
| Westerbeke |
4.8 BCG (50Hz) |
4.8 |
32620 |
|
| Westerbeke |
7.0 BCG (60Hz) |
7.0 |
32620 |
|
| Westerbeke |
5.0 BCG (50Hz) |
5.0 |
32620 |
|
| Westerbeke |
7.0 BCGA (60Hz) |
7.0 |
32620 |
|
| Westerbeke |
5.0 BCGA (50Hz) |
5.0 |
32620 |
|
| Westerbeke |
7.0 BCGB (60Hz) |
7.0 |
32620 |
|
| Westerbeke |
6.0 BCGB (50Hz) |
6.0 |
32620 |
|
| Westerbeke |
7.2 BCGTC (60Hz) |
7.2 |
32620 |
|
| Westerbeke |
6.0 BCGTC (50Hz) |
6.0 |
32620 |
|
| Westerbeke |
9.0 BTG (60Hz) |
9.0 |
32620 |
|
| Westerbeke |
7.0 BTG (50Hz) |
7.0 |
32620 |
|
| Westerbeke |
9.6 BCGTC (60Hz) |
9.6 |
32620 |
|
| Westerbeke |
8.0 BCGTC (50Hz) |
8.0 |
32620 |
|
Technical Specifications
| Specification |
Value |
| Product Type |
Water Pump Impeller Kit |
| Installation |
Replacement for sea water cooling system |
| Housing Color |
White |
| Dimensions |
6 × 2.5 × 6 inches (152.4 × 63.5 × 152.4 mm) |
| Weight |
1.28 ounces (36.3 g) |
| Fitting Type |
Universal Fit |
| Warranty |
Lifetime Warranty (Sierra) |
| Other Technical Attributes |
High Speed Steel blade material |
Package Contents
- 1 x Impeller
- 1 x Gasket
- 4 x Screws
- 1 x O-Ring
- 2 x Seals
Installation Guide
Follow these general steps to replace the impeller. Always consult your generator’s service manual for model-specific instructions.
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Safety First: Turn off the generator and disconnect its power source. Close the water intake seacock to prevent water from entering the vessel.
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Access the Pump: Locate the sea water pump on your generator and remove the cover plate, which is typically held on by several screws.
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Remove Old Impeller: Carefully pull out the old impeller. You may need impeller pullers or two screwdrivers to gently pry it out. Note the direction of the blades.
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Clean Housing: Clean the inside of the pump housing, removing any debris or old gasket material. Inspect the housing for any scoring or damage.
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Install New Seals/Gasket: Install the new O-ring or gasket included in the kit. Ensure it is seated correctly.
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Install New Impeller: Lightly lubricate the new impeller and the inside of the housing with a suitable marine lubricant. Insert the new impeller with a twisting motion, ensuring the blades are bent in the correct direction of the pump's rotation.
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Reassemble: Replace the cover plate and tighten the screws evenly in a crisscross pattern to ensure a good seal.
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Final Check: Re-open the seacock. Start the generator and immediately check the pump for any water leaks and verify that water is flowing through the cooling system.
Troubleshooting & FAQ
Q: How do I confirm this impeller kit fits my generator?
A: This kit is designed for a wide range of Westerbeke gas generators from 3.0 to 9.6 kW. The best way to confirm fitment is to match your existing part number to one of the numbers listed in our Part Number Cross-Reference table, such as Westerbeke 32620 or Sierra 23-3305. You can also check your model against the Compatible Engine Models list.
Q: What are the common signs of a failing water pump impeller?
A: Key signs include the generator overheating, a reduced or no flow of water from the exhaust outlet, visible cracks or missing blades on the old impeller, or a hardened and inflexible impeller material. Regular inspection is recommended.
Q: How often should I replace the impeller?
A: As a general guideline, it is recommended to inspect the impeller annually and replace it every 1-2 years, depending on usage hours and operating conditions (e.g., water quality). Always replace it if you notice any signs of wear or 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.