Impeller Kit – Fits Westerbeke Marine Gas Generators 3.0-9.6 (Replaces Westerbeke, Johnson, Onan 32620, 09-45589, 132-0311)
Impeller Kit – Fits Westerbeke Marine Gas Generators 3.0-9.6 (Replaces Westerbeke, Johnson, Onan 32620, 09-45589, 132-0311) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
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Impeller Kit – Fits Westerbeke Marine Gas Generators 3.0-9.6 (Repla...
Impeller Kit – Fits Westerbeke Marine Gas Generators 3.0-9.6 (Replaces Westerbeke, Johnson, Onan 32620, 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 Gas Generators 3.0-9.6 (Replaces 32620) is an essential component for the sea water cooling system in various Westerbeke Marine Gas Generators. It is designed for a broad range of models, including those from the 3.0 BCG to the 9.6 BCGTC series, covering both 50Hz and 60Hz versions commonly used for electrical power generation on marine vessels.
This kit provides a direct interchange for multiple part numbers, including Sierra 23-3305, QuickMarine 32620, StayCoolPumps SCP-32620, Westerbeke 32620, Johnson 09-45589, and Onan 132-0311.
- Engineered for direct replacement into the sea water cooling pump.
- Features a durable blade made from High Speed Steel for reliable performance.
- This Sierra-equivalent part is backed by a lifetime warranty.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket providers.
| Brand | Part Number |
|---|---|
| Sierra | 23-3305 |
| QuickMarine | 32620 |
| StayCoolPumps | SCP-32620 |
| Westerbeke | 32620 |
| Johnson | 09-45589 |
| Onan | 132-0311 |
Engine & Model Compatibility
Confirm your engine model in the table below to ensure correct fitment.
| 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 Specs
- Product Type
- Water Pump Impeller Kit
- Installation
- Replacement for sea water cooling system
- Housing Color
- White
- Blade Material
- High Speed Steel
- 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)
What’s in the Box
- 1 x Impeller
- 1 x Gasket
- 4 x Screws
- 1 x O-Ring
- 2 x Seals
Installation Notes
- Ensure the engine is off and cool. Close the seawater intake valve (sea cock).
- Place an absorbent pad under the pump to catch any spilled coolant.
- Remove the screws holding the sea water pump's cover plate.
- Gently pry off the cover plate. Note the orientation of the old impeller.
- Remove the old impeller using needle-nose pliers or impeller pullers. Avoid scoring the pump housing.
- Clean any debris and old gasket material from the housing and cover plate surfaces.
- Lightly lubricate the new impeller and pump housing interior with water-resistant grease or soapy water.
- Install the new impeller, bending the blades in the direction of the pump's normal rotation.
- Place the new gasket or O-ring onto the cover plate.
- Reattach the cover plate and tighten the screws in a star pattern to ensure even pressure. Do not overtighten.
- Open the seawater intake valve.
- Start the engine and immediately check for leaks and verify strong water flow from the exhaust outlet.
Troubleshooting & FAQ
How do I know if my impeller needs replacing?
Signs of a failing impeller include engine overheating, a noticeable reduction in water flow from the exhaust, visible cracks or missing blades, or stiffness in the rubber. It is recommended to inspect the impeller annually or according to your engine manufacturer's service schedule.
Will this fit my specific Westerbeke generator model?
This kit is designed for a wide range of Westerbeke gas generators (3.0-9.6 models). To guarantee compatibility, please refer to our "Engine & Model Compatibility" table and cross-reference your generator's model and original part number (32620).
What is the difference between this impeller and the original OEM part?
This aftermarket impeller kit is built to meet or exceed original equipment manufacturer (OEM) specifications for performance, material durability, and fit. It offers a reliable, cost-effective alternative to the genuine Westerbeke part without compromising quality.
Is any special lubricant required for installation?
A light coating of soapy water or marine-grade water-resistant grease on the impeller and inside the pump housing will ease installation and provide initial lubrication on startup. Do not use petroleum-based lubricants, which can damage the impeller material.
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.
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