Impeller Kit - Fits Westerbeke Marine Diesel Generators & Engines (Replaces 48500, 048500)

Product Details

This aftermarket Impeller Kit for Westerbeke Marine Diesel Generators & Engines is engineered for reliable raw water cooling performance. It is designed to fit Westerbeke marine diesel generators equipped with Sea Water Pump models 48080/048080 and 37431/037431, covering a range from 5.7 BTD to 15.0 BTDC, along with various marine diesel engines from the 12C Two to the 44C Four series.

This kit serves as a direct cross-reference for Westerbeke 48500 and 048500; StayCoolPumps SCP-48500; SOXAMarine 48500; QuickMarine 48500; and North Boatparts 48500.

• Primary Material: Flexible and durable Neoprene with 6 blades for optimal water flow.
• Installation Type: Installs in the marine raw/sea water cooling system pump.
• Complete Kit: Includes the impeller, O-ring, gaskets, and mounting screw for a full replacement.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Engine & Model Compatibility

Confirm your engine model in the tables below. This kit fits a wide range of Westerbeke marine diesel generators and engines.

Westerbeke Marine Diesel Generators:

Westerbeke Marine Diesel Engines:

Technical Specs

Product Type

Water Pump Impeller Kit

Installation

Marine Raw/Sea Water Cooling System

Impeller Material

Neoprene

Number of Blades

6

Impeller Diameter

50.8 mm (2.0 inches)

Impeller Height

22 mm (0.88 inch)

Shaft Diameter

12 mm (0.47 inch)

Fitting Type

Slotted Shaft Pin Drive

Warranty

1 Year (North Boatparts)

What’s in the Box

• 1 x Water Pump Impeller (Replaces 48500/048500)
• 1 x O-Ring (Replaces 48359)
• 1 x Screw (Replaces 34463)
• 2 x Gaskets

Installation Notes

Important Fitment Note: This kit is compatible with Westerbeke pumps manufactured from March 2004 or later, which feature the new style round 6-bolt cover. It will NOT fit older pump model 33636, which can be identified by a cover that is scalloped at the 4 and 8 o'clock positions. Please verify your pump style before ordering.

1. Shut off the engine and close the raw water intake valve (sea cock).
2. Remove the screws securing the water pump cover plate.
3. Carefully pry off the cover plate and remove the old O-ring or gasket.
4. Using pliers or an impeller puller, remove the old impeller from the pump housing.
5. Clean any debris or old gasket material from the pump housing and cover plate.
6. Lightly lubricate the new impeller with water-based lubricant (e.g., dish soap) and install it into the housing with a twisting motion in the direction of engine rotation.
7. Place the new gasket or O-ring onto the pump body, install the cover plate, and tighten the screws evenly.
8. Open the sea cock, start the engine, and immediately check for any leaks around the pump cover.

Troubleshooting & FAQ

Safety & Important Info

• Verify images and specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
• This is an aftermarket replacement, not an OEM component. Brand names and part numbers are used for reference purposes only.
• Professional installation is recommended for safety and performance. Incorrect installation can lead to engine damage.

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 quality control.