Water Pump Impeller – Fits Jabsco, Johnson, Yanmar 2GM/3GM Series (Replaces 128990-42200)

Water Pump Impeller – Fits Jabsco, Johnson, Yanmar 2GM/3GM Series (Replaces 128990-42200)

This high-quality neoprene water pump impeller is designed for select Yanmar, Jabsco, and Johnson marine pumps. It serves as a direct replacement for Yanmar 128990-42200 and is compatible with Yanmar 2GM20 and 3GM30 series engines manufactured between 1981 and 2003, as well as newer YM series engines.

This impeller directly replaces OEM and aftermarket part numbers including Yanmar 128990-42200, Jabsco 18653-0001/18653-0001-P, Johnson 09-810B/09-810B-1, Sierra 18-45713, Mallory 9-45713, Volvo 876097, CEF 500101, and JMP 7050-01.

• Engineered with a durable neoprene body and a brass insert for reliable performance.
• Features 6 blades and a slotted shaft pin drive design for a precise fit.
• Designed for internal engine cooling pumps.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below.

Yanmar Engines

Jabsco Pumps

Johnson Pumps

Westerbeke Engines

Technical Specifications

Package Contents

• 1 x Impeller (Replaces 128990-42200)

Installation Guide

1. Safety First: Ensure the engine is off and cool. Close the water inlet seacock and disconnect the battery.
2. Locate Pump: Find the raw water pump on your engine. Place a rag or container underneath to catch any spilled water.
3. Remove Cover Plate: Unscrew the bolts holding the pump's cover plate. Keep track of the screws and any gasket.
4. Extract Old Impeller: Use impeller pullers or two pliers to grip the hub of the old impeller and pull it straight out. Avoid damaging the pump housing.
5. Clean Housing: Inspect the inside of the pump for debris or worn parts. Clean it thoroughly.
6. Lubricate: Apply a small amount of water-resistant grease or dish soap to the inside of the housing and to the new impeller.
7. Install New Impeller: Insert the new impeller by pushing it in while rotating the shaft in its normal direction of operation. This will bend the blades correctly.
8. Replace Gasket & Cover: Install a new gasket if your kit includes one. Secure the cover plate, tightening the screws in a star pattern to ensure an even seal.
9. Final Checks: Reconnect the battery and open the seacock. Start the engine and immediately check the pump for leaks. Ensure water is flowing out of the exhaust.

Troubleshooting & FAQ

Q: How do I know if this impeller fits my specific engine model?
A: The best way to confirm fitment is to check your original part number against our cross-reference list. You can also consult our compatibility tables for Yanmar, Jabsco, Johnson, and Westerbeke models. Verifying the impeller dimensions—Diameter: 51mm (2"), Width: 22mm (7/8")—is also a reliable method.

Q: What are the signs of a failing water pump impeller?
A: Common signs include engine overheating, reduced water flow from the exhaust outlet, visible cracks or missing blades on the old impeller, and a stiff or brittle texture. Regular inspection is key.

Q: How often should I replace my engine's water pump impeller?
A: Most engine manufacturers recommend replacing the impeller every 1-2 years or every 100-200 hours of use, whichever comes first. For boats used in saltwater or sandy conditions, more frequent replacement is advisable.

Q: Is there a difference between neoprene and nitrile impellers?
A: Yes. This impeller is made of neoprene, which is suitable for engine cooling systems where water is the primary fluid. Nitrile impellers are typically used for oil and fuel transfer pumps, as they are more resistant to petroleum products.

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?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.