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Raw Water Pump Impeller – Fits Yanmar 2GM, 3GM Series (Replaces 128296-42070, 124223-42091)

Sale price $24.50 Regular price $39.00
Shipping calculated at checkout.

Raw Water Pump Impeller – Fits Yanmar 2GM, 3GM Series (Replaces 128296-42070, 124223-42091) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This is a direct replacement Raw Water Pump Impeller – Fits Yanmar 2GM, 3GM, 2GM20F, 3GM30F Series (Replaces 128296-42070, 124223-42091), engineered for reliable performance in various Yanmar marine engines and Kohler marine generators. It's designed for Yanmar models including the 2GM, 3GM, 2GM20F, 3GM30F, 2QM, 3QM, and 3HM series, as well as Kohler generator models 8E, 10E, 12.5E, and 12.5CF (SN 296898 and below).

This impeller serves as an aftermarket equivalent for numerous part numbers, including Yanmar 128296-42070 and 124223-42091, Jabsco 22799-0001, Johnson 09-824P-9, and Kohler 250872.

  • Installs as a direct replacement for compatible models.
  • Features a durable key drive insert for secure shaft engagement.
  • JMP kits include a gasket and lubricant for a complete installation.

Part Number Matrix

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

Brand Part Number
Yanmar 128296-42070
Yanmar 124223-42091
Yanmar 124223-42092
Yanmar 124223-42090
Yanmar 128296-42040
Jabsco 22799-0001
Johnson 09-824P-9
Johnson 09-827
Johnson 09-827B
Kohler 250872
Kohler 229955
Kohler 229955KIT
Kohler 252475
Sierra 18-8950
Sierra 23-2003
Sierra 23-3304
CEF 500129
CEF 500238
VETUS IMP00101
ANCOR J050016
JMP 7052-01

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Yanmar engines, note that this impeller will not fit European-made models manufactured in 1997 or later.

For Kohler generators, compatibility is limited to units with a serial number of 296898 and below.

Brand Model Rated HP Years OEM Part No. Notes
Yanmar 2GM, 2GMF 1980–1983 124223-42091
Yanmar 3GM, 3GMF, 3GMDF 1980–1983 124223-42091
Yanmar 2GM20F, 2GM20FVE 20 1983–2005 124223-42091 Will not fit 1997 and later European made models
Yanmar 3GM30F, 3GM30FVE 30 1983–2005 124223-42091 Will not fit 1997 and later European made models
Yanmar 2QM, 2QM20 128296-42070
Yanmar 3QM, 3QM30 128296-42070
Yanmar 3HM, 3HMF 1980–1983 128296-42070
Yanmar 3HM35, 3HM35F, 3HM35C 1983–1992 128296-42070
Kohler 8E 250872/229955 SN 296898 and below
Kohler 10E 250872/229955 SN 296898 and below
Kohler 12.5E 250872/229955 SN 296898 and below
Kohler 12.5CF 250872/229955 SN 296898 and below

Technical Specs

Product Type
Marine Raw Water Pump Impeller
Installation
Direct replacement
Connection
Key drive
Dimensions
51 mm diameter × 22 mm width (2" × 7/8")
Shaft Diameter
12.7 mm
Number of Blades
6
Insert Type
Key drive
Key Width
5.25 mm (approximate)
Insert Material
Brass (JMP version)
Impeller Material
Neoprene or Nitrile (varies by brand)
Weight
0.15 lbs (0.068 kg)
Warranty
1-2 years (varies by manufacturer)

What’s in the Box

  • 1 × Flexible Impeller (Replaces Yanmar 124223-42091/128296-42070/124223-42092)
  • 1 × Gasket (GAK0031) (JMP kit only)
  • 1 × Lubricant (JMP kit only)

Installation Notes

  1. Close the raw water seacock to prevent water from entering the vessel.
  2. Access the raw water pump housing and remove the cover plate screws.
  3. Carefully remove the old impeller. Use impeller pullers or two screwdrivers to gently pry it out. Avoid scoring the housing.
  4. Clean the inside of the pump housing, removing any old debris or impeller fragments.
  5. Apply a small amount of the supplied lubricant to the inside of the housing and to the new impeller.
  6. Insert the new impeller, bending the blades in the correct direction of the pump's rotation.
  7. Install the new gasket (if included) and replace the pump cover plate, tightening the screws evenly.
  8. Open the raw water seacock.
  9. Start the engine and immediately check the pump and exhaust for proper water flow and for any leaks.

Troubleshooting & FAQ

How do I confirm this impeller fits my engine?

The best way is to cross-reference your existing impeller's part number with the numbers in our Part Number Matrix. Also, verify your engine model and year falls within the ranges listed in the compatibility table. Be aware this part does not fit Yanmar models made in Europe from 1997 onwards.

What are the signs of a failing water pump impeller?

Common symptoms include the engine running hotter than normal, a complete overheating alarm, or a noticeable reduction in water flow from the exhaust outlet. A visual inspection may reveal cracked, brittle, or missing blades.

How often should I replace my impeller?

As a preventative maintenance item, most marine mechanics and engine manufacturers recommend replacing the raw water pump impeller annually or every 200-300 hours of use, whichever comes first. Always consult your engine's service manual for specific intervals.

What's the difference between Neoprene and Nitrile impellers?

Neoprene is the most common material and is suitable for most raw water cooling applications where only trace amounts of oil are present. Nitrile impellers offer superior resistance to oil, fuel, and chemicals, making them ideal for bilge pumps or in engine cooling systems where contamination is a risk.

Does this kit include a gasket and lubricant?

The package contents vary by brand. The JMP branded kits include one impeller, one gasket, and a packet of lubricant. For other brands, please check the "What's in the Box" section for specific inclusions.

Is this an OEM part or aftermarket?

This listing is for an aftermarket replacement part, not an original equipment manufacturer (OEM) component. It has been engineered to meet or exceed OEM specifications using comparable materials and is manufactured in an ISO 9002 certified facility with batch inspections for quality assurance.

What are the shipping speed and cost?

We ship worldwide quickly, with typical transit times of 5–15 days for most regions. Standard shipping is free. Expedited shipping options, if available for your location, will be presented at checkout.

What is the warranty and return policy?

This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition. See our full policy page or contact us 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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