JMP Marine JPR-YM08IH2 Yanmar Engine Cooling Raw Water/Seawater Pump Replacement


Sale price$311.38
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With a water pump replacement from Boat & RV Accessories, you can keep your boat's engine from overheating.

Though boats are a completely different class of vehicle, boat engines have a lot of similarities with their automotive brothers and sisters. One of the main differences is temperature regulation. If you think an overheated engine is bad news on a highway, experiencing that on a lake, gulf or other large body of water is even worse.

This JMP Marine water replacement pump is a Yanmar replacement for systems that use raw water or seawater for engine cooling. Built with premium materials, it is made to be easily installed and offers long-lasting, reliable service.

This water pump replacement is for use with specific systems. It is part of a large selection of boat replacement parts and components we offer at low prices. Contact our boating experts today to learn more about whether this water pump will help service your model.

Please Note: JPR-YM08IH2 is ONLY for 2GM or 3GM as seen in compatibility list below. This should NOT be confused with 2GMF or 3GMF models. If you have the 2GMF or 3GMF please refer to JPR-YM08IH and its cross-reference information. If still unsure, please contact us or JMP Marine for more information.

You must use JPR-YM08IH2 pump model to replace Yanmar 128377-42500 as there is a difference in revolutions per minute compared to the JPR-YM08IH (Flow rate of JPR-YM08IH is greater vs JPR-YM08IH2) which some have thought is compatible for both this Yanmar number and 128397-42500, this is not true. Please use JPR-YM08IH2 to replace Yanmar 128377-42500.

Q: What is the internal difference between JPR-YM08IH2 and model JPR-YM08IH?

A: The difference is the thickness of the machined "Cam" which is incorporated or part of the Body / Casing itself. The machined cam thickness is less (2mm) for JPR-YM08IH2 vs a larger thickness (4mm) found in the JPR-YM08IH. This is why it is very important to order the correct pump for your model of engine by referring the cross-reference information provided.


  • Plug & Play Replacement
  • Simple & Compact Design (Less Parts)
  • Strong Bronze Body (Heavy Duty Marine Grade Casting)
  • High Performance and Long Life Flexible Impellers
  • Marine Grade Shaft (3X Series Non-Magnetic)
  • Mechanical Seal instead of Lip Seal
  • Heavy Duty Machined Steel Pulley
  • Cam-Less Design / Cam is machined in the Body Casing
  • Compatible Engine Models: 2GM 3GM


  • (1) JPR-YM08IH2 (Yanmar Replacement Pump)
  • (1) Steel Pulley and Mounting bracket


  • Genuine Yanmar Pump 128377-42500
  • Johnson Pump 10-24509-02
  • Johnson Pump F4B-902


jmp impeller 7050-01K
major service kit JSK0082
minor service kit JSM0091
port size 1/2" Hose (Inner Diameter)
pump size 91 x 114 x 76 mm
pump weight 4.0 lbs

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