JPR-YM08IH Aftermarket Yanmar 2GM/3GM/2YM/3YM Seawater Pump | Sawley's Select Marine Parts

🔧 Product Description

Aftermarket JMP Yanmar 2GM/3GM/2YM/3YM seawater pump - Replacement Part Number: JPR-YM08IH

A compact engine-mounted bronze seawater pump for Yanmar GM- and YM-series marine diesels. It replaces the 128397-42500/128377-42500/128990-42500 pump family and cross-references to Johnson 10-24509-01 and 10-13337-01.

⚙️ Key Features

• Engine-mounted bronze flexible-impeller pump

• Mounting bracket included

• Suitable for GM- and YM-series engines listed below

• Cross-references to Johnson F4B-903 pump family

• Serviceable impeller, seals and shaft components

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• Yanmar 128397-42500 / 128990-42500 → Later related references for 128377-42500 on specified engines

• Johnson 10-24509-01 and 10-13337-01 / F4B-903 are original pump cross-references

OEM / Related Numbers:

• JPR-YM08IH

• Yanmar 128397-42500

• Yanmar 128377-42500

• Yanmar 128990-42500

• Johnson 10-24509-01

• Johnson 10-13337-01

• Johnson F4B-903

Aftermarket / Verified Equivalents:

• JMP Marine: JPR-YM08IH

Included Components:

• Complete seawater pump - Part Number: JPR-YM08IH

• Mounting bracket - supplied

🚤 Compatibility

Commonly used on:

• Flexible-impeller raw-water cooling systems

Typically suits:

• Engine models:

• Yanmar 2GM and 2GM20F

• Yanmar 3GM and 3GM30F

• Yanmar 2YM15

• Yanmar 3YM20 and 3YM30

• HP Range: Approximately 13HP-30HP

• Engine Type: Yanmar GM/YM two- or three-cylinder marine diesel

• Year Range: Model-specific; confirm OEM pump 128397-42500, 128377-42500 or 128990-42500

• Pump Pattern: Johnson F4B-903 family

🔌 Function

The seawater pump draws raw water through the intake and circulates it through the engine, heat exchanger, oil cooler, aftercooler and wet-exhaust circuit as applicable. Its flexible impeller must maintain adequate flow from idle through full load while the shaft, bearings and mechanical seal keep the drive and water sections correctly supported and separated.

Common signs of failure:

• Engine temperature rises under load or at higher RPM

• Reduced or intermittent water discharge from the exhaust

• Missing, cracked, swollen or permanently set impeller vanes

• Seawater leakage or salt tracks from the shaft seal or weep area

• Bearing noise, pulley or gear wobble, or excessive shaft movement

• Scored cover plate, worn cam or damaged pump housing reduces suction

• Internal corrosion, air leakage or blocked inlet passages cause loss of prime

📦 Condition

• Brand new aftermarket replacement part

• New and unused

• Supplied in manufacturer or equivalent protective packaging