Yanmar KMH4A Gear R 2.04 for JH3-DTE / JH4-TE – KMH4AS is a marine transmission component designed for integration with Yanmar diesel propulsion systems that utilize an inboard reduction gearbox. It serves as the mechanical interface between the engine and the propeller shaft, transferring engine output in sailboats and auxiliary powerboats operating with inboard diesel installations. This unit forms part of an OEM Yanmar marine propulsion configuration and is intended for standard marine drivetrain layouts where accurate alignment and controlled power transfer are required.
This gearbox is configured with a 2.04 reduction ratio and is compatible with Yanmar JH3-DTE and JH4-TE diesel engines specified for KMH4A-series gear applications. The reduction ratio supports balanced propeller shaft speed and torque characteristics suitable for typical marine operating conditions. When installed in accordance with manufacturer specifications, it integrates with approved engine mounts, controls, and shafting systems without modification as an OEM Yanmar marine gearbox replacement.
This Yanmar marine gearbox is typically used for replacement of existing transmissions, repower projects involving compatible JH-series engines, or new marine installations requiring an OEM Yanmar marine propulsion transmission matched to a defined drivetrain configuration.
