Balmar Serpentine Pulley Kit for Yanmar 4JH, 4JHE

Description

The Balmar AltMount Serpentine Pulley Conversion Kit is designed for Yanmar 4JH and 4JHE-series diesel engines, including the TE, HTE, and DTE variants. It converts the engine accessory drive to a J10 ten-groove serpentine system that can transfer more alternator load than a conventional single-V-belt arrangement.

Higher-output alternators require additional mechanical power from the engine, and the wider contact area of a ten-rib serpentine belt helps reduce slippage while supporting sustained charging. That makes the conversion particularly useful on cruising boats with larger battery banks and electrical loads that keep the alternator working hard for long periods.

The kit includes three matching J10 pulleys, two 47-inch-circumference serpentine belts, and mounting hardware. One belt is installed and the second can be carried as an onboard spare. Using an engine-specific pulley set helps maintain proper groove alignment and belt tracking during the conversion.

An AT-200A alternator may require a longer belt than the standard 47-inch length supplied. For compatible Yanmar 4JH and 4JHE applications, this Balmar kit provides the major drive components needed to support a high-output J10 alternator system. Take a look through our alternator mounts & pulleys.