Balmar 100A Spindle Mount Alternator Kit, J10 Pulley

The Balmar 100A Spindle Mount Alternator Kit includes a 621-100-J10 alternator, MC-618 regulator, temperature sensors and hardware.

Spindle mount covers two different arrangements, and the kit suits both: 1-inch Motorola-style and 2-inch Delco-style. One inch is typical of Westerbeke, Lehman, Hino and Pathfinder engines. Two inches appears on Volvo Penta gas and diesel, John Deere, Perkins and MerCruiser, so the engine rather than the brand decides which applies.

The J10 ten-groove serpentine pulley suits engines already converted to serpentine drive. An engine still on V-belts needs either the dual deep-V version or a pulley conversion kit, since a serpentine alternator pulley cannot run a V-belt.

The kit combines the alternator with external regulation, temperature sensing and mounting hardware. That completeness is the point, because a high-output alternator without a regulator and sensors will not charge properly and may damage itself. Explore more marine alternators.

• Spindle mount covers 1-inch and 2-inch arrangements
• The engine decides, not the brand
• J10 suits engines already on serpentine drive
• A V-belt engine needs a conversion kit first