Balmar 120A Spindle Mount Alternator Kit, Dual Vee Pulley

The Balmar 120A Spindle Mount Alternator Kit includes a 621-120-DV alternator with dual deep-V pulley, for 1-inch Motorola or 2-inch Delco mountings.

Spindle mount rather than saddle mount is the distinction, and it covers single-foot arrangements instead of dual-foot. One inch is typical of Westerbeke, Lehman, Hino and Pathfinder engines; two inches is the Delco-style arrangement. The engine decides, and a saddle-mount alternator will not fit either.

The dual deep-V pulley suits twin V-belt drives rather than a serpentine belt. That matters because a 120A alternator asks a lot of a belt, and two V-belts spread the load where one would slip under full output.

The kit includes the alternator, external regulation, temperature sensing and hardware as a coordinated package. Isolated grounding keeps return current in its own cable rather than through the engine block and bonding system. Explore more marine alternators.

• Spindle mount is single-foot, not dual-foot saddle
• 1-inch Motorola or 2-inch Delco style
• Dual deep-V spreads the load across two belts
• One belt would slip under 120A output