# Balmar Alternator 120 AMP 12V 1-2" Single Foot Spindle Mount J10 Pulley w/Isolated Ground [621-120-J10]

**Alternator 120 AMP 12V 1-2" Single Foot Spindle Mount J10 Pulley with Isolated Ground**

Alternator, 621 Series, 120A, 12V, Spindle Mount (Single Foot), 1-2in, J10 AltMount Serpentine Pulley, Isolated Ground 1" Motorola-Style Mounting.

Typical for Westerbeke, Lehman, Hino & Pathfinder Engines 2" Delco-Style Mounting;  Typical for Volvo Penta (Gas & Diesel), John Deere, Perkins, Mercruiser, Pleasurecraft, Crusader, Indmar, Marine Power & other GM-based Engines.

Replaces: 621-120-SR-IG

**This product may not be returned to the original point of purchase. Please contact the manufacturer directly with any issues or concerns.**

**Specifications:**

-   Amperage: 120A
-   Voltage: 12v
-   Box Dimensions: 8"H x 10"W x 10"L WT: 6.9 lbs
-   UPC: 676205751186

  
[Brochure (pdf)](https://productimageserver.com/literature/brochure/97461BR.pdf)

## Details

- **Price:** 904.69 USD
- **Type:** Alternators
- **Tags:** Brand_Balmar, Engine Parts & Service, Engine Parts & Service | Alternators

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Default Title | 904.69 USD | In stock |

## Images

- Balmar Alternator 120 AMP 12V 1-2" Single Foot Spindle Mount J10 Pulley w/Isolated Ground [621-120-J10] Balmar

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> Source: [Besafe1st](https://besafe1st.com/products/balmar-alternator-120-amp-12v-1-2-single-foot-spindle-mount-j10-pulley-w-isolated-ground-621-120-j10)
> Updated: 2026-05-21