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Yanmar Gearbox

KMH51A

8-degree down-angle hydraulic Kanzaki gear rated at 457 Nm with 1.67 to 2.60:1 ratios, the marine gear for Yanmar's 6BY3 engines.

The KMH51A uses the larger KMH50A housing (41 kg dry without oil cooler, damper or feet, 2.0 L of oil, Borg-Warner bell housing) with a 457 Nm input rating. Yanmar's operation manual lists ratios of 1.67, 2.13, 2.43 and 2.60:1.

Yanmar's BY3 operation manual names the KMH51A (or the V-drive KMH50V) for the 6BY3-220 and 6BY3-260, and the 2020 gear table adds the 6BY3-160.

Sources

  1. 1. KMH40A-KMH51A Marine Gear Operation Manual (0AKMH-EN0014, 2019.11) — Yanmar
  2. 2. BY3 Series Operation Manual (0ABY0-G00301) — Yanmar
  3. 3. Kanzaki Gears product page with gear/engine applicability table (2020 capture) — Yanmar Marine International

Specifications compiled from manufacturer sources.