Yanmar Marine Diesel Engines

The single-, twin- and three-cylinder GM series (such as the 1GM10, 2GM20 and 3GM30) and the newer YM series (2YM, 3YM) are the classic auxiliary diesels for cruising and racing sailboats in roughly the 9 to 40 HP range. They are light, compact and simple — exactly what an auxiliary engine should be — and parts and rebuild support remain strong.

These engines are typically paired with a Kanzaki/Yanmar marine gear (such as the KM2 or KM3) and a saildrive or shaft installation. We confirm the gear ratio, drive type and cooling so your replacement matches the existing engine bed and shaft alignment.

The four-cylinder JH series (such as the 4JH family) covers roughly 40 to 110+ HP and powers larger cruising sailboats, motorsailers and small powerboats. Modern common-rail and turbocharged versions deliver more power with low noise and excellent efficiency, while older naturally aspirated and turbo 4JH engines are abundant and well supported.

JH engines pair with marine gears in various ratios for shaft or saildrive setups. We help you confirm the exact 4JH variant, rating, gearbox and cooling configuration so the new engine matches your installation.

A used running Yanmar take-out is the most economical option when your gearbox and mounts are good. Rebuilt engines renew worn parts; remanufactured engines are machined back to spec with new internals for near-new life. Diesels are durable, so even a well-maintained used Yanmar can deliver many more reliable hours.

Every Yanmar carries a 6-month warranty with extended coverage available, ships nationwide by freight, and is typically sold on core exchange. Tell us your model, hours, gearbox and cooling type for a free, exact quote.