48V High Power Alternator

The Dual Foot (Saddle) Mounts: Yanmar vs. Volvo

3.15-inch (80mm) Saddle Mount: This is often called the “Yanmar style” mount. It has a 3.15-inch distance between the inside edges of the two mounting feet. This is standard on most Yanmar engines and many other Japanese-built marine engines. This also includes the Nanni engine (like the N4.38 or N4.40), which are built on Kubota engine blocks. Kubota, being a Japanese manufacturer like Yanmar, uses the same Yanmar-style mounting configuration.

4-inch (~108mm) Saddle Mount: This is common on many Volvo Penta models, as well as engines from North American manufacturers like Cummins, Crusader and Mercruiser. Your measurement of 4.25″ is within the typical range for this style, though it’s most commonly referred to as the 4-inch mount.