Motorenfabrik Hatz was founded in 1880 as a mechanical workshop in Ruhstorf an der Rott, Bavaria, Germany, and has remained a family-owned company throughout its history. Over time it developed into a specialist manufacturer of small diesel engines built for industrial and construction use.

Hatz is known for its rugged air-cooled single-cylinder diesel engines, including the L-series and E-series, which have long been used to power construction machinery, generators, welders, pumps, and compressors. The company later expanded into water-cooled diesels with its 2, 3, and 4 cylinder 4H series, designed to meet modern emission standards while keeping the same reputation for durability that the brand built with its earlier single-cylinder models in demanding industrial settings.

The manuals available on this page cover specific Hatz models, including the 2G40, 2W35, 3W35, 3W35T, 4W35, and 4W35T. Typical content includes engine rebuild procedures, electrical systems and wiring diagrams, torque specifications, diagnostic steps, and scheduled maintenance intervals for these industrial diesel engines.

Because Hatz engines are often installed in equipment built by other manufacturers, having a manual specific to the engine model itself is important for correct rebuild procedures and part specifications, rather than relying on generic equipment documentation. This information benefits DIY owners maintaining equipment powered by Hatz engines, independent repair shops servicing construction and industrial machinery, and workshops that need accurate reference material for these compact, hardworking diesels.