This document provides maintenance and service information for KIOTI tractors models DK50S/55(DK501/551). It is divided into chapters that cover general information, the engine, clutch, transmission system, rear axle, brake system, front axle, steering system, hydraulic system, cabin systems, electric systems and safety procedures. The document includes specifications, troubleshooting tips, disassembly/assembly instructions, and maintenance schedules for various intervals such as daily, every 50 hours, every 100 hours and yearly. Safety warnings are provided throughout and indicated with signs for danger, warning and caution.