This special volume (No. 281) deals with the following topics: functions based on 2-stroke and 4-stroke engines, manual transmission and variomatics, and mixture preparation systems from carburetor to injection system. Maintenance work includes valve adjustment, liquids, filters, tightness, and bodywork on the universal maintenance schedule. Guided troubleshooting provides detailed troubleshooting for the individual repair sections, with measurement work in the mechanical and electrical areas described in individual steps. Components and tests cover engine mechanics, drive, chassis, fuel system, lighting, electrics, starter, generator, ignition, exhaust, and cooling systems, presenting their functions along with troubleshooting and possible assembly work. Circuit diagrams and measurement technology include universal circuit diagrams of the complete electrical system, presented in a resolved representation.