1974 Yamaha DT250A / DT360A Service Manual (207 Pages)

1974 Yamaha DT250A and DT360A Service Manual Scope

• Covers 1974 Yamaha DT250A and DT360A motorcycles, including detailed specifications for the 250cc and 360cc 2-stroke Torque Induction engine configurations
• Official Yamaha publication 450-28197-20
• Contains 120+ exploded-view diagrams, electrical schematics, and tolerance charts
• Accessible from your device as soon as the order is placed
• OCR text layer lets you jump to a torque spec by keyword
• Re-download the file any time, no expiration
• Page spreads stay legible when printed at original size
• This 1974 factory edition provides the primary technical reference for the launch build of both the DT250A and the 360cc displacement variant

Technical Documentation and System Overview

The 1974 Yamaha DT250A and DT360A service manual structures the service data through nine specialized chapters. This documentation begins with machine identification, general technical specifications, and a detailed breakdown of necessary service tools. Subsequent chapters transition into engine tuning, maintenance schedules for high-frequency trail use, and deep-dive technical data covering the clutch, 5-speed transmission, and the Autolube system. The carburetor section documents settings for the Mikuni VM28SS and VM30SS units, while electrical sections isolate differences between the DT250A magneto ignition and the DT360A Capacitor Discharge Ignition systems.

Additional technical data sections provide precise tolerances for engine rebuilds. The cylinder head torque is documented at 2.1–2.5 kg-m, while transmission fluid capacity is specified at 1,000 cc for the DT250A and 1,200 cc for the DT360A. The manual provides detailed clearance limits for piston rings, clutch friction plates, and transmission shaft end play to ensure internal component longevity. Cylinder bore taper limits are listed at 0.05 mm, with out-of-round tolerances defined at 0.01 mm. Spark plug torque is specified at 230–250 in-lbs for secure heat transfer during high-performance operation. Understanding what an OEM service publication covers assists owners in maintaining the 1974 Yamaha DT250A and 1974 Yamaha DT360A systems to factory standards. All service data is for reference only — qualified technicians and original OEM documentation remain the authoritative source for any hands-on work. This 1974 Yamaha DT250A and 1974 Yamaha DT360A service manual documents the complete mechanical and electrical specifications for both models during their initial production cycle.