1988-1990 Yamaha Enduro 50 / DT 50 / DT50U Service Manual • P/N LIT-11616-06-29

1988–1990 Yamaha DT50U Technical Documentation

• The 1988–1990 Yamaha DT50U official factory service manual covers the Enduro 50, DT 50, and DT50U variants equipped with liquid-cooled 2-stroke engines.
• Official OEM publication (P/N LIT-11616-06-29), 1st edition published in December 1987.
• Contains 100 pages of comprehensive bolt-torque reference tables, extensive electrical wiring schematics, and 23 detailed exploded-view assembly diagrams.
• Available as an instant download the moment payment clears, minimizing downtime in your repair schedule.
• Indexed PDF search covers every chapter and appendix for rapid navigation.
• Optimized for standard US Letter and A4 printing.
• Serves as the definitive factory reference for the 3BK-series DT50U build, providing original service parameters and factory-specified tolerance limits.

Factory Service and Maintenance Documentation

This publication provides a professional-grade technical overview, detailing precise service parameters for the engine, transmission, and chassis. You will find maintenance and periodic inspection data cleanly segmented into accessible chapters. These sections cover critical tasks like cooling system fluid replacement, carburetor tuning, ignition timing checks, and transmission oil service. The manual thoroughly reviews the Autolube system. It outlines pump stroke adjustment and air bleeding procedures while offering diagnostic guidance for troubleshooting hard starting, poor idle, or shifting issues. When performing any maintenance, always adhere strictly to the safety precautions and factory limits outlined in these documents to prevent component damage or personal injury during your workflow.

Yamaha DT50U Specification Highlights

Technical specifications are laid out for absolute precision. The text covers required torque values, clearances, and electrical diagnostics necessary for a successful repair. Mechanics get exact reference values for the 6-speed constant-mesh transmission, ignition coils, and CDI components. For example, cylinder head bolt torque is specified at 32 Nm (23 ft-lbs) within the engine assembly table. Total cooling system capacity is documented at exactly 0.6 liters. You will also find the required spark plug gap specified at 0.7–0.8 mm for the DT50U model. Professionals will find these factory service notes highly valuable for verifying clearances during complex assembly or inspection tasks.