1977-1982 Yamaha GT80, GTMXE, GT80G, GT80J, DT80J, DT100D, DT100G, DT100J Factory Service & Supplementary Manual (P/N LIT-11616-03-05)

• Official 175-page Yamaha OEM workshop publication (P/N LIT-11616-03-05)
• Covers 1977–1982 Yamaha GT80, GTMXE, GT80G, GT80J, DT80J, DT100D, DT100G, and DT100J motorcycle variants
• Consolidates supplementary service data into a single reference for 3J8 and 3A3 chassis and engine builds
• Features 35 exploded-view component diagrams and 2 complete wiring schematics for both 80cc and 100cc engine configurations

Factory Documentation Details

This collection provides the essential technical blueprints for the Yamaha GT80, GTMXE, and DT100 series. It bridges multiple supplemental factory releases into one cohesive reference file. Inside, you will find exact mechanical tolerances and maintenance intervals for these classic 2-stroke engines. The literature breaks down internal assemblies, covering the crankshaft, transmission, and clutch. Separate sections map out carburetion tuning, chassis alignment, and intricate electrical system routing. It gives workshop professionals and vintage motorcycle restorers the exact data required to maintain factory standards. Keep in mind that working on vintage motorcycles involves inherent safety risks; utilizing proper protective gear and strictly following shop protocols are critical before beginning any mechanical teardown or electrical testing.

Technical Data Preview

You get immediate access to the raw numbers. The documentation outlines exact specifications for the 72cc GT80 and 97cc DT100 powerplants. Need precise torque values for cylinder head nuts or primary drive gears? It is all charted out. You will also find organized tables detailing ignition timing, spark plug gaps, and oil capacities. For example, the crankshaft assembly width is specified at 38 mm for GT80 models. Cylinder head warp limits are strictly set at 0.03 mm for the 1977–1982 engine series, and ignition timing is pinned at 21° B.T.D.C. at 2,000 r/min. These factory specifications ensure your rebuild stays true to Yamaha's original engineering benchmarks.