1973 Yamaha AT1 Service and Repair Manual

The 1973 AT1 is the last year of the model, and it stays within the coverage of LIT-11613-14-01. Frame code AT1C.

That book was compiled for 1971 to 1973 and reaches well beyond the AT1. The AT2, AT3, CT1, CT1C, CT2, CT3, LT2 and LT3 all appear in it. Yamaha's reasoning was straightforward: the machines share their basic layout, so one manual with variant notes was more use to a dealer than nine thin ones.

Restoration and repair work leans on the same pages again and again. Engine and gearbox teardown sequences, assembly clearances, torque specifications, ignition and fuel settings, wiring diagrams, and structured troubleshooting for the problems these two-strokes actually develop. Nothing here is guesswork; every value comes from Yamaha's own service data. Match the AT1C code first, then work from the section that names it.