1978 Yamaha XS750 Service and Repair Manual
XS750E is the model code on the 1978 XS750, and the factory reference for it is part number LIT-11616-XS-70, one volume covering 1977 through 1979.
Where the triple was revised across those three seasons, the specification tables say which code the figure belongs to. That distinction is worth respecting on a machine with a shaft final drive and three carburetors, since the settings are not interchangeable by eye.
The book is arranged for work. Reference data and adjustment values come first, then engine overhaul in factory disassembly order with clearances, wear limits and reassembly torque stated as you go. Clutch, transmission and final drive have their own sections. Chassis chapters cover fork service, rear suspension, wheel bearings and brake overhaul. Ignition timing and charging output are checked against figures, and the electrical chapter includes the complete harness diagram for tracing a fault.