1987 Yamaha G3-E "SUN CLASSIC" (36-VOLT DC MOTOR) Service...
Yamaha's own records list this 1987 machine as the G3-E Sun Classic with a 36-volt DC motor, code G3 - E. The service manual that answers for it is LIT-11616-05-90.
Coverage takes in the 1986 and 1987 model years and the several ways the factory wrote the same car's name, which is worth knowing when you are searching by title rather than by part number. The part number is the dependable reference.
The book itself deals with the drive motor and its control circuit, the charging arrangement, brakes, steering, suspension and body hardware, each with the removal order, the measurement to take and the torque to apply. The wiring diagram shows the harness the car left the factory with, which matters on a machine that has likely seen repairs since.