1984 Yamaha IT490 Service and Repair Manual

LIT-11626-04-30 is the factory service manual for the 1984 IT490, model code IT490L. It covers that season on its own, without other models or years mixed into the specification tables.

Match IT490L on the frame plate and the book is confirmed.

What follows is standard Yamaha workshop practice applied to a large-displacement enduro machine. The engine comes apart in the factory sequence, each stage with the inspection measurements needed to judge wear, and goes back together to specified torque. Carburation and ignition settings are published figures. Suspension work is covered in detail front and rear, along with brakes, wheels and controls.

The electrical chapter carries the wiring diagram and the resistance and continuity values for testing. Troubleshooting is organised by symptom, so a starting or running complaint leads through checks in a defined order.