As soon as i try to put it in gear it dies, why? all of the wiring was redone, maybe was something not done right? or maybe is a wire missing or done wrong? it runs great when you start it up then when you push in clutch and try to change to first gear it stops right away the year of the motor is 1985

At this point I would be looking at the safety switches. There is one on the clutch perch and should be one on the side stand. Disconnect and check switch operation with a multimeter. make sure both are closing as they should. not unusual for the side stand switch to hang up due to oil and road grime down at that level. work the side stand up and down and make sure it goes ALL the way up and contacts the switch. make sure that the clutch switch is opening as it should fully when you pull in the clutch.

There is a side stand cut out switch to stop you riding off with it down, either the plunger on the switch is stuck in or the switch isnt wired up (or not correctly). hope this helps