These were famous for their electrical issues. They had an update which includes coil pack and stator. Did you check the start switch? Might check ebay for used electrical parts.
94 Polaris slt 750
Last summer I was preping for the season and the SLT750 would not turn over I check the battery and it was shot so I replaced it. Still nothing. I took the electronics brain cover off and inside I found a moisture corosion mess. I feel that I am pretty good with circuit boards but don't know if I want to takle this. Any suggestions. Look for a used parts or try to repair.:dunno: 
