I just acquired an '82 with 19k miles on her in pristine condition. I have been searching this forum in every manner that I know how and have not found any information about engine oil recommendations. I have seen suggestions of running Rotella 15w40 and had an mechanic tell me to run DELO. I also a post from 2010 about Mobil 1 MX4t. Any insight and recommendations would be much appreciated as I want to change the oil before I start riding her.