My father just bought a 1987 Yamaha XJ900 and wants to change the oil before riding it. I am browsing oil manufacturers websites to see what the recommendations are for this motorcycle and they recommend anything from 10w30 to 20w50 as long as it meets JASO MA2 however Shell recommends some PCMO as well, Shell HX7 10w40 as well as Helix Ultra 5w40. I have a lot of HX7 10w40 in my stash and all the jugs say "JASO SG+", what is this spec? Would these oils be safe to use with a wet clutch?