I was wondering what octane 650L owners run. My bike is stock except for exhaust, air filter and carb mods. Before I replaced my head gasket I had to run VP Red and 91 50/50 mix. But now I am wondering could I go back to 91. Does the 650L carb mods (drill slide and re jet) affect octane at all? Or maybe it was running lean before. Just interested to see what octane everyone runs.