Guinness Stout is light compared to Aztec brewing's Noche De Las Muertos. That is one big black thick beer. One of my favorites. Another good and appropriate beer is Port's Old Viscosity.
I mean if this is the oil they run in 100k top fuel engines making 10,000 hp, it ought to give any air cooled vtwin the ultimate protection. Haven't posted in a while and figured this would be a good starter.
I absolutely love Maxima oils for my motorcycles but for my aircooled engines I have always run a full synthetic 5w-40 or 5w-50 depending on the engine.
My zero turn kawasaki runs hard and hot and I run schaeffers s9000 5w-50 leftover from a motorcycle trial. It didn't shift well, so I stopped using it and had a few gallons leftover.
Generators, power washers, chipper, push mower etc get 5w-40 M1 turbo diesel truck or rotella T6.
For the price I don't think a good HDEO can be beat. I always go with synthetic to help fight coking and sludging from the heat of aircooled engines.
I don't think I have actually purchased or used a conventional oil in decades. No reason when synthetic is only a few dollars more.