RE: Lightest (smallest) gas engine???
Rich,
The oil recommended by MVVS and Evo for the little engines is the Mobil 2T and it's designed to be used at 32:1 unlike others. Use what you think is best, run the engine in 3 to 5 minute heat cycles for a gallon, will take a day, post your results. I'll be interested to see what your engine does.
Do you have an infrared thermometer and tach?