I break in all my gas engines using Arctic Cat injection oil mixed at 40:1 for the first gallon and 50:1 after that, Why this oil, simple, Snowmobile engines produce more HP/cubic inch (as high as 3.9 hp/cu.in.)than any other production engine made and high horse power loads the internal parts a lot more than our model engines. I worked at a snowmobile dealer for 3 years and NEVER saw an oil related engine problem, besides the manufactures warrenty thier engines and can't afford any oil related problems.
As far as running, I run them full throttle on a test stand for 2 gallons, just to note, that break-in is the last machining and stress relieving process an engine recieves. And the only way I know of to check if the rings really break-in is the leak-down test.
If any are interested and can't find Cat oil I'd use Yamaha 2-S oil.