RE: Improper break-in
sounds like your good to go,I don't think your in any trouble at all.
if the engine was quiting evey once and a while and had time to cool down thats a good thing which probably saved it from any destruction.
the main thing is that there was fuel coming out the pipe,when it was running, that is the coolent,the oil in the fuel really.OS engines can take a beating,some engines require alot of break in time and a real gentile touch for the first few runs.
sounds like your brother got a little ahead of himself in his break in.
for safety's sake I would re-run the proper break in procedure as per the instructions like I origonally suggested, and start over, its a simple process and it sounds like you have a good idea how to do it, then run it a little rich for the first few flights then a little leaner each time.both my OS 46's run best about 1 1/4 turn or so with a little fuel out the pipe and are extremely strong runners.
the engine you have is a great little power house, you might want to remind the bro. if he takes care of it, he will have a machine that can last decades or seconds his choice.
they don't include the directions just for packing, my brother would never read his either