well I just happen to have here in my hand a brand new 52 ringed 4 stroke lets see what the break in is in the book
ok here we go
1.start the engine per start up procedure
2.Once the engine has started, at full throttle setting, adjust the high speed needle valve to a very(or ''sloppy'') rich position. Let the engine run for two or three minutes.
Stop the engine
3 It says to repeat the procedure with a slightly leaner setting
after about 30 mins of actual run time the engine should be ready to fly
4 Fly the plane with the engine as rich as possibly while still having adequate power
leaning it a little more on each of the next ten flight by then the engine should be able to hold a normal setting

with a big warning at the bottom \
never run this engine lean and always let the engine cool this will prevent any premature wear or damage to the ring

I know everyone means well but I have always followed the book and never had any complaints about any brand engine I have ran
and it's been a few