After reading a post by Andrea Rossi in the Sirio's web site, this is the correct Break-In procedure for the S12's

1.- One (1) tank in the bench at WOT with very rich setting of HSN, avoiding it to go on 4 stroke.
COOL DOWN
2.- Three (3) tanks on the track with very rich setting of HSN, and tuning the HSN at the end of third tank to get almost full power.
COOL DOWN
He says after that, the engine will give more power after every new tank.
3.- For 20% Nitro, use .20 head shim and N° / Glowplug.

Which means that Break-In should be done with more or less 300 to 500cc of fuel.

AFM