after break in of my OS46, the head bolts had loosened up a bit, but you shouldn't be *****g the rpm of your new engine until after at least 5- 10 tanks of fuel OS recomends you run it nice and easy and slopy rich not tached out with no adverse vertical manuevers until full break in of the AX.
1 gal is not alot of fuel for this engine 10 tanks @12oz ea.= 120 oz.almost a gallon your engine is about broken in at that point.
after my first gallon I switched to the OS#8 plug mainly because the one provided,the #3 kept coming loose, but I found it ran alot smoother with the cooler plug.
I run coolpower 10%nitro 18%oil in all my engines 2 and 4 stroke.
you might want to ask a expierenced club member to look your engine over for you, someone who will know a burnt piston and cylinder vs.normal wear and tear it might need to be cleaned of some of the fuel deposits and the bolts tightened, the fuel residue can get prety hard when its been cooked while it was leaking,and could prevent the head from seating properly, but its best to have someone who knows what to look for check it out first hand.
my engine runs great and has been a super reliable performer spinning a 11/5 prop.