I know rb recomends replacing it after 1 1/2 gallons of hard running, so if you run it easy for the first couple of gallons should be ok. I know Im going to replace mine after 2 or 3 gs.

As far as breakin, im going to do what i always do.

idle for 2 or 3 tanks.
idle to 1/4 throttle for 2 or 3 tanks
idle to 1/2 throttle for a tank or two.
then ill start to lean it out, but ill keep it easy for the first gallon just to be safe
thats how Ive done all my engines and so far the only reason ive toasted and
engine was a piston skirt broke, dont know how but ofna warrented it so its new again. that was after 3 gallons on my 8p