Originally Posted by grizz1

Perhaps that wasn't the best phrase to use. It means ¨give it some throttle¨ or ¨put the foot down¨ - nothing to do with running rich.
You want to be a little on the rich side while running in, but not real rich and boggy. Just a little blubbery for those first 8 tanks, then a little leaner for the next 4, then just under race tune for a few more. Then by #15 you should be ready to race. It will still be tight for a while, so don't expect 100% performance or real good economy for at least 1.5 gallons. By then you should be humming real good