At 2 gallons I changed my flywheel and noticed it, so more than likely at about a gallon mine was already loose or off the front bearing. I am pretty sure I didn't stop and the front seal just happened to come off when I pulled my flywheel off. Even if you are on the rich side the bearing can go bad. Just because someone may or may not be on the rich side shouldn't really affect the front bearing from going bad. At least in my mind I don't see the correlation of a rich tune = front bearing being bad