Brian, Thanks for the advice, I will definitely look into that. Off hand, I believe the only old fuel was leftover in the auxilary tank from the fall of 2012. It was valvetech fuel and I believe the owner said it was treated as well. The main tank was filled completely this spring when the boat was launched. It looks like I am coming away with approximately 150 gallons or so as the previous owner only took it out a couple times this year.
I looked for some Grady White clubs and the closest one is in Massachusetts, nothing local here in Rhode Island.
I know you have 2006 yamaha's so the comparison may be a little off from my 2001's, but any idea what your GPH is? The previous owner claimed 6-8 GPH per motor, of course, dependent on the conditions. Thanks!