Cleaned the VST filter and replaced the medium pressure filter as you suggested and the boats running fine again. That really saved my butt-the dealer and the Yamaha service reps didn't have a clue. They wanted the dealer to hook the laptop up to it and re-create the problem on the water-and he's almost an hours drive from the water! IF you're ever out this way (Napa Valley-SF Bay Area) let me know-I owe you a salmon fishing trip or something!