Changed my thermostats this past weekend, noticed my starboard f225 had salt deposits just behind the thermostat. changed out the tstats and cleaned up the salt, started the motor and noticed bubbling through the block. NOT GOOD!!. The block has corroded through. I always flush the engines, changed the anodes and this happens. Brought it to my yamaha guy and he contacted yamaha, The reply was that yamaha was going to give me $500 off a new powerhead. the engine is a 2004 model built in 6/03. total hours of 575. I will contact yamaha myself and see where it goes. I am another yamaha owner that has succumbed to this corrosion issue, My winter project was to inspect the exhausts to see if corrosion exists there, that will be additional costs. I feel that yamaha has to address this issue and stand behind their product. By the way i had asked about trade in on the f225's and the dealers does not really want them in trade due to corrosion issues, that says something.Ill keep you posted