I have been scoping my exhaust at the beginning and end of each season for the last few years (ever since this issue came to light)to check for the corrosion. No problems so far on my 2003 F200TXRB. My local Yami dealer says that they don't see it with the 200 much.
If you don't catch it in time, the oil pan corrodes through and its catastrophic. Its a big job to replace all the parts, (Yamaha has a kit with all of the parts ) and Yamaha recommends replacing the oil pump while you have it apart. If its your motor, and you know how its treated you over the years, I would go with the repairs if it came down to it. If not, I'm with Matt, receipts or run.
