Well for $400 you can't go wrong even if it was a parts motor. Is it carb'd or fuel injected? Post a pic if you can. Assuming its not ate up with corrosion go through the fuel system, cooling system, gear lube, grease it and go. Is it the right shaft length? 20" or 25". With a couple of exceptions all engines are good if they were serviced and cared for during their lives. Basically, the Yamaha V6 was a durable and reliable engine if they are not corroded internally as some early models had exhaust tuner issues and shift shaft corrosion issues.
