To Whom It May Concern: I have a 2014 engine that had been 100% issue free until recently in April 2019 I had it serviced. The shop that performed the work was trustworthy and had performed numerous other maintenance items with never any issues afterward. In this case the engine had been provided the 500 hour oil/filter service and was also looked at more closely for several other routine based checks. The starboard thermostat was removed and the small 1/4" discharge line that is connected to the thermostats on both sides and "tees" into a common line was inadvertantly disconnected. Over the course of less than 3 weeks seawater was entering the cowling and was being pulled into the intake. It was found when i removed the cowling myself to do a routine inspection of the powerhead after a day on the water. I noticed salt residue all over the engine and a significant amount of corrosion. i then located fresh water leaking from the disconnected line while water flushing. I consulted the shop that routinely services my boat and after they performed a careful inspection it was noted with 100% cerainty that the hose had been disconnected during the routine work that had been performed. After the shop owner consulted with a Yamaha master mechanic who he had consulted with in the past it was noted that this had happened numerous times before on similar engines and that the warranty would have covered if still in effect. This is not a warranty based issue, it is a manufacturer defect. It was not advised by TSB or other commication to be a known item that could result in serious damage. My boat and motors were meticulously maintained and if not for the defect would still be in such condition. I was shocked that the master mechanic and my shop representative had consulted with Yamaha local management and were told that there was no recourse. Yamaha should by all rights perform an investigation and gather the information that will prove this is not the fault of a mechanic and that the hose was designed too short. I expect Yamaha to take full responsibility for the damage to this engine by providing a full new powerhead free of charge. Anything less would be a massive failure by Yamaha and its management team to show ownership of responsibility to its valued customers. I will be happy to supply documentation, pictures, other details and statements from maintenance team that performed service if requested. Unhappy and waiting for accountability to be acknowledged by its owner... Michael Kaiser [protected]@gmail.com