Was on the way back into weigh in this past sunday afternoon running 4,800 rpms and motor started sounding funny so immeditely slowed down and as i slowed down you could hear some knocking going on and then it shut off on me, tried to re start but it was locked up tight. Yesterday i checked the oil and it has water mixed in with it and the bottom left side cylinder has the milky oil sitting in it and on the spark plug. Im really disappointed at this failure because the engine ony has 344 hours on it, 157 which are 1000 or less, 47 between 3000-4000, 80 between 4000-5000, and 15 from 5000-6000. Oil changes performed no more than 70-80 hours between changes and all other items preformed before scheduled required times. i remember seeing a post a while back asking how many sho owners are out there with over 400 hours on there original power head and now i see why they were asking the question. This has me a little worried if a motor that has been taken care of this well cant break the 400 hour mark will the next powerhead make it past 350 hours.