Just came across this site and since i'm having major problems thought i'd reg. I have an 06 150 opti on a 192 Smokercraft ultima. Brand new out of the box just started overheating although i have good water from the discharge. After having my boat for 3 wks and talking to the Merc rep they think i got 1 of 10 engines across the country that a plate was drilled improperly during manufacture not allowing water to escape the head. never got a warning horn. it did go into idle protection. i was wondering if anybody else has had this problem?