I have twin 150 optimax engines (2007). When either engine reaches the RPM range of 2250 the engine alarm sounds. This happens when i use both motors or either the port or starboard motors. So far I have replaced all the thermostats , water impellers and gaskets, Oil is pumping, and fuel is new, I have also changed the fuel filters, no water was evident. The motors have 115hours on them. Any ideas... The merc dealers around me have no clue and the 2-3 week wait for them to see me is painful with this great weather...
