2006 Mercury 90 HP Optimax warning alamr at 4000 RPM

[54pack]

Good evening. Had my boat out tonight and every time I reached 4000 RPM the warning alarm sounds with a constant beep and then power is cut way down.

Oil tank was not empty, about 1/6 full and added oil.

From what I have read seems like typically a shift interrupt switch or water in the fuel filter chamber. Any additional suggestions on what to check before taking into a dealer?

TIA

[Orangemanrandy]

Steady alarm at 4000 rpm

I am having the same issue with my 2006 Mercury 115 hp Optimax. At 4000 rpm, a steady alarm will sound and the engine will not let you go any further. A new water pump was installed and the thermostat was checked. It appears that the engine starts to lose water pressure between 3000 and 4000 rpms, to the point that the alarm sounds at 4000. Any help would be appreciated.