I am getting a 4 beep code on my 2002 225hp EFI Mercury. The motor would beep 4 times then stop for a few minutes then repeat. I have what seemed to be good water pressure(changed pump and outside water filter this spring), the outside oil tank was half full and the one under the cover is full to the top. I checked the fuel filter under the cover and all seems good. Later, I was on top and the motor fell off step as if it overheated and cut ignition to half the engine. The motor seems to run fine up to 2000prms but when trying to get on step the alarm goes off and half the cylinders seem to cut off and I have to put to motor in neutral for the alarm to go off again, then idles fine. Can anyone help???