2001 250 Evinrude Ficht, model E250FPSX1F, serial G04951258 (I think or 4951255).

I've noticed that at cruising speed my voltage is reading 16-18 volts. So the engine seems to be overcharging the battery. I read somewhere else that there is no regulator but that the charging, like everything else, is controlled by the EMM (computer). True? So to fix this I need to fix/replace the EMM? I just had it "fixed" in July due to the 3-2-1 shutdown problem (I think that's what it's called). Forget if the high voltage started before or after that fix, I think it was before. Thanks.