I have just purchased a 1994 200xri efi mercury, This boat runs great 80% of the time, however the other 20% it will not get over 2000 rpm under a load. When it runs good ( or should i say fast) it has a rough idle but still runs good, when it runs bad ( under a load 2000 rpm max) it actually idles smoother. I have replaced all the fuel lines and filters, stator and both voltage regulators and no fix