I have a 2012 mercury 60Hp Bigfoot 4 stroke. It has about 223 hours on it. It was running perfect as always. Then one afternoon it went into guardian mode ( limp mode ). It would only rev to 3000 RPMs before going into guardian mode. it will run all day at 2800RPM without going into guardian mode. The computer was showing over heating and the oil pressure fine. I had the system flushed and replace the impeller first, didn't work. Replaced the temp censor , didn't work. I personally replaced all the fuel filters change the oil, lower unit gear oil, nothing worked. I had other mechanics replace solenoids , among other parts chasing this problem. Has anyone had this problem?