I have a 2013 197 with the 5.7 ILMOR engine. About 240 hours (bought it with 210 hrs). 170 degree thermostat installed at around 180 hours. temperature gauge seems to fluctuate between as low as 130 to about 165. Is this normal? does it suggest that the thermostat stays open too long? Or a bad gauge or sensor? I'm glad it's not overheating but running too cool not good either. Any input from IlMOR owners much appreciated.