i have a Searay 175 Sport which has consistently run at 170 deg. for years. Recently, the temp guage is showing about 195 deg. Idling on muffs but then will sometimes fall back to 170, only to drift back up again. I have installed new thermostat and new water temp sender. I have cleaned and coated with dialetic grease the ground bolt on the block and all the leads connected to it, and the ground panel under the dash for the instruments. The guage passes the no ground all the way left, ground to send all the way right test. Infra red termp readings (again, idling on muffs) at the sender location in the thermostat housing are about 160 (when the guage is reading up to 195.). Any other ideas on how to get my temp guage working again?
