2017 verado 225 hp gauge on smart craft gauge spikes to 137 f to 165f .temp jumps up and down fast or slow speed .at idle yesterday it was 111f my buddys beside me was 145f same motors .water temp was 50f here .puts me in limp mode .been to dealer twice so far dealer has changed impellor which looked bad! and thermostat. Ran good for 2to 3 hrs then happened again Still does same thing temp spikes really fast to 137f rom 165f .water pressure 2.8 at idle .any ideas .i have 2 more tournys still.lost my bag of fish yesterday limped in late