I have a 5.0 GLE with an SX outdrive in a 2004 Starcraft 2015 deckboat. Always has run great at a temp of 180. Took it out for the first time this year and it got hot, up to 210-220. Replaced impellar at recommendation of dealer although it looked fine and had been replaced 2 years ago. Put back in water and same problem. Took boat to dealer and he took the thermostat out and told me to run it for the weekend. Ran great and temp never got over 150. I left it with the dealer and he put a new thermostat in and took it out on the water. Again, ran hot. Dealer took thermostat back out and told me to use for the summer. They checked and there were no blockages anywhere. They said their next guess would be the circulating pump. Anyone have any insight?
