Let me make sure I'm on the correct page; Runs fine at slow speed, gets hot at cruise speed? New issue overnight? What changes have been done to the boat? Any new thru hulls or depth sounders? Any new hardware to the gen-sets exhaust system? Are you running your trim tabs differently? Mother in-law on board? What model gen-set? How come all the good gen-set bugs are so far away from me??
Sorry for not updating.........I found out there was some paint over areas oh the screen from my last Bottom Paint . Cleaned it up , all good now