Temperature Alarm at launch

[Rvgetfive]

Hi, new owner of 2004 Cobalt 240. Two weekends in a row, after launching the boat from a cold start, the alarm goes off, the temp gauges shoots from 160 to 180, and the boat sputters when we try to take off.

Takes a few minutes, alarm stops, temp drops back to around 160, boat runs fine the rest of the day, even at startup after stopping for a few hours to hang out on the water. Also, runs fine on Day 2 after being in slip overnight.

Had the impeller changed a few weeks ago prior to starting out for the summer.

Any suggestions?

[Big Block Power]

Sounds like the housing is bad. Losing prime getting air after being out of the water.