Head scratcher here

[Jetlink]

You mentioned idling on the trailer, no issue. But then you said you take it on the lake to go above idle and that's when you see the temp climb. Have you run it at higher rpm on the trailer to see if the flow is still even between the exhausts?

We have run it at a "high" idle and it climbs a little but nothing that raises any flags. At idle it is about 20-30 degree difference and when you run it on the lake and go to hop on plane the temp shoots up from 130-140 on the port to 205 just getting out of the hole while the starboard side is still ice cold.