Overheating problem.
 

My brother went out in his boat this weekend and ran his engine so hot it quit. After he started back up it had a knock in it. I'm assuming he warped a head and possibly hydraulicked and bent a rod. Anyone have any other ideas? Thanks.

I overheated my old boat because I had a plastic bag wrapped around the drive that I ran over cut off the water supply my temp gauge didn't read anything because there was no water on the sensor. All I saw was the oil psi falling and it stopped After it cooled down it would run but knocked and carried on high I spun bearings. I turned it in to insurance and built the motor they even paid me to pull it and do the work

He most likely spun a rod bearing. Needs to be completely rebuilt.