cooling question?

[jerry and sons]

I have a 1991 454 boat use to run at 175 degrees, I was running in some heavy seas and my port was running around 185-180. Temp would come back down to 175 at trolling speed. Elbows and risers were just replaced. Any ideas would help!

 

[knuckle47]

Your starting points will include, raw water pump or its impellers, heat exchangers and u-coolers. A reduction in water volume is causing your coolant temps to rise and it is likely due to either the pump or a blockage

 

[makomark]

Two other simple things to check: belt tension and ill-fitting strainer covers.

 

[nightstalker]

I was having the same problem a couple of weeks ago. After going through everything I could think of, it turned out to be semi fowled salt water intakes (sea scum) and loose belt on the water pump. Cleaned intakes, tightened belts, fixed.
Nightstalker