Possible Overheating?

[quigley5190]

I have a 1997 Sea Ray Sundancer with twin 4.3 L Mercruiser V6. Both engines at idle run around 150 degrees but when running at about 3400-4000 RPM the temperature is around 170-180 Degrees? Is this normal? If not what could be causing it. I changed the thermostats and water pumps/impellers at the beginning of the year.

 

[paultjohnson]

Re: Possible Overheating?

Dunno but my 86 4.3 runs a perfect 140 -145 no matter if its at idle, WOT, on muffs or in the lake. With a 143 Deg stat.. FYI

 

[Don S]

Re: Possible Overheating?

Have a look at this Service Bulletin on an overheat problem above 3000 rpm on an Alpha I Gen II drive.
http://www.boatfix.com/merc/Bullet/95/95_13.pdf