running too hot

[SteevieO]

My 2005 with a 3.0 Mercruiser I/O is running too hot. Average temperature is between 200 and up to 225 degrees. Any idea what possible problem could be and ways to determine the cause?

 

[Bt Doctur]

Re: running too hot

worn out impeller, clogged riser, stuck thermostat
to name a few

 

[BradyA]

Re: running too hot

My guess would be a bad impeller.

 

[Don S]

Re: running too hot

The first thing to check on an overheat on any boat is the raw water pump impeller.


http://www.boatfix.com/merc/Servmanl/14/14cover.pdf