140 vs 160 degree thermostat in open loop fresh water cooled engine.

cecho

Petty Officer 1st Class
Thread starter
Joined
Jan 29, 2013
Messages
367
I'm pretty sure my boat has a 140 degree thermostat. Would there be any problem with putting a 160 on it? I know that's bad in salt water, but what about fresh water? It seems running the engine at 160 would be a lot better than 140, but I doubt using a 180 would be safe for the engine.


Usually searching for fresh water cooled boats brings up results for a closed loop system. I'm not sure why they call it fresh water cooled. I don't think antifreeze makes water very fresh. :lol:
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
14,517
Re: 140 vs 160 degree thermostat in open loop fresh water cooled engine.

I don't think you'd have a problem with a 160, I use one in salt and I haven't had a problem (pretty much all OMCs had 160s) and some newer Mercs do use a 160. If you put in a 160 it will probably run between 160 and 175 or so. What were your running temps with the 140?
 

Outsider

Lieutenant Junior Grade
Joined
Apr 24, 2007
Messages
1,022
Re: 140 vs 160 degree thermostat in open loop fresh water cooled engine.

What does the manufacturer call for? They usually have a reason ... :)
 
Top