Stephen, Kubota makes BOTH 60 & 180 thermostats. I've used both, no real difference in performance. Some folks will claim there is, but the best "argument" I've heard is use a 160 in hotter water, 180 in colder water.

[url]http://c34.org/bbs/index.php/topic,3212.0.html[/url]

Click the links in the post for more reading.

Good luck.

[quote=StephenK;19177]I currently have a 160 degree thermostat. The Kubota equivalent is 180 degree. Is there a recommended preference? I always thought it was best to run diesels hot so therefore the 180 degree would function better for the engine. Thoughts....?[/quote]

I agree. Our C28 had a 180 thermostat in it, this boat a 160. Hotter is better for diesels.

I have recently been told they initially used cooler thermostats on marine engines to try to cut down the rate of buildup of precipitates from raw water in the engine cooling system. These precipitates clog coolant passages. But with closed circuit systems that seems a lame excuse to me, the only hot thing seeing raw water is the heat exchanger.