Hi Jim, I would contact your local CAT dealer and ask them. I replaced my thermostats 2 years ago and CAT bumped up the temp from 180 to 195 with an explanation that the engine achieves a more complete fuel burn at the higher temp...

 

I think that 200˚ is too hot.........it won't hurt the engines but, 200˚ leaves you with no safety margin if/when you get a heat exchanger clogged up or a seawater pump eats one of the blades off its impeller. I think you are better off running at the current thermostat rating. I have 3116's and my engines came with 180˚ thermostats from the factory. As Mark said, Caterpillar couldn't meet emissions goals at that temperature so, they increased the thermostat opening point to 195˚in order to get a more complete fuel burn, lower soot and lower emissions. At 195˚ you have some cushion should you have an engine start to run hot..........at 200˚, you can begin to reduce the throttle and usually get the engine to cool down some, but if you are already at 200 degrees and an engine begins to over heat, you don't have a lot of reaction time. When you get to 210˚ you need to be at idle until the engine cools down below 200˚. If it won't cool down, then you have very few options......go home on one engine, or go tie the boat to a dock somewhere and figure out what the problem is.

 

197 to 199, mine run all day at that temp, regardless of sea water temps. They come up to temp at the same speed and never waiver. Cat says that is within the normal range.

Gotta agree with Frank, it does not leave a lot of room for error.

 

You can add sea water flow sensors for about $300. Early warning system if you get clogged intakes. If you boat in places with lots of floating grass, maybe not a bad idea.

I changed to the new 195 deg version this year, no complaints.

https://www.sbmar.com/product/complete-raw-water-flow-alarm-detector/

 

Mine are the following: idle-192 to 195. Running speed- 197-199. Cat will go til 203 degrees, but if you break 205 you need to be going to idle. This is for the Cat 3196E with 660hp.

 

You can add sea water flow sensors for about $300. Early warning system if you get clogged intakes. If you boat in places with lots of floating grass, maybe not a bad idea.

I changed to the new 195 deg version this year, no complaints.

https://www.sbmar.com/product/complete-raw-water-flow-alarm-detector/

Thanks for you advice Jim

 

You can add sea water flow sensors for about $300. Early warning system if you get clogged intakes. If you boat in places with lots of floating grass, maybe not a bad idea.

I changed to the new 195 deg version this year, no complaints.

https://www.sbmar.com/product/complete-raw-water-flow-alarm-detector/

Cool device...Did you add this too?

 

No. I’m I’m a fresh water lake, not much to plug up the intakes around here.