350 Mag MPI Thermostat Replacement ?

[Eischman]

So, after 20 years I have a thermostat that stuck open, on my port engine this past week, I have never replaced one yet but reading some other forums and looking at some replacements I am kind of confused, the replacements say 160 degrees and some people are saying it's more like 170 degrees?
My originals both operated at 152 degrees, not a degree over, for 20 years, did MerCruiser change this for a reason or am reading the wrong forums?

 

[alldodge]

If your motors are raw water cooled (no heat exchanger) it would have 160* Stats. Those with heat exchangers would use a 180*

The boat gauge is not 100% accurate

 

[Eischman]

If your motors are raw water cooled (no heat exchanger) it would have 160* Stats. Those with heat exchangers would use a 180*

The boat gauge is not 100% accurate

They are raw water.
So, you're saying that my original stats are 160* and the SmartCraft and the analog gauges are just reading it lower at 150 degrees?

 

[Scott Danforth]

Yes

 

[alldodge]

Agree, and we're only talking 8*
New Stat may start to open at slight different temp

 

[Eischman]

Thanks, Got It!
Now I only wish MerCruiser/Quicksilver would sell their thermostat as a kit with all gaskets and plastic sleeve, from what I have seen, you have to buy everything separately unless you buy an off brand

 

[alldodge]

Nothing wrong with off brand

 

[Scott Danforth]

Stant is the manufacturer of the OEM thermostat

The sleeve has been both plastic and copper (cut from tubing)

 

[Fun Times]

Merc does offer a kit,… sometimes with a sleeve sometimes not that I’ve seen… here should be one,

Hardin Marine - 160° Thermostat Kit 807252Q5

160° Thermostat Kit 807252Q5

www.hardin-marine.com

Often when they get stuck open, it’s because of debris such as rocks… recall seeing one I thought was welded open.