Replace or not replace a working thermostat?

Hi guys,

Last October I did the winterizing of my "new to me" Sundeck 200 and because I wanted to be anal (plus this is an investment hard to afford) after the drain I did the Anti-freeze removing the thermostat and hoses to fill everything. I noticed that is a good time to replace the thermostat gasket because came apart when remove the thermostat which I bought and I am going to do this weekend. when shopping I did not found the gasket alone and bought the new thermostat with includes the gasket.
Now my question is, should I change the thermostat now that Ill be working there? One side of my brain says "Yes, doesn't hurt anything have a new part, and save the old one just in case" but the other side of my brain says "Dont change something that is working fine, you dont even know if the new one is the same quality, have the same specs, etc"
The boat is 2006 and I dont know if the thermostat has been replaced by the previous owner.

So, I am debating on that, any suggestion? for a mechanic even better.

What brand is the new one ?

scoflaw said:

What brand is the new one ?

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It is a Sierra 18-3648 Thermostat Kit

That should be decent quality. You should be fine either way.

A habit developed from my hot-rodding days was to always replace my thermostat anytime I had to take it out. At the very least, you are resetting the clock on a part that lives in a hostile environment.

bobeast said:

A habit developed from my hot-rodding days was to always replace my thermostat anytime I had to take it out. At the very least, you are resetting the clock on a part that lives in a hostile environment.

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that makes sense, thanks!

Thermostats rarely go bad in a freshwater cooled engine.
Raw (salt) water could be another story.
I’d use the new one since your at it..

lol ... i replaced a working one this season . well , the new one works not better or worse that the old one but i ran in a leak because i failed to resurface the gasket area carefully so had to do the work twice .

if yoy already opened the housing : put a new one in , otherwise don,t touch it