Atomic 4 Thermostat cleaning

While investigating cooling issues in my Atomic 4 I came across an FAQ at the Moyer Marine site that described cleaning the thermostat every season. "It really is better to use a thermostat in the Atomic 4, and to keep it clean by soaking it in vinegar every season." 

While I have had my thermostat out annually for winterizing, I have never cleaned it. So I decided to give it a try.

Half way clean, after 2 days soaking in vinegar

I had no idea how dirty the thermostat was! In fact, I though that the thermostat had been rusty but, now that it is clean, I realize that the rust was just gunk. 40 years of gunk took 3 days of soaking to clean (and 3 changes of vinegar).

I also wasn't sure what temperature rating my thermostat was rated for so I tested it by boiling it.

The thermostat started opening around 125 degrees Fahrenheit and was fully open around 160 degrees.It was approximately 1/4" open at it's fullest. I'm not sure if either of these are measurements are within spec because I can't find a good reference online. If anyone knows, please comment below.

I'm not sure if my dirty thermostat was the cause of my cooling issues but it couldn't be helping.