As for the thermo switch: Yes, there was a mod on that. It was for people that were having problems with over choking under certain conditions. It
Can that valve be used for decarbing also
Yep, me too.
Yes, that's what it's for.
Sorry for another serial number question, but I am trying to determine the year on my 50HP Merc outboard. Serial number is 0T085912. Below it says 2000