How much trolling do you do? I hear comments on here about trollers, especially adding oil to the crankcase without actually doing it. Condensation is a possibility. Heavy trolling means frequent oil changes and/or hard running sessions to drive the moisture out.
A hotter stat helps to drive out moisture. Hottest I saw available and used was 143F.....that's the same temp as a US domestic hot water heater on the N position. Yeah I know water boils at 212F at sea level, but it helps to dry things out.
Can't get too hot as my OT alarms kicked in at around 195F, reset at 170F upon cooling down.