I have a 2011 150hp Yammy 4 stroker, my mechanic told me to always store the motor totally down after giving a good wash and just a light oiling. Mines still as clean as the day I bought it. If I am working on the trailer and the motor needs to be tilted to facilitate it then I will just give a light spray of lithium grease on them as I live near the sea and everything has a tendency to corrode.