winterizing motor.

I have a 77 murcury thunderbolt 85hp 2 cycle, what needs to be done to it to winterize.

This is what I do. As I boat in salt water.Run motor for fifteen minutes in tank of fresh water,I do this every time I take the boat out of the water,but as part of the winterizing just in case.Disconnect fuel line and run carbs dry,tilt motor up,if there's anything left it will run out.
Wash engine down with fresh water.Remove plugs,clean them,spray fogging oil into cyls,turn flywheel clockwise by hand a 1/2 dozen times.Easier to do if you drop lower unit before hand
Check all wires and terminals,clean to shiny,a wee dab of dielectric grease on the tightened terminal.
Pump fresh grease into all grease nipples and remove the steering cable,swab out the tube,I use my shotgun rod,and oil,for this I use ordinary mineral engine oil.
Change the lower unit oil,replace the drain and vent washers when you do that,pull the prop,clean off the old grease and add fresh stuff.
I like to put a film of grease on the drive shaft splines,again because I run in salt, and if the impeller is due a change handy to do it now.Then I spray fogging oil all over the powerhead,reassemble,push the boat to the back of the garage and leave 'til spring and hope I didn't forget anything

While the engine is running on that fresh water, Start spraying that fog oil right in the carbs and choke the engine on the fog oil. You want to coat the crank case parts with the fog oil.

Then pull the carb drains.