I would second Jky,sfirst post ,,though suppose depends where you live what climate and how long and where it's going to be stored , Not a bad idea to grease the swivell and clamp screws and wind them in & out to their full travel before storage too and re grease the prop ,, I don't like the idea of trapped drops of saltwater festering away .
I don't actually winterise my engines as such as i keep them in the workshop/ celler under the house Josef Fritzle stye,,
After Wiping all over it with an oily rag i then just gently pull/ turn the engine over a few times each month to make sure the parts don't seize up .
after a good end of season run in a tank for 20 mins or so after letting the engine run out of fuel ,
Open the carb drain screw to drain off any fuel that's left ,
dry off ,, squirt some ! not too much wd 40 over the electrics & grease up the throttle linkages .
On me old 2 strokes I used to lay the engine on its front so the cylinders at facing up , remove the plugs. & put a few drops of oil down the cylinder bores turn the engine slowly over a few times to lubricate the piston rings especially if its a 100/1 mix engine ,,then replace the plugs and store upright .
If storing in a shed I would bung up the carb /air intake with some rag ,, keep out spiders or insects .
For draining the fuel line whilst running in a tank i I disconnect the tank end and push the end of a plastic golf tee or the like to jam the valve open as long as it doesent damage the (o) ring then hang it above the engine from the washing line whilst flushing in the tank ,,
with my 4 stroke engine I can get over 20 mins running on tick over with just what's in fuel line & bulb .
Couple of my other (proper )engines that live in the celler too along side the outboards ,, though I doubt the outboards will be still around after 100 years .