What do I need to do to successfully winterize my '99 200hp optimax? From what I understand I need to:
-Put stabilizer in fuel and run the outboard.
-change lower unit oil
-spray fogging oil under spark plugs
What else, if anything do I need to do to successfully winterize?
All of the above. Some people also fog their outboard while it's running and then shut it down. This draws the fogging oil into the entire fuel system and coats the cylinder walls with a light mist also.
One hint is to run fuel stabilizer in your tank all season long, which will help keep your fuel as stable as possible during the entire fishing season. This should especially be done if you burn gas with ethanol in it, since ethanol based fuels go bad much faster than those with no ethanol.
It's also a good idea to change the fuel filter on the engine and the water separator filter (if you have one), which is typically mounted in the bilge area.
Another thing you might want to consider is dropping the lower unit and checking the water pump impeller. And change it out if it shows signs of wear.
Some people change their spark plugs immediately after fogging the engine and shutting it down. I disagree with this, however, since those brand new plugs can get fouled in the Spring when you fire the engine up for the first time with all of that fogging oil still in the combustion chambers. When you start the engine for the first time after being fogged, it will tend to smoke quite a bit for the first few minutes of running, as the fogging oil burns off. That heavy fogging oil can wreak havoc with those shiny new spark plugs.
So leave the old plugs in for the winter and for the first trip out in the Spring. And then change them after that first trip is out of the way.
Hope this helps. And I'm sure some others might have some additional things to add.