[Ray]

Pull the boat out of the water (or remove the ear muffs) and keep the motor in a vertical position for at least ten minutes to ensure all water is drained from the block and passages (outboard motors are self draining and require no anti-freeze for storage). If possible, the engine should be stored in an upright position in the coldest condition possible (rust processes are slowed considerably at low temperatures, and no humidity to promote rust exists below freezing). The worst place to store your outboard is in your basement beside your furnace — high humidity and warmth will seize an engine in no time.
For those that may be storing for extended periods of time or in warm humid conditions, you might want to remove the spark plugs and squirt some additional 2 stroke engine oil or fogger into the cylinders, then roll the engine over by hand to thoroughly coat everything. Re-install the plugs to minimize condensation during the storage period.

Edit: got this online.