If you took the time to change your Evinrude XD 100 and perform other basic maintenance before putting your ATV in storage, getting your vehicle operational once again should be a cinch. All of the fuel should have been burned out of the engine, so the first line of business is to fill up the tank again and be sure that the oil levels are adequate. Reconnect the battery and ensure that any coverings on the muffler or other openings have been removed.
Even though you probably checked all of the fittings and hardware prior to storage, you can never be too careful. Give the ATV a quick inspection and ensure that all of the moving parts are well lubricated. This is also a good time to examine the fuel line, wheels, steering system and the suspension.