if the engine has been sitting and was running fine when you stored it the glow plug could be gummed up pull it and rinse it in fuel then blow the fuel off the coil and check to see if it burns bright if not then just pop a new one in.
also if there is some gunk in the engine then a electric starter helps with the first few runs, goo that can build up from old fuel residue,old casor oil can really gum the engine up, a couple of runs and it will help clear it out of there.
if after a few tanks and your having trouble running it then a thorough cleaning might be in order,but usually a few tanks of new fuel will help clear out the cobwebbs on a stored engine.