kerosene or tranny fluid into the cylinders which is supposed to lube the cylinder walls and free up the rings. Let it soak in there a few days and then try to turn the crank bolt by hand to see if it is seized or will move. If it will move, cycle the cylinders a couple times, then do an oil change, and then try to crank it. Helps to save some initial startup wear which would be substantial with no lubrication in there after sitting so long.