So you're SURE the piston is rotated correctly with the arrow pointing down toward the exhaust? Okay..........if the plug's dry,it's not getting fuel, which means it may not be pulling fuel. The reed valve is in correctly? No chance you blew out a crankseal is there?
Make sure you keep pumping a little 2-stroke oil in there every once in a while until it starts. You could lose you lubrication trying to start it.
Loosen the float bowl,or float bowl drain screw and MAKE SURE you have gas in that carb......FRESH GAS. don-ohio