You didn't say how you stored the engine or really what you did with it before you put in in storage.

I had a problem recently with an OS 65LA, seemed to run OK on the ground but dead sticked as soon as it got airborne. Also the needle seemed a bit unresponsive. Its a good job you can see there's a problem before you fly the plane.

Apparently, dirt can get stuck in the 'T' section of the remote needle valve. Take the needle out and remove all the fuel lines then blow through the needle valve area using a can of compressed air (dust remover from Radio Shack or similar). Just to be sure, remove the carb, wash it in alcohol and blow through the fuel inlet in the same way.

Make sure all your fuel lines are clean and have no splits before reassembling the whole kit and kaboodle.

Once you know your fuel supply is clean and unrestricted and you're using the correct plug (A3 or No 8) then you should be good to go...