If it was in good shape when you put it away, then it's in good shape after it's stored.
Give it a good 'once over' and check all screws, adjustments, and connections, and fire that puppy up!!
New batteries, glow plug, ignitor battery, fuel. You probably wouldn't 'have' to replace the air filter...but I would. I don't think I would tear the carb apart and rebuild it until I suspect it to be bad...It might be o.k. once it gets put back into service.
Don't expect 4 year old tires to last very long either...
Good luck, let us know how it goes.