When I pull cord to start, the cord moves about 4 inches and then stops dead.

You need to pull your spark plug and check that cylinder is not hydrolocked with fuel or oil first, then with plug out see if it will pull the motor over or pull out any farther than it did before. If everything is good there, I would check underneath the deck and see if you can spin the blade by hand,(make sure your spark plug is still out for safety) next I would pull the rewind top off motor and visually inspect the Flywheel and coil gap and look for something possibly binding or catching on the flywheel, I think that model has a flywheel brake, maybe that is not adj. correct.....good luck hope I gave you some ideas, If by chance the cylinder is full of gas..replace needle and seat in carb.