Small Engines (Lawn Mowers, etc.): masport, pull cord stuck, briggs and stratton, crank shaft

Question
hi.  I have an old lawnmaster with a briggs and stratton quantum xts50 engine (that's the labelling on the outside).
I was mowing the lawn when it slowed down and stopped.  think it ran out of petrol.  put petrol in but now I can't start it as the starter pull cord is stuck solid after coming out about 8 inches.

Answer
hi carol

1st   check the oil level  , is there oil  and how much ?  y / n

2nd is the blade stuck or caught or jammed on something?  y / n

3rd  if you remove the tank   1 x 3/8  unc bolt and 3 x  1/4 unf bolts   -remove  the starter cover  by removing  1 x phillips screw and 4 x 3/8  unc bolts and 1 x 1/4 unf bolt.   
Can the crank shaft turn over feely or is it hard to turn or has something jammed flywheel ?

if the engine spins over ok and no binding and oil is ok and nothing jamming  blade etc
then i would suspect the starter  has jammed or been damaged in some way ?  you will soon see if its the starter !!!!

but if the engine does not turn over freely and feels like something is binding  might have partially seized the engine  

this does not sound good?  but please check and let me know  

cheers paul