I have a Poulan 3314 that has always started hard. Lately, I have had to remove the pull starter mechanism several times because the rope has jumped the pulley and jammed (needed to use more force than should have). Now the engine will not turn over even with the spark plug removed. The piston will travel about 1/2 a cycle but then clunks to a stop. It feels like solid metal hitting solid metal. Any thought as to the cause?

Hi,
Well you know how the remove the starter, so do that and see if the engine will spin in a complete revolution when done turning the flywheel by hand. If it does not, it is internal and bad news. If it does then check to see if the rope rotor (pulley) has split in the center causing it to expand and bind.
Peace,
Clarke