Small Engines (Lawn Mowers, etc.): lawn, murray lawnmower, mechanical problem

Question
I have a murray lawnmower at it seems to sieze up when i pull the cord?  What can it be?

Answer
It could be the oil level is way too high, the flywheel key is  sheared, the engine is seized and several other things.  You need to verify if it is a mechanical problem by trying to turn the engine over with the spark plug out.  If it turns over with the plug out, the issue is either a sheared flywheel key or overfilled oil.  If it doesn't turn with the plug out, something is physically locking the engine such as engine seized, blade contacting deck, etc.  Hope this helps.